The UNICORE/X server is the central component of a UNICORE site. It hosts the services such as job submission, job management, storage access, and provides the bridge to the functionality of the target resources, e.g. batch systems or file systems.

For more information about UNICORE visit

1. Getting started

1.1. Prerequisites

To run UNICORE/X, you need the SUN or OpenJDK Java 6 (JRE or SDK). If not installed on your system, you can download it from

UNICORE/X has been most extensively tested on Linux-like systems, but runs on Windows and MacOS as well.

Please note that

  • to integrate into secure production environments, you will need access to a certificate authority and generate certificates for all your UNICORE servers.

  • to interface with a resource management system like SGE or Torque, you need to install and configure the UNICORE TSI.

  • to make your resources accessible outside of your firewalls, you should setup and configure a UNICORE Gateway.

All these configuration options will be explained in the manual below.

1.2. Installation

UNICORE/X can be installed from either a tar.gz or zip archive, or (on Linux) from rpm/deb packages.

To install from the tar.gz or zip archive, unpack the archive in a directory of your choice. You should then review the config files in the conf/ directory, and adapt paths, hostname and ports. The config files are commented, and you can also check the configuration guide

To install from a Linux package, please use the package manager of your system to install the archive.


Using the Linux packages, you can install only a single UNICORE/X instance per machine (without manual changes). The tar.gz / zip archives are self contained, and you can easily install multiple servers per machine.

The following table gives an overview of the file locations for both tar.gz and Linux bundles.

Table 1. Directory Layout
Name in this manual tar.gz, zip rpm Description




Config files




Java libraries




Log files




Start/stop scripts




Init script

1.2.1. Starting/Stopping

There are two scripts that expect to be run from the installation directory. To start, do

cd <basedir>

Startup can take some time. After a successful start, the log files (e.g. LOG/startup.log) contain a message "Server started." and a report on the status of any connections to other servers (e.g. the TSI or global registry).

To stop the server, do:

cd <basedir>

Using the init script on Linux, you would do (as root)

etc/init.d/unicore-unicorex start|stop

1.2.2. Log files

UNICORE/X writes its log file(s) to the LOG directory. By default, log files are rolled daily, There is no automated removal of old logs, if required you will have to do this yourself.

Details about the logging configuration are given in this section.

2. Configuration of UNICORE/X

2.1. Overview of the main configuration options

UNICORE/X is a fairly complex software which has many interfaces to other UNICORE components and configuration options. This section tries to give an overview of what can and should be configured. The detailed configuration guide follows in the next sections.

2.1.1. Mandatory configuration

  • Certificates and basic security: UNICORE uses X.509 certificates for all servers. For UNICORE/X these are configured in the wsrflite.xml config file

  • Attribute sources: to map clients (i.e. X.509 certificates) to local attributes such as user name, groups and role, various attribute sources are available. For details, consult the attribute sources section.

  • Backend / target system access: to access a resource manager like SGE or Torque, the UNICORE TSI needs to be installed and UNICORE/X needs to be configured accordingly. Please consult the XNJS section.

UNICORE/X has several sub-components. These are configured using several config files residing in the CONF directory, see the installation guide for the location of the CONF directory.

2.2. Config file overview

The following table indicates the main configuration files. Depending on configuration and installed extensions, some of these files may not be present, or more files may be present.

UNICORE/X watches some most configuration files for changes, and tries to reconfigure if they are modified, at least where possible. This is indicated in the "dynamically reloaded" column. are indicated.

Table 2. UNICORE/X configuration files
config file usage dynamically reloaded


General settings, startup behaviour, storages, AIP setup



Services to be deployed, SSL settings, Web server settings



Backend, installed applications, resources



Back end properties



Back end properties preconfigured for the Perl TSI


logging levels, logfiles and their properties



Access control policy for securing the web services

yes, via xacml2.config (do touch xacml2.config to trigger)


Configure the XACML2 access control component



Configure the use of UVOS (optional attribute source)



A file mapping user DNs to local attributes (optional attribute source)



Access control file for remote monitoring using the Java management extensions (JMX)


2.3. Settings for the UNICORE/X process (e.g. memory)

The properties controlling the Java virtual machine running the UNICORE/X process are configured in

  • UNIX: the start script in the BIN directory

  • Windows: the "conf\\wrapper.conf" configuration file

These properties include settings for maximum memory, and also the properties for configuring JMX, see the admin guide for more on JMX.


2.4. Config file formats

UNICORE/X uses two different formats for configuration.

2.4.1. Java properties

  • Each property can be assigned a value using the syntax "name=value"

  • Please do not quote values, as the quotes will be interpreted as part of the value

  • Comment lines are started by the "#"

  • Multiline values are possible by ending lines with "\", e.g.

      name=value1 \

In this example the value of the "name" property will be "value1 value2".

2.4.2. XML

Various XML dialects are being used, so please refer to the example files distributed with UNICORE for more information on the syntax. In general XML is a bit unfriendly to edit, and it is rather easy to introduce typos.


It is advisable to run a tool such as xmllint after editing XML files to check for typos

2.5. Integration of UNICORE/X into a UNICORE infrastructure

Since UNICORE/X is the central component, it is interfaced to other parts of the UNICORE architecture, i.e. the Gateway, the Registry and the TSI.

2.5.1. Gateway

The gateway address is usually hard-coded into CONF/wsrflite.xml, and on the gateway side there is an entry VSITE_NAME=address pointing to the UNICORE/X container. In some scenarios it’s convenient to auto-register with a gateway. This can be enabled using the following properties.

Table 3. Gateway settings
config file property name range of values description modifyable at runtime


Base URL


the host/port of the gateway




true or false

whether autoregistration should be enabled



an integer

registration refresh interval in seconds


true or false

whether gateway assertions must be signed (see also security)



true or false

whether UNICORE/X should check if the gateway is up during startup



To use the autoregistration feature, the gateway configuration must be set up accordingly

2.5.2. Registry

It is possible to configure UNICORE/X to contact one or more external or "global" Registries in order to publish information on crucial services there. Most of the following properties deal with the automatic discovery and/or manual setup of the external registries being used.

Table 4. Registry settings
config file property name range of values description modifyable at runtime



"true", "false"

whether to publish service information in an external registry



a valid URL

use this URL for external registry if automatic discovery is switched off or fails



more valid URLs

additional registry URLs



a long value

alive-check interval for registry entries in seconds ; an external registry will enforce its own value



"true", "false"

if set to "true", try to autodiscover the external registry via UDP multicast


2.6. Startup code

In order to provide a flexible initialization process for the UAS, we introduce a property named "uas.onstartup", which is defined in the file "uas.config". The value string of this property consists of a whitespace separated list of java classes which must be implementing the "Runnable" interface. Many extensions for UNICORE/X rely on an entry in this property to initialise themselves.

Table 5. Startup code
class name description usage


initialises the job management system and the "local" registry; should usually be run on startup

normal UNICORE/X servers


initialises the OGSA-BES job management system

UNICORE/X servers that expose BES services


sets up the CIS infoprovider

UNICORE/X servers that want to provide information in GLUE2 format or want to be visible in the CIS

if available, publishes the GridBeanService to the registry

UNICORE/X servers that host a Gridbean service


creates and deploys a single instance of the SMS that is shared between users, named default_storage

if a shared storage is required

2.7. Security

2.7.1. Overview

Security is a complex issue, and many options exist. On a high level, the following items need to be configured.

  • SSL setup (keystore and truststore settings for securing the basic communication between components)

  • Attribute sources configuration (which will map Grid users to local properties such as role, Unix login and groups)

  • Access control setup (controlling in detail who can do what on which services)

  • Message level security (message signatures)

2.7.2. SSL configuration

Here you configure the server identity and the certificates of other services that want to contact this server.

Table 6. SSL configuration
config file property name range of values description



Name of keystore file

The keystore must contain at least one private/public keypair



Keystore type


Keystore password


Alias of the key to use


"true" or "false"

Whether to require client-authentication


Name of truststore file

The truststore contains certificates that are trusted by the server




Truststore password

2.7.3. Attribute sources configuration

Attribute sources provide information about which local role and properties a Grid user has. UNICORE knows several attribute sources which can be combined using various combining algorithms. These are configured in the uas.config file. Due to the complexity, the description of the configuration options can be found in a separate chapter.

2.7.4. Access control configuration

Access control works by checking a Grid user’s attributes (obtained from the attribute sources) against a set of policies. Again, several options exist, which are described in a separate chapter.

2.7.5. Message signatures

UNICORE/X will require important messages (like job submissions or file exports). The property controlling this is - If set to true, signatures are required.

2.8. Configuring the XNJS and TSI

Information on the configuration of the XNJS and TSI backend can be found here.

2.9. Configuring storages on TargetSystem instances

Each TargetSystem instance can have one or more storages attached to it. Usually, only the HOME storage is created, which allows users access their home directory on the target system. You can add storages easily, using configuration entries in uas.config.

Table 7. Additional storages
config file property name range of values description



disambiguates several configuration entry sets


FIXEDPATH: mapped to a fixed directory, VARIABLE: resolved using a lookup, CUSTOM: specified class is used


Denotes a path or the name of an environment variable (depending on the type)

Java class name

Java class to use, only necessary when type is CUSTOM

Space-separated protocol names

Which protocols to enable, default is "BFT RBYTEIO"

Here, "N" stands for an identifier (e.g. 1,2, 3, …) to distinguish the storages. For example, to configure two storages, one named TEMP pointing to "/tmp" and the other named DEISA_HOME pointing to "$DEISA_HOME", you would add the following configuration entries in uas.config: BFT$DEISA_HOMES

# example for a custom SMS implementation (e.g. for Hadoop or iRODS)

Note that you can optionally control the file transfer protocols that should be enabled for each storage.

2.9.1. Controlling target system’s storage resources

By default storage resource names (used in storage address) are formed from the owning user’s xlogin and the storage type name, e.g. "someuser-Home". This is quite useful as users can write a URL of the storage without prior searching for its address. However if the site’s user mapping configuration, maps more then one grid certificate to the same xlogin then this solution is not acceptable: only the first user connecting would be able to access her/his storage. This is as resource owners are expressed as grid user names (certificate DNs) and not xlogins. To have an unique, but dynamically created and non user friendly names of storages (and solve the problem of non-unique DN mappings) set this option in uas.config:

If you want to disable the default "Home" storage, you can set the following property in uas.config:


2.10. Configuring the StorageFactory service

The StorageFactory service allows clients to dynamically create storage instances. These can have different types, for example you could have storages on a normal filesystem, and other storages on an Apache Hadoop cluster.

The basic property controls which storage types are supported

uas.storagefactory.types=TYPE1 TYPE2 ...

Each supported storage type is configured using a set of properties

uas.storagefactory.TYPE1.description=GPFS file system
uas.storagefactory.TYPE1.fixedpath=GPFS file system
uas.storagefactory.TYPE1.protocols=UFTP BFT

# if this is set to true, the directory corresponding to a storage instance will
# be deleted when the instance is destroyed. Defaults to "true"

The "path" parameter determines the base directory used for the storage instances (i.e. on the backend), and the unique ID of the storage will be appended automatically.

The "cleanup" parameter controls whether the storage directory will be deleted when the storage is destroyed.

The "protocols" parameter controls which file transfer protocols should be enabled. By default, "BFT" and "RBYTEIO" will be enabled.

If you have a custom storage type, an additional "class" parameter defines the Java class name to use. For example:


2.11. HTTP proxy, timeout and web server settings

The UNICORE Services Environment container has a number of settings related to the web server and to the HTTPClient library used for outgoing HTTP(s) calls. These are shown in the following two tables.

Table 8. Web server options
property name range of values default value description




Maximum number of threads for Jetty




Minimum number of threads




Milliseconds before an idle connection will be timed out




If the number of free threads is below this value, idle connections will be timed out quicker




under "low resource" condition, milliseconds before an idle connection will be timed out




Milliseconds before an idle connection will be timed out




The size of the largest data chunk that will not be compressed (if the client supports gzip)




Buffer size used for gzip compression

Table 9. Outgoing HTTP call options
property name range of values default value description




Socket connection timeout in millis




Socket read timeout in millis



HTTP proxy host



HTTP proxy port



Proxy server user



Proxy server password



Space separated list of host name fragments which are not proxied

3. Administration

3.1. Controlling UNICORE/X memory usage

You can set a limit on the number of service instances (e.g. jobs) per user. This allows you to make sure your server stays nicely up and running even if flooded by jobs. To enable, edit CONFwsrflite.xml and add properties, e.g.

  <property name="unicore.maxInstancesPerUser.JobManagement" value="200"/>
  <property name="unicore.maxInstancesPerUser.FileTransferBFT" value="20"/>

The last part of the property name is the service name as defined in wsrflite.xml.

When the limits are reached, the server will report an error to the client (e.g. when trying to submit a new job).

3.2. Logging

UNICORE uses the Log4j logging framework. It is configured using a config file. By default, this file is CONF/ To change the default, edit the start script (BIN/ or, on Windows, the CONF/wrapper.conf. The config file is specified with a Java property log4j.configuration.


You can change the logging configuration at runtime by editing the file. The new configuration will take effect a few seconds after the file has been modified.

By default, log files are written to the the LOGS directory.

The following example config file configures logging so that log files are rotated daily, and the file name includes the date/time.

# Set root logger level to INFO and its only appender to A1.
log4j.rootLogger=INFO, A1

# A1 is set to be a rolling file appender with default params

#configure daily rollover: once per day the uas.log will be copied
#to a file named e.g. uas.log.2008-12-24

# A1 uses the PatternLayout
log4j.appender.A1.layout.ConversionPattern=%d [%t] %-5p %c{1} %x - %m%n

Within the logging pattern, you can use special variables to output information. In addition to the variables defined by Log4j (such as %d), UNICORE defines several variables related to the client and the current job.

Variable Description


the distinguished name of the current client


the unique ID of the currently processed job

A sample logging pattern might be

log4j.appender.A1.layout.ConversionPattern=%d [%X{clientName}] [%X{jobID}] [%t] %-5p %c{1} %x - %m%n

For more info on controlling the logging we refer to the log4j documentation:

Log4j supports a very wide range of logging options, such as date based or size based file rollover, logging different things to different files and much more. For full information on Log4j we refer to the publicly available documentation, for example the Log4j manual.

3.2.1. Logger categories, names and levels

Logger names are hierarchical. In UNICORE, prefixes are used (e.g. "") to which the Java class name is appended. For example, the XUUDB connector in UNICORE/X logs to the "" logger.

Therefore the logging output produced can be controlled in a fine-grained manner. Log levels in Log4j are (in increasing level of severity) TRACE, DEBUG, INFO, WARN, ERROR, amd FATAL.

For example, to debug a security/authorisation problem in the UNICORE/X security layer, you can set

If you are just interested in XUUDB related output, you can set

so the XUUDBAuthoriser will log on DEBUG level, while the other security components log on INFO level.

Here is a table of the various logger categories

Log category Description



Security layer

Service operational information

Information related to job execution


XNJS subsystem (execution engine)


TSI subsystem (batch system connector)


Client calls (to other servers)


Underlying services environment (WSRF framework)


Please take care to not set the global level to TRACE or DEBUG for long times, as this will produce a lot of output.

3.3. Administration and monitoring

The health of a UNICORE/X container, and things like running services, lifetimes, etc. can be monitored in several ways.

3.3.1. Commandline client (UCC)

It is possible to use the UNICORE commandline client (UCC) to list jobs, extend lifetimes, etc.

The trick is to configure UCC so that it uses the server certificate of the UNICORE/X server, so that UCC will have administrator rights. Also you should connect directly to UNICORE/X, not to the registry as usual. Here is an example UCC configuration file. Say your UNICORE/X server is running on myhost on port 7777, your preferences file would look like this


Note that the registry URL points directly to the UNICORE/X server, not to a gateway.


The main UCC commands that are useful are the list-jobs, list-sites and wsrf commands. Using list-jobs you can search for jobs with given properties, whereas the wsrf command allows to look at any resource, or even destroy resources.

To list all jobs on the server belonging to a specific user, do

ucc list-jobs -f Log contains <username>

where username is some unique part of the user’s DN, or the xlogin. Similarly, you can filter based on other properties of the job.

The wsrf command can be used to destroy resources, extend their lifetime and look at their properties. Please see "ucc wsrf -h" for details.


ucc wsrf getproperties https://myhost:7777/services/TargetSystemFactory?res=default_target_system_factory

3.3.2. Java Management Extensions (JMX)

Using the Java Management Extensions, you can monitor any Java virtual machine using (for example) a program called "jconsole" that is part of the Sun/Oracle Java SDK. It allows to check memory and thread usage, as well as access to application specific management components ("MBeans").

Connecting to a running Java VM locally is always possible, remote access needs to be specially configured. To enable remote access to JMX, please check the start script of UNICORE/X. There several system properties are defined that enable and configure remote access to JMX.

#enable JMX (use jconsole to connect)
#enable JMX remote access protected by username/password

The password file "conf/jmxremote.password" must contain lines of the form "username=password", and must have its permissions set to "rw for owner only" (at least on Unix).

Using jconsole, you can now connect from a remote machine.

4. Security concepts in UNICORE/X

This section describes the basic security concepts and architecture used in UNICORE/X. The overall procedure performed by the security infrastructure can be summarised as follows:

  • the incoming message is authenticated by the SSL layer

  • extract the information used for authorisation from the message sent to the server. This information includes: originator of the message(in case the message passed through a UNICORE gateway), trust delegation tokens, incoming VO membership assertions, etc.

  • deal with trust delegation

  • generate or lookup attributes to be used used for authorisation in the configured attribute sources

  • perform policy check by executing a PDP request

All these steps can be switched on/off, and use pluggable components. Thus, the security level of a UNICORE/X server is widely configurable

4.1. Security concepts

4.1.1. Identity

A server has a certificate, which is used to identify the server when it makes a web service request. This certificate resides in the server keystore, and can be configured in the usual config file (see the configuration reference.

4.1.2. Security tokens

When a client makes a request to UNICORE/X, a number of tokens are read from the message headers. These are placed in the security context that each WSRF instance has. Currently, tokens are the certificates for the UNICORE consignor and user, if available. Also, trust delegation assertions are read, and it is checked if the message is signed.

4.1.3. Resource ownership

Each service is owned by some entity identified by a distinguished name (X500 Principal). By default, the server is the owner. When a resource is created on user request (for example when submitting a job), the user is the owner.

4.1.4. Trust delegation

When the user and consignor are not the same, UNICORE/X will check whether the consignor has the right to act on behalf of the user. This is done by checking whether a trust delegation assertion has been supplied and is valid.

4.1.5. Attributes

UNICORE/X retrieves user attributes using either a local component or a remote service. In the default configuration, the XUUDB attribute service is contacted. See the attribute sources guide for more information.

4.1.6. Policy checks

Each request is checked based on the following information.

  • available security tokens

  • the resource owner

  • the resource accessed (e.g. service name + WSRF instance id)

  • the activity to be performed (the web method name such as GetResourceProperty)

The validation is performed by the PDP (Policy Decision Point). The default PDP uses a list of rules expressed in XACML 2.0 format that are configured for the server. The PDP section describes how to configure different engines for policy evaluation including a remote one.

4.1.7. Authorisation

A request is allowed, if the PDP allows it, based on the user’s attributes.

4.1.8. Proxy certificate support

UNICORE clients can be configured to create a proxy certificate and send it to the server. On the server, the proxy can be used to invoke GSI-based tools. Please read the proxy section about the configuration details.

5. Configuring attribute sources

The authorization process in UNICORE/X requires that each Grid user (identified by an X.509 certificate or just the DN) is assigned some attributes such as her role.

So the single most important item for security configuration is selecting and maintaining a so called attribute source, which is used by UNICORE/X to assign attributes to Grid users.

Several attribute sources are available, that can even be combined for maximum flexibility and administrative control.

To configure the attribute sources, the property in the uas.config file is used. This is a space-separated list with attribute sources names, where the named attribute sources will be queried one after the other, allowing you to query multiple attribute sources, override values etc.

A second property,, allows you to control how attributes from different sources are combined.

For example, the following configuration snippet

# Authorisation attribute source configuration

# Combining policy

will declare two attribute sources, "XUUDB" and "FILE", which should be both queried and combined using the MERGE_LAST_OVERRIDES policy.

Since all attribute sources will be queried, it has to be defined how attributes will be combined. For example, assume you have both XUUDB and FILE, and both return a xlogin attribute for a certain user, say "xlogin_1" and "xlogin_2".

The different combining policies are

  • MERGE_LAST_OVERRIDES : new attributes override those from previous sources. In our example, the result would be "xlogin_2".

  • FIRST_APPLICABLE : the attributes from the first source that returned a non empty list of attributes are used. In our case this would be "xlogin_1". If there were no xlogin attribute for the user in XUUDB then "xlogin_2" would be returned.

  • FIRST_ACCESSIBLE : the attributes from the first source that is accessible are used. In our case this would be "xlogin_1". This policy is useful for redundant attribute sources. E.g. you can configure two instances of XUUDB with the same users data; the 2nd one will be tried only if the first one is down.

  • MERGE : attributes are merged. In our example, the result would be "xlogin_1, xlogin_2", and the user would be able to choose between them.

Each of the sources needs a mandatory configuration option defining the Java class, and several optional properties that configure the attribute source. In our example, one would need to configure both the "XUUDB" and the "FILE" source:

Additionally you can mix several combining policies together, see "Chained attribute source" below for details.

5.1. UNICORE incarnation attributes

Precisely speaking UNICORE uses user’s attributes for two purposes:

  • to perform user incarnation, i.e. map the grid user to the local system,

  • to authorize the user.

Note that actual names of the attributes presented here are not very important. Real attribute names are defined by attribute source (advanced attribute sources, like UVOS/SAML attribute source, even provide a possibility to choose what attributes are mapped to internal UNICORE attributes. Therefore it is only important to know the concepts represented by the below internal attributes. On the other hand values which are defined below are important.

The attributes in UNICORE are multi-valued.

There are several special attributes used for incarnation:

  • Xlogin - specify what local user id (in UNIX so called uid) should be assigned for the grid user.

  • Group - specify the primary group (primary gid) that the grid user should get.

  • Supplementary groups - specify all supplementary groups the grid user should get.

  • Add operating system groups - boolean attribute saying whether groups assigned to the Xlogin (i.e. the local uid of the grid user) in the operating system should be additionally added for the grid user.

  • Queue - override IDB queues setting for the particular user, defining available BSS queues.

There is one special authorization attribute:

  • role - represents abstract users role. The role is used in a default (and rarely changed) UNICORE authorization policy and in authorization process in general. There are several possible values that make sense:

  • user - value specifies that the subject is allowed to use the site as a normal user (submit jobs, get results, …)

  • admin - value specifies that the subject is an admin and may do everything. For example may submit jobs, get results of jobs of other users and even delete them.

  • trustedAgent - this value is used to express that the subject may act as any user the subject wants. E.g. if John has this role then can get Marry’s job results and also submit job as Frank. It is highly suggested not to use this role, its support is minimal mostly for backwards compatibility.

  • anything else - means that user is not allowed to do anything serious. Some very basic, read-only operations are allowed, but this is technical detail. It is a good practice to use value banned in such case.

Finally UNICORE can consume other attributes. All other attributes are used only for authorization. Currently all such additional attributes which are received from attribute source are treated as XACML attributes and are put into XACML evaluation context. This feature is rather rarely used, but it allows to create a very fine grained authorization policies, using custom attributes.

Particular attribute sources define how to assign these attribute to users. Not always all are supported, e.g. XUUDB can not define per-user queues and offers only Group attribute for controlling users' groups.

After presenting all special UNICORE attributes it must be noted that those attributes are used in two ways. Their primary role is to strictly define what is allowed for the user. For instance the Xlogin values specify the valid Xlogins from which the user may choose one. One exception here is Add operating system groups - user is always able to set this according to his/her preference.

The second way of using those attributes is to specify the default behavior, when the user is not expressing a preference. E.g. a default Group (which must be single valued) specify which group should be used if the user didn’t provide any.

Attribute sources define the permitted values and default values for the attributes in various ways. Some use conventions (e.g. that first permitted value is a default one), some use pair of real attributes to define each of UNICORE attributes.

5.2. XUUDB

The XUUDB is the standard option in UNICORE. It has the following features

  • Web service interface for querying and administration. It is suitable for serving data for multiple clients. Usually it is deployed to handle attributes for a whole grid site.

  • Access protected by client-authenticated SSL

  • Supports the xlogin, role and project attributes (where project maps to Unix groups)

  • Multiple xlogins per certificate or DN, where the user can select one

  • Entries are grouped using the so-called Grid component ID (GCID). This makes it easy to assign users different attributes when accessing different UNICORE/X servers.

To enable and configure the XUUDB, set the following properties in uas.config. XUUDB ...<xuudbhost><xuudbport><your_gcid>

Full XUUDB documentation is available from http.://

5.3. UVOS

The UNICORE Virtual Organisation Service (UVOS) is a powerful tool for managing access based on the concept of virtual organisations. A detailed description and configuration guidance can be obtained from

5.4. File attribute source

In simple circumstances, or as an addition to a XUUDB or UVOS, the file attribute source can be used. As the name implies a simple map file is used to map DNs to xlogin, role and other attributes. It is useful when you don’t want to setup an additional service (XUUDB or UVOS) and also when you want to locally override attributes for selected users (e.g. to ban somebody).

To use, set FILE ...<your map file><strict|regexp>

The map file itself has the following format:

<?xml version="1.0" encoding="UTF-8"?>
   <entry key="USER DN">
      <attribute name="role">
      <attribute name="xlogin">

You can add an arbitrary number of attributes and attribute values.

The matching option controls how a client’s DN is mapped to a file entry. In strict mode, the canonical representation of the key is compared with the canonical representation of the argument. In regexp mode the key is considered a Java regular expression and the argument is matched with it. When constructing regular expressions a special care must be taken to construct the regular expression from the canonical representation of the DN. The canonical representation is defined here. (but you don’t have to perform the two last upper/lower case operations). In 90% of all cases (no multiple attributes in one RDN, no special characters, no uncommon attributes) it just means that you should remove extra spaces between RDNs.

The evaluation is simplistic: the first entry matching the client is used (which is important when you use regular expressions).

The attributes file is automatically refreshed after any change, before a subsequent read. If the syntax is wrong then an error message is logged and the old version is used.

Recognized attribute names are:

  • xlogin

  • role

  • group

  • supplementaryGroups

  • addOsGroups (with values true or false)

  • queue

Attributes with those names (case insensitive) are handled as special UNICORE incarnation attributes. The correspondence should be straightforward, e.g. the xlogin is used to provide available local OS user names for the client.

For all attributes except of the supplementaryGroups the default value is the first one provided. For supplementaryGroups the default value contains all defined values.

You can also define other attributes - those will be used as XACML authorization attributes, with XACML string type.

5.5. Chained attribute source

Chained attribute source is a meta source which allows you to mix different combining policies together. It is configured as other attribute sources with two parameters (except of its class): order and combiningPolicy. The result of the chain attribute source is the set of attributes returned by the configured chain.

Let’s consider the following example situation where we want to configure two redundant UVOS servers (both serving the same data) to achieve high availability. Additionally we want to override settings for some users using a local file attribute source (e.g. to ban selected users).

# The main chain configuration: FILE

# The FILE source cfg:<your map file>

# The UVOS_CLUSTER is a sub chain: UVOS2

# And configuration of the two real sources used in the sub chain:

6. The UNICORE persistence layer

UNICORE/X stores its state in data bases. The information that is stored includes

  • user’s resources (instances of storage, job and other services)

  • jobs on the XNJS

The job directories themselves reside on the target system, but UNICORE keeps additional information (like, which Grid user owns a particular job).

The data on user resources is organised by service name, i.e. each service (for example, JobManagement) stores its information in a separate database table (having the same name as the service, e.g. "JobManagement").

Job information is stored in a table named "JOBS", while finished jobs go into a table called "FINISHED_JOBS".

The UNICORE persistence layer offers two kinds of storage:

  • on the filesystem of the UNICORE/X server (using the H2 database engine)

  • on a database server (MySQL, or the so-called server mode of H2)

While the first one is very easy to setup, and easy to manage, the second option allows advanced setups like clustering/load balancing configurations involving multiple UNICORE/X servers sharing the same persistent data.

Data migration from one database system to another is in principle possible, but you should select the storage carefully before going into production. In general, if you do not require clustering/load balancing, you should choose the default filesystem option, since it is less administrative effort.

6.1. Configuring the persistence layer

Peristence properties are configured in two files:

  • wsrflite.xml for all service data

  • xnjs.xml (or xnjs_legacy.xml) for job data

It is recommended to specify a configuration file using the persistence.config property. Thus, persistence configuration can be easily shared between the components (XNJS and WSRFlite). If the "persistence.config" property is set, the given file will be read as a Java properties file, and the properties will be used. However, "local" properties will override the ones given in the file.


All properties can be specified on a "per table" basis, by appending ".<TABLENAME>" to the property name. This means you can even select different storage systems for different data, e.g. store service data on the filesystem and jobs in MySQL. The table name is case-sensitive.

Table 10. Basic configuration options
property name default value description


name of a config file to read



name of the Java class


(implemention class may provide their own)

Java class name of the JDBC driver


name of the database to connect to


database user name


database password


database server host


depends on the implementation

database server port

6.1.1. Caching

By default, caching of data in memory is enabled. It can be switched off and configured on a per-table (i.e. per entity class) basis. If you have a lot of memory for your server, you might consider increasing the cache size for certain components.

The following properties are used to control the caching behaviour

Table 11. Caching options
property name range of values default value description




"true" or "false" to enable/disable caching for the given table




maximum number of elements to keep in the cache

For example, to set the maximum size of the JOBS cache to 1000, you’d configure


6.1.2. The H2 engine

H2 is a pure Java database engine. It can be used in embedded mode (i.e. the engine runs in-process), or in server mode, if multiple UNICORE servers should use the same database server. For more information, visit

Table 12. Additional configuration for H2
property name range of values default value description


name of the directory for storing data


"true" or "false"


whether to connect to a h2 server using tcp


String denoting an Integer


in-memory cache size for H2 in kilobytes

Connection URL

In embedded mode (i.e. the default non-server mode), the connection URL is constructed from the configuration properties as follows


In server mode, the connection URL is constructed as follows


6.1.3. The MySQL Engine

The MySQL database engine does not need an introduction. To configure its use for UNICORE persistence data, you need to set


To use MySQL, you need access to an installed MySQL server. It is beyond the scope of this guide to describe in detail how to setup and operate MySQL. The following is a simple sequence of steps to be performed for setting up the required database structures.

  • open the mysql console

  • create a dedicated user, say unicore who will connect from some server in the domain "" or from the local host:

CREATE USER 'unicore'@'' identified by 'some_password' ;
CREATE USER 'unicore'@'localhost' identified by 'some_password' ;
  • create a dedicated database for use by the UNICORE/X server:

CREATE DATABASE 'unicore_data_demo_site';
USE 'unicore_data_demo_site';
  • allow the unicore user access to that database:

GRANT ALL PRIVILEGES ON 'unicore_data_demo_site' to 'unicore'@'localhost';
GRANT ALL PRIVILEGES ON 'unicore_data_demo_site' to 'unicore'@'';

The UNICORE persistence properties would in this case look like this:

Table 13. Additional configuration for MySQL
property name default value description



MySQL table type to use

6.2. Clustering

If you intend to run a configuration with multiple UNICORE servers accessing a shared database, you need to enable clustering mode by setting a property


The clustering config file can be set using a (per-table) property

persistence.cluster.config=<path to config file>

If this is not set, a default configuration is used.

For clustering, the Hazelcast library is used ( A simple TCP based configuration is

        <port auto-increment="true">5701</port>
            <multicast enabled="false">
            <tcp-ip enabled="true">
        <interfaces enabled="false">
    <queue name="default">
    <map name="default">

The most important part is the "tcp-ip" setting, which must list at least one other node in the cluster. The "group" setting allows to run multiple clusters on the same set of hosts, just make sure that the group name is the same for all nodes in a cluster.

Most of the other settings (map, executor-service, etc) are currently not important, because only the distributed lock feature of Hazelcast is used. Please read the Hazelcast documentation for further information.

7. Configuring the XNJS

The XNJS is the UNICORE/X component that deals with the actual job execution and file access. It is configured using an XML file named xnjs.xml or xnjs_legacy.xml. The actual file that is used is set in the uas.config property uas.targetsystemfactory.xnjs.configfile.

# in uas.config

Here’s an overview of the most important properties that can be set in this file.

Table 14. Main XNJS properties
config file property name range of values default value description



an absolute path on the target system’s filesystem


the directory on the target system where job directories will be created


a path on the UNICORE/X machine


the directory on the UNICORE/X machine where the XNJS keeps its state


a file or directory name


the IDB containing application definitions etc.


an integer


the number of worker threads used to process jobs

Most of the other settings in this file are used to configure the internals of the XNJS and should usually be left at their default values.


This section describes installation and usage of the UNICORE TSI. This is a mandatory step if you want to interface to batch systems such as Torque, SGE, or LoadLeveller to efficiently use a compute cluster.


Without this component, all jobs will run on the UNICORE/X server, under the user id that started UNICORE/X.

In a nutshell, you have to perform the following steps

  • Install the UNICORE TSI on your cluster front end node

  • Edit the file

  • On the UNICORE/X server, edit uas.config, simpleidb and xnjs_legacy.xml

  • Start the newly installed TSI (as root in a multiuser setting)

  • Restart UNICORE/X

7.1.1. Installation of the correct TSI

The TSI is a set of perl modules that is running on the target system. In case of a cluster system, you’ll need to install it on the frontend machine(s), i.e. the machine from where your jobs are submitted to the batch system. There are different variants available for the different batch systems such as Torque or SGE.

Usually installation and start of the TSI will be performed as the root user. The TSI will then be able to change to the current Grid user’s id for performing work (Note: nothing will ever be executed as "root"). You can also use a normal user, but then all commands will be executed under this user’s id.

  • First, download and install the UNICORE TSI package. The UNICORE core server bundle ("quickstart" package) includes the TSI in the tsi subdirectory. You should copy this folder to the correct machine first. In the following this will be denoted by <tsidir>

  • Install the correct TSI variant by

 cd <tsidir>

When prompted for the path, choose an appropriate on, denoted <your_tsi> in the following

  • Check the tsi file in


especially command locations, path settings etc.

  • set permissions using

  cd <tsidir>
  • MAKE A NOTE of the exact location of the tsi_ls and tsi_df files <tsidir>/<your_tsi>/tsi_ls and <tsidir>/<your_tsi>/tsi_df

7.1.2. Required TSI Configuration

Configuration is done by editing <tsi_dir>/conf/ The following settings are needed:

#path to your tsi installation

#UNICORE/X machine
tsi.njs_machine=<UNICORE/X host>

#UNICORE/X listener port (check unicorex/conf/xnjs_legacy.xml variable "CLASSICTSI.replyport"

#TSI listener port (check unicorex/conf/xnjs_legacy.xml variable "CLASSICTSI.port"

7.1.3. UNICORE/X configuration

Edit unicorex/conf/uas.config and set the variable


Edit unicorex/conf/xnjs_legacy.xml. Check the filespace location, this is where the local job directories will be created. On a cluster, these have to be on a shared part of the filesystem.

Check the CLASSICTSI related properties. Set the correct value for the machine and the ports (these can usually be left at their default values)

Set the value of CLASSICTSI.TSI_LS to the path of tsi_ls as noted above.

Set the value of CLASSICTSI.TSI_DF to the path of tsi_df as noted above.

Here is an example section for the classic TSI properties.

    <eng:Property name="XNJS.tsiclass" value="de.fzj.unicore.xnjs.legacy.LegacyTSI"/>
    <!-- TSI machine and ports used -->
    <eng:Property name="CLASSICTSI.machine" value="localhost"/>
    <eng:Property name="CLASSICTSI.port" value="4433"/>
    <eng:Property name="CLASSICTSI.replyport" value="7654"/>
    <!-- location of the tsi_ls file -->
    <eng:Property name="CLASSICTSI.TSI_LS" value="tsi/tsi_ls"/>
    <!-- location of the tsi_df file -->
    <eng:Property name="CLASSICTSI.TSI_DF" value="tsi/tsi_df"/>
    <!-- commands on the target system -->
    <eng:Property name="CLASSICTSI.CP" value="/bin/cp"/>
    <eng:Property name="CLASSICTSI.RM" value="/bin/rm"/>
    <eng:Property name="CLASSICTSI.MV" value="/bin/mv"/>
    <eng:Property name="CLASSICTSI.MKDIR" value="/bin/mkdir -p"/>
    <eng:Property name="CLASSICTSI.CHMOD" value="/bin/chmod"/>
    <eng:Property name="CLASSICTSI.MKFIFO" value="/usr/bin/mkfifo"/>
    <eng:Property name="CLASSICTSI.PERL" value="/usr/bin/perl"/>
    <!-- interval between updates of job stati (milliseconds) -->
    <eng:Property name="CLASSICTSI.statusupdate.interval" value="5000"/>
    <!-- how often the XNJS will re-try to get the status of a job
         in case the job is not listed in the status listing -->
    <eng:Property name="CLASSICTSI.statusupdate.grace" value="0"/>
    <!-- a user that is allowed to see all jobs on the batch system -->
    <eng:Property name="CLASSICTSI.priveduser" value="someuser"/>
    <!-- I/O buffer size, will greatly impact filetransfer performance -->
    <eng:Property name="CLASSICTSI.BUFFERSIZE" value="1000000"/>

7.1.4. Additional parameters

Some additional parameters exist for tuning the XNJS-TSI communication.

Table 15. XNJS-TSI communication settings
property name range of values default value description




Buffersize for filetransfers in bytes




Socket timeout in milliseconds




Connection timeout in milliseconds

7.1.5. Tuning the batch system settings

UNICORE uses the normal batch system commands (e.g. qstat) to get the status of running jobs. There is a special case if a job is not listed in the qstat output. UNICORE will then assume the job is finished. However, in some cases this is not true, and UNICORE will have a wrong job status. To work around, there is a special property

    <!-- how often the XNJS will re-try to get the status of a job
         in case the job is not listed in the status listing -->
    <eng:Property name="CLASSICTSI.statusupdate.grace" value="2"/>

If the value is larger than zero, UNICORE will re-try to get the job status.

Start the TSI using (as root in a multiuser environment)

cd <tsi_dir>/conf

(or use the unicore-tsi init script if available in your installation)

Finally, restart the UNICORE/X server


When changing TSIs, it’s a good idea to remove the UNICORE/X state and any files before restarting. In the quickstart configuration, this is done using See the section on persistence for details

7.1.6. Enabling SSL for the XNJS to TSI communication

The UNICORE/X server can be set up to use SSL for communicating with the Perl TSI. On the UNICORE/X side, this is very simple to switch on. In the XNJS config file, add a line to the "Core" section:

    <!-- enable SSL using the normal UNICORE/X key and trusted certificates -->

On the TSI side it is a bit more complex, and you need to have the TSI from the 6.3.0 distribution or later installed. First of all, your Perl installation must include the module "IO::Socket:SSL" and its dependencies. If you do not have it, you can get it from the CPAN archive.

In the configuration file, you set the keystore and truststore to be used:

# SSL parameters
# Keystore must contain the private TSI key and certificate
# Trustore must contain the certificate of the CA

Both keystore and truststore are in pem format.

8. The IDB

The UNICORE IDB (incarnation database) contains information on how abstract job definitions are to be mapped onto real executables. This process (called "incarnation") is performed by the XNJS component. The second IDB function is advertising target system capabilities and allowing to check client resource requests against these.

The IDB is a (set of) XML files, which by default is called simpleidb.

For reference, the current XML schema for the IDB can be read from the SVN repository.

8.1. Defining the IDB file

The IDB file is defined by the property "XNJS.idbfile", which must point to a file on the UNICORE/X machine which is readable by the UNICORE/X process. For security reasons, it should NOT be writable.

8.2. Using an IDB directory

While the IDB can be put into a single file, it is often convenient to use multiple files. In this case, the property "XNJS.idbfile" points to a directory. This directory should contain

  • a single, mandatory, "main" IDB file

  • optionally, multiple XML files containing application definitions (see below)

  • optionally, multiple XML files containing execution environment definitions (see here)

The main IDB file consists of an "IDB" XML element:

<idb:IDB xmlns:idb="">

while application files use the Application element

<idb:IDBApplication xmlns:idb="">

and the execution environment files look like this:

<ee:ExecutionEnvironment xmlns:ee="">

8.3. Applications

The most important functionality of the IDB is providing executables for abstract applications. An abstract application is given by name and version, whereas an executable application is given in terms of executable, arguments and environment variables.

8.3.1. Simple applications

Here is an example entry for the "Date" application on a UNIX system

   <idb:IDBApplication xmlns:idb="">
    <jsdl:POSIXApplication xmlns:jsdl="">

As can be seen, "Date" is simply mapped to "/bin/date".

8.3.2. Arguments

Command line arguments are specified using <Argument> tags:

   <idb:IDBApplication xmlns:idb="">
    <jsdl:POSIXApplication xmlns:jsdl="">

This would result in a command line "/bin/ls -l -t".

8.3.3. Conditional Arguments

The job submission from a client usually contains environment variables to be set when running the application. It often happens that a certain argument should only be included if a corresponding environment variable is set. This can be achieved by using "conditional arguments" in the incarnation definition. Conditional arguments are indicated by a quastion mark "?" appended to the argument value:

    <jsdl:POSIXApplication xmlns:jsdl="">
      <!-- other args omitted for clarity -->

Here, <jsdl:Argument>-cp$CLASSPATH?</jsdl:Argument> is an optional argument.

If a job submission now includes a Environment variable named CLASSPATH

  <jsdl:Environment name="CLASSPATH">myjar.jar</jsdl:Environment>

the incarnated commandline will be "/usr/bin/java -cp$CLASSPATH …", otherwise just "/usr/bin/java …".

This allows very flexible incarnations.

8.3.4. More

For more details about IDB application definitions, please consult the detailed application definition guide.

8.4. TargetSystemProperties

The TargetSystemProperties element contains information about a site’s available resources, as well as additional information that should be published to clients.

8.4.1. Textual information

Simple strings can be entered into the IDB which are then accessible client-side. This is very useful for conveying system-specifics to client code and also to users. These text-info strings are entered into the IDB as a subtag of the TargetSystemProperties tag

Here is an example


    <!-- text infos -->
    <idb:Info Name="Administator email"></idb:Info>


These pieces of information are accessible client side as part of the target system properties.

8.4.2. Resources

Resources of a target system are specified using JSDLs Resource tag. It allows to specify things like number of nodes, CPUtime (per CPU), CPUs per node, total number of CPUs, etc.

These capabilities are specified giving an exact value and a range, for example:


The Range gives upper and lower bounds, where as the Exact value is interpreted as the DEFAULT, when the client does not request anything specific. If the Exact value is specified, the resource is part of the site’s default resource set.

There exist a number of standard settings. You may choose to not specify some of them, if they do not make sense on your system. For example, some sites do not allow the user to explicitely select nodes and processors per node, but only "total number of CPUs".

  • jsdl:IndividualCPUTime : The wall clock time.

  • jsdl:IndividualCPUCount : The number of CPUs per node

  • jsdl:IndividualPhysicalMemory : The amount of memory per node (in bytes)

  • jsdl:TotalResourceCount : The number of nodes.

  • jsdl:TotalCPUCount : The total number of CPUs.

8.4.3. "Total CPUs" vs. "Nodes and CPUs per node"

Users can specify the number of processors either as just "total number of CPUs", or they can give a value for both "nodes" and "CPUs per node". If both are given, the values containing more information (i.e. nodes + CPUs per node) are used.

Similarly, if the administrator specifies both possibilities with a default value in the IDB, the nodes + CPUs per node will have precedence.

8.4.4. Other types of resources

Most HPC sites have special settings that cannot be mapped to the generic JSDL elements shown in the previous section. Therefore UNICORE 6 includes a mechanism to allow sites to specify their own system settings and allow users to set these using the Grid middleware.

Custom resources are described in this section.

8.4.5. Example Resources section

This example includes the elements defining capabilities, and some informational elements like CPUArchitecture and operating system info.

    <jsdl:Resources xmlns:jsdl="">

        <!-- O/S -->
       <jsdl:Description>A free UNIX clone</jsdl:Description>

      <!-- cpu time (per cpu) in seconds -->

      <!-- Nodes -->

      <!-- CPUs per node -->

      <!-- total CPUs -->

      <!-- Memory per node (bytes) -->


8.5. Script templates

If you need to modify the scripts that are generated by UNICORE/X and sent to the TSI, you can achieve this using two entries in the IDB.

<idb:IDB xmlns:idb="">

<!-- Templates -->


<!-- rest of IDB omitted -->


The SubmitScriptTemplate is used for batch job submission, the ExecuteScriptTemplate is used for everything else (e.g. creating directories, resolving user’s home, etc)

UNICORE/X generates the TSI script as follows:

  • the "#COMMAND" entry will be replaced by the action for the TSI, e.g. "#TSI_SUBMIT".

  • the "#RESOURCES" will be replaced by the resource requirements, e.g. "#TSI_NODES=…"

  • the "#SCRIPT" is the user script

Modifying these templates can be used to perform special actions, such as loading modules, or changing the shell (but use something compatible to sh). For example, to add some special directory to the path for user scripts submitted in batch mode, you could use

<idb:IDB xmlns:idb="">

<!-- Templates -->
PATH=$PATH:/opt/openmpi-2.1/bin; export PATH

<!-- rest of IDB omitted -->


8.5.1. Properties

In the IDB file, XNJS properties can be specified, for example the command locations identified by property names starting with "CLASSICTSI."

<idb:IDB xmlns:idb="">
<!--- rest of IDB omitted -->
 <idb:Property name="..."

8.6. More on the IDB Application definitions

Simple application definitions and application arguments have already been covered in the previous section. Here, more details are presented.

8.6.1. Pre and post-commands

Sometimes it is useful to be able to execute one or several commands before or after the execution of an application. For example, to add directories to the path, or perform some pre-processing. The IDB allows to specify these using the PreCommand and PostCommand tags.

For example

    <jsdl:POSIXApplication xmlns:jsdl="">
      <!-- other args omitted for clarity -->
    <idb:PreCommand>PATH=$PATH:/opt/myapp/bin ; export PATH</idb:PreCommand>

These commands will be executed as part of the user’s job script.

8.6.2. Interactive execution when using a batch system

If an application should not be submitted to the batch system, but be run on the login node (i.e. interactively), a flag in the IDB can be set:


    <!-- instructs TSI to run the application interactively -->

    <jsdl:POSIXApplication xmlns:jsdl="">
      <!-- other args omitted for clarity -->

This should only be used for very short-running tasks, since UNICORE cannot track the status of such a task. It is simply forked by the TSI, and UNICORE will just assume it is finished after a short while.

8.7. Application metadata (simple)

For client components it is very useful to have a description of an application in terms of its arguments. This allows for example the "Generic" GridBean in the UNICORE Rich client to automatically build a nice GUI for the application.

You can optionally attach metadata to an applications arguments.

  <jsdl:Argument Description="Verbose Execution"
                 ValidValues="true false"

Some metadata is inferred automatically, such as the argument name (VERBOSE in the example above).

The meaning of the attributes should be fairly obvious.

  • the Description attribute contains a human-readable description of the argument

  • the Type attribute can have the values "string", "boolean", "int", "double", "filename" or "choice". In the case of "choice", the ValidValues attribute is used to specify the list of valid values. The type filename is used to specify that this is an input file for the application, allowing clients to enable special actions for this.

  • The MimeType attribute allows to specify the mime-types of an input or output file as a comma-separated list. This can be used by smart clients, for example to check the viability of workflows.

  • The ValidValues attribute is used to limit the range of valid values, depending on the Type of the argument. The processing of this attribute is client-dependent. The UNICORE Rich Client supports intervals for the numeric types, and Java regular expressions for the string types.

  • DependsOn and Excludes are space-separated lists of argument names to control dependencies. For example, a "VERBOSE and a "QUIET" attribute should exclude each other.

  • IsMandatory (values: true or false) specifies if a parameter MUST be provided.

  • IsEnabled (values: true or false) is intended to tell clients that the parameter should initially be enabled in the GUI.

8.7.1. Application metadata (complex)

You can also add metadata as XML to the IDB entry, which allows you to add your custom metadata:

Currently the XML metadata only encompass argument metadata, similar to the "simple" metadata described above. However, custom metadata can be added in case an application requires it.

Here is a simple example.


    <!-- metadata -->
    <u6:Metadata xmlns:u6="">
      <!-- example argument-->
          <u6:Description>Precision of the computation</u6:Description>
      <!-- any custom XML can be added as well -->
      <!-- ... -->

The XML supports the Type, Description, MimeType, IsMandatory, DependsOn, Excludes and ValidValue elements, with the same semantics as described above.

8.8. Execution Environments

Execution environments are an advanced feature that allows you to configure the way an executable is executed in a more detailed and user-friendly fashion. A common scenario is the configuration of an environment for parallel execution of a program, such as MPI.

A typical simple MPI invocation looks like this

/usr/local/bin/openmpi -np 4 ./my_mpi_program [my_program_arguments]

but of course there are many more possible arguments to the MPI command, which also depend on the local installation. By using a predefined execution environment, a UNICORE user need not know all the details, but can set up her job in a simple fashion.

This document covers the options that are available to configure execution environments in the IDB.

  • XML Schema for the execution environments: the current XML schema for the execution environment specification can be read from the SVN repository.

8.9. IDB definition of execution environments

The server-side setup of an execution environment is by adding an XML entry into the IDB. A simple environment might be used to run a user command using time. This example shows every possible option. You might want to consult the man page of time.

<idb:IDB xmlns:idb="">

<!-- sample execution environment definition in the IDB -->
  <ee:ExecutionEnvironment xmlns:ee="">
    <ee:Description>Runs the user's command using the 'time' tool, measuring the used CPU time.</ee:Description>
    <ee:CommandlineTemplate>#EXECUTABLE #ARGS #USERCOMMAND #USERARGS</ee:CommandlineTemplate>
        <ee:Description>Write the resource use statistics to a FILE instead of to the standard error stream</ee:Description>
        <ee:Description>Enable verbose mode</ee:Description>
      <ee:IncarnatedValue>echo "Started at $(date)"</ee:IncarnatedValue>
        <ee:Description>Explicitely print the start time</ee:Description>
      <ee:IncarnatedValue>echo "Finished at $(date)"</ee:IncarnatedValue>
        <ee:Description>Explicitely print the finishing time</ee:Description>


If a client now submits a job including a request for the "TIME" execution environment, UNICORE will generate a shell script that wraps the user command in the "time" invocation. Let’s say the job request includes the "Output" argument, the "Verbose" option and both precommand and postcommand:

  <!-- sample execution environment request sent from client to server -->
  <ee:ExecutionEnvironment xmlns:ee="">

The script generated by UNICORE will look like this (leaving out some standard things):


# ...

echo "Started at $(date)"
/usr/bin/time -o time_profile -v /path/to/my_user_application
echo "Finished at $(date)"

# ...

In the following the various XML tags that are available are explained in detail.

  • ExecutableName : This is the name of the executable that "defines" the environment.

  • CommandlineTemplate : To control the exact commandline that is created, this template is used.

The default template is



  • #EXECUTABLE is the executable defined using ExecutableName

  • #ARGS are the arguments and options for the executable

  • #USERCOMMAND is the user’s executable

  • #USERARGS are the arguments to the user’s executable

  • Argument : the Argument elements are used to create arguments to the executable. They have several subtags.

  • Name is the name of the argument.

  • IncarnatedValue is the argument as used in the commandline.

  • ArgumentMetadata are described below.

  • ArgumentMetadata : This element allows to describe an Argument in more detail. It has the following subtags

  • Type the argument type. Valid values are "string", "boolean", "int", "float" and "choice"

  • Description is a human-friendly description

  • Default a possible default value

  • ValidValue tags are used to denote possible values

  • DependsOn denotes other arguments that this argument requires

  • Excludes denotes other arguments that clash with this argument

  • PreCommand : This tag denotes a command that is executed immediately before the actual executable. Its subtags are the same as for Option.

  • PostCommand : This tag denotes a command that is executed after the actual execution. Its subtags are the same as for PreCommand.

8.10. Custom resource definitions

Most sites (especially in HPC) have special settings that cannot be mapped to the generic JSDL elements shown in the previous section. Therefore UNICORE 6 includes a mechanism to allow sites to specify their own system settings and allow users to set these using the Grid middleware.

This requires two things

  • Custom resource definitions in the IDB

  • Customisation of the TSI module

If this mechanism is not flexible enough for your needs, consider looking at dynamic incarnation which is described here.

8.10.1. The IDB

You can insert <Resource> elements into the Resources section, an example follows.


    <idb:Resource xmlns:idb="">
      <idb:Description>The number of tasks per node. If larger than 32, the node will run in SMT mode.</idb:Description>


Apart from the numeric types <int> or <double>, there are the <string>, <choice> and <boolean> types. The <choice> allows you to specify a set of allowed values. This is useful for example to specify a selection of batch queues, or a selection of network topologies.

For example, defining queues could look like this:


    <idb:Resource xmlns:idb="">
      <idb:Description>The batch queue to use</idb:Description>


This example defines four available queues, with the "normal" one being used by default.


The resource name "Queue" is recognized automatically by UNICORE and mapped to the correct TSI_QUEUE parameter when sending the job to the TSI.

8.10.2. Submitted JSDL

Clients can now send a special element in the JSDL job, for example requesting a certain value for the "TasksPerNode" setting:


          <jsdl-u:ResourceRequest xmlns:jsdl-u="">


or for the queue example:


          <jsdl-u:ResourceRequest xmlns:jsdl-u="">


8.10.3. TSI request

The UNICORE/X server will send the following snippet to the TSI:

# ...
# ....

As you can see, a special TSI command tag "#TSI_SSR_TASKSPERNODE" has been added. Now the remaining step is to have the TSI module has to parse this properly, and generate the correct batch system command.

8.11. Tweaking the incarnation process

In UNICORE the term incarnation refers to the process of changing the abstract and probably universal grid request into a sequence of operations local to the target system. The most fundamental part of this process is creation of the execution script which is invoked on the target system (usually via a batch queuing subsystem (BSS)) along with an execution context which includes local user id, group, BSS specific resource limits.

UNICORE provides a flexible incarnation model - most of the magic is done automatically by TSI scripts basing on configuration which is read from the IDB. IDB covers script creation (using templates, abstract application names etc). Mapping of the grid user to the local user is done by using UNICORE Attribute Sources like XUUDB or UVOS.

In rare cases the standard UNICORE incarnation mechanism is not flexible enough. Typically this happens when the script which is sent to TSI should be tweaked in accordance to some runtime constraints. Few examples may include:

  • Administrator wants to set memory requirements for all invocations of the application X to 500MB if user requested lower amount of memory (as the administrator knows that the application consumes always at least this amount of memory).

  • Administrator wants to perform custom logging of suspected requests (which for instance exceed certain resource requirements threshold)

  • Administrator need to invoke a script that create a local user’s account if it doesn’t exist.

  • Administrator wants to reroute some requests to a specific BSS queue basing on the arbitrary contents of the request.

  • Administrator wants to set certain flags in the script which is sent to TSI when a request came from the member of a specific VO. Later those flags are consumed by TSI and are used as submission parameters.

Those and all similar actions can be performed with the Incarnation tweaking subsystem. Note that though it is an extremely powerful mechanism, it is also a very complicated one and configuring it is error prone. Therefore always try to use the standard UNICORE features (like configuration of IDB and attribute sources) in the first place. Treat this incarnation tweaking subsystem as the last resort!

To properly configure this mechanism at least a very basic Java programming language familiarity is required. Also remember that in case of any problems contacting the UNICORE support mailing list can be the solution.

8.11.1. Operation

It is possible to influence incarnation in two ways:

  • BEFORE-SCRIPT it is possible to change all UNICORE variables which are used to produce the final TSI script just before it is created and

  • AFTER-SCRIPT later on to change the whole TSI script.

The first BEFORE-SCRIPT option is suggested: it is much easier as you have to modify some properties only. In the latter much more error prone version you can produce an entirely new script or just change few lines of the script which was created automatically. It is also possible to use both solutions simultaneously.

Both approaches are configured in a very similar way by defining rules. Each rule has its condition which triggers it and list of actions which are invoked if the condition was evaluated to true. The condition is in both cases expressed in the same way. The difference is in case of actions. Actions for BEFORE-SCRIPT rules can modify the incarnation variables but do not return a value. Actions for AFTER-SCRIPT read as its input the original TSI script and must write out the updated version. Theoretically AFTER-SCRIPT actions can also modify the incarnation variables but this doesn’t make sense as those variables won’t be used.

8.11.2. Basic configuration

By default the subsystem is turned off. To enable it you must perform two simple things:

  • Add the XNJS.incarnationTweakerConfig property to the XNJS config file. The value of the property must provide a location of the file with dynamic incarnation rules.

  • Add some rules to the file configured above.

The following example shows how to set the configuration file to the value conf/incarnationTweaker.xml:

    <eng:Property name="XNJS.incarnationTweakerConfig" value="conf/incarnationTweaker.xml"/>

The contents of the rules configuration file must be created following this syntax:

<?xml version="1.0" encoding="UTF-8"?>
<tns:incarnationTweaker xmlns:tns="http://eu.unicore/xnjs/incarnationTweaker"

                <!-- Here come BEFORE-SCRIPT rules-->

                <!-- And here AFTER-SCRIPT rules-->

8.11.3. Creating rules

Each rule must conform to the following syntax:

        <tns:rule finishOnHit="false">
                <tns:condition> <!-- Here comes the rule's condition --> </tns:condition>

                <tns:action type="ACTION-TYPE">ACTION-DEFINITION</tns:action>
                <!-- More actions may follow -->

The rule’s attribute finishOnHit is optional, by default its value is false. When it is present and set to true then this rule becomes the last rule invoked if it’s condition was met.

You can use as many actions as you want (assuming that at least one is present), actions are invoked in the order of appearance.

SpEL and Groovy

Rule conditions are always boolean expressions of the Spring Expression Language (SpEL). As SpEL can be also used in some types of actions it is the most fundamental tool to understand.

Actions can be also coded using the Groovy language. You can find Groovy documentation at Groovy’s web page:

Creating conditions

Rule conditions are always Spring Expression Language (SpEL) boolean expressions. To create SpEL expressions, the access to the request-related variables must be provided. All variables which are available for conditions are explained in the dynamic incarnation context section.

Creating BEFORE-SCRIPT actions

There are the following action types which you can use:

  • spel (the default which is used when type parameter is not specified) treats action value as SpEL expression which is simply evaluated. This is useful for simple actions that should modify value of one variable.

  • script treats action value as a SpEL expression which is evaluated and which should return a string. Evaluation is done using SpEL templating feature with \${ and } used as variable delimiters (see section 7.5.13 in Spring documentation for details). The returned string is used as a command line which is invoked. This action is extremely useful if you want to run an external program with some arguments which are determined at runtime. Note that if you want to cite some values that may contain spaces (to treat them as a single program argument) you can put them between double quotes ". Also escaping characters with "\" works.

  • groovy treats action value as a Groovy script. The script is simply invoked and can manipulate the variables.

  • groovy-file works similarly to the groovy action but the Groovy script is read from the file given as the action value.

All actions have access to the same variables as conditions; see the dynamic incarnation context section for details.

Creating AFTER-SCRIPT actions

There are the following action types which you can use:

  • script (the default which is used when type parameter is not specified) treats action value as SpEL expression which is evaluated and which should return a string. Evaluation is done using SpEL templating feature with \${ and } used as variable delimiters (see section 7.5.13 in Spring documentation for details). The returned string used as a command line which is invoked. The invoked application gets as its standard input the automatically created TSI script and is supposed to return (using standard output) the updated script which shall be used instead. This action is extremely useful if you want to run an external program with some arguments which are determined at runtime. Note that if you want to cite some values that may contain spaces (to treat them as a single program argument) you can put them between double quotes ". Also escaping characters with \ works.

  • groovy treats action value as a Groovy script. The script has access to one special variable input of type Reader. The original TSI script is available from this reader. The groovy script is expected to print the updated TSI script which shall be used instead of the original one.

  • groovy-file works the same as the groovy action but the Groovy script is read from the file given as the action value.

All actions have access to the same variables as conditions; see the section on dynamic incarnation context for details.

8.11.4. Final notes

  • The rules configuration file is automatically reread at runtime.

  • If errors are detected in the rules configuration file upon server startup then the whole subsystem is disabled. If errors are detected at runtime after an update then old version of rules is continued to be used. Always check the log file!

  • When rules are read the system tries to perform a dry run using an absolutely minimal execution context. This can detect some problems in your rules but mostly only in conditions. Actions connected to conditions which are not met won’t be invoked. Always try to submit a real request to trigger your new rules!

  • Be careful when writing conditions: it is possible to change incarnation variables inside your condition - such changes also influence incarnation.

8.11.5. Complete examples and hints

Invoking a logging script for users who have the specialOne role. Note that the script is invoked with two arguments (role name and client’s DN). As the latter argument may contain spaces we surround it with quotation marks.

<?xml version="1.0" encoding="UTF-8"?>
<tns:incarnationTweaker xmlns:tns="http://eu.unicore/xnjs/incarnationTweaker"

                        <tns:condition> == "specialOne"</tns:condition>
                        <tns:action type="script">/opt/scripts/ ${} "${client.distinguishedName}"</tns:action>


A more complex example. Let’s implement the following rules:

  • The Application with a IDB name HEAVY-APP will always get 500MB of memory requirement if user requested less or nothing.

  • All invocations of an executable /usr/bin/serial-app are made serial, i.e. the number of requested nodes and CPUs are set to 1.

  • For all requests a special script is called which can create a local account if needed along with appropriate groups.

  • There is also one AFTER-RULE. It invokes a groovy script which adds an additional line to the TSI script just after the first line. The line is added for all invocations of the /usr/bin/serial-app program.

The realization of the above logic can be written as follows:

<?xml version="1.0" encoding="UTF-8"?>
<tns:incarnationTweaker xmlns:tns="http://eu.unicore/xnjs/incarnationTweaker"

                        <tns:condition>app.applicationName == "HEAVY-APP" and (resources.individualPhysicalMemory == null
                                          or resources.individualPhysicalMemory &lt; 500000000)</tns:condition>
                        <tns:condition>app.executable == "/usr/bin/serial-app" and resources.individualCPUCount != null</tns:condition>
                        <tns:action type="script">/opt/ ${client.xlogin.userName} ${client.xlogin.encodedGroups}</tns:action>

                        <tns:condition>app.executable == "/usr/bin/serial-app"</tns:condition>
                        <tns:action type="groovy">
int i=0;
input.eachLine() { line ->
if(i==1) {
} else


Remember that some characters are special in XML (e.g. < and &). You have to encode them with XML entities (e.g. as &lt; and &gt; respectively) or put the whole text in a CDATA section. A CDATA section starts with "<![CDATA[" and ends with "]]>". Example:

<tns:condition><!CDATA[ resources.individualPhysicalMemory < 500000000 ]]></tns:condition>

Note that usually it is better to put Groovy scripts in a separate file. Assuming that you placed the contents of the groovy AFTER-action above in a file called /opt/scripts/filter1.g then the following AFTER-SCRIPT section is equivalent to the above one:

                        <tns:condition>app.executable == "/usr/bin/serial-app"</tns:condition>
                        <tns:action type="groovy-file">/opt/scripts/filter1.g</tns:action>

To check your rules when you develop them, it might be wise to enable DEBUG logging on incarnation tweaker facility. To do so add the following setting to the file:


You may also want to see how the final TSI script looks like. Most often TSI places it in a file in job’s directory. However if the TSI you use doesn’t do so (e.g. in case of the NOBATCH TSI) you can trigger logging of the TSI script on the XNJS side. There are two ways to do it. You can enable DEBUG logging on the unicore.xnjs.tsi.TSIConnection facility:


This solution is easy but it will produce also much more of additional information in you log file. If you want to log TSI scripts only, you can use AFTER-SCRIPT rule as follows:

                        <tns:action type="groovy">
org.apache.log4j.Logger log=org.apache.log4j.Logger.getLogger("unicore.xnjs.RequestLogging");"Dumping TSI request:");
input.eachLine() { line ->
     println(line);"  " + line);

The above rule logs all requests to the normal Unicore/X log file with the INFO level.

8.12. Incarnation tweaking context

Dynamic incarnation tweaker conditions and also all actions are provided with access to all relevant data structures which are available at XNJS during incarnation.

The following variables are present:

  • Client client provides access to authorization material: xlogin, roles, attributes etc. NOTE: In general it makes sense to modify only the xlogin field in the Client object, the rest are available only for information purposes. E.g. there is a queue field, but changing it in the incarnation tweaker rules will have no effect on incarnation. Use the queue property available from resources variable instead. You can read client’s queue to check what queue settings were defined in attribute sources for the user. The source

  • ApplicationInfo app provides access to information about application to be executed (both abstract IDB name and actual target system executable). You can change the values here to influence the incarnation. Remember that changing the user’s DN here won’t influence authorization layer as authorization was already done for each request at this stage. The source

  • ResourcesWrapper resources provides access to resource requirements of the application. The source

  • ExecutionContext ec provides access to the application environment: interactive setting, environment variables, working directory and stdin/out/err files. The source

  • IncarnatedExecutionEnvironment execEnv provides access to the template which is used to produce the final script. In most cases only manipulating pre- and post- commands makes sense. The source

  • IncarnationDataBase idb provides an (read only) access to the contents of the IDB. The source

Each of the available variables has many properties that you can access. It is best to check source code of the class to get a complete list of them. You can read property X if it has a corresponding Java public Type getX() method. You can set a property Y if it has a corresponding Java public void setY(Type value) method.

8.12.1. Simple example

Let’s consider the variable client. In the Client class you can find methods:

public String getDistinguishedName()

public void setDistinguishedName(String distinguishedName)

This means that the following SpEL condition is correct:

client.distinguishedName != null and client.distinguishedName == "CN=Roger Zelazny,C=US"

Note that it is always a safe bet to check first if the value of a property is not null.

Moreover you can also set the value of the distinguished name in an action (this example is correct for both SpEL and Groovy):

client.distinguishedName="CN=Roger Zelazny,C=US"

8.12.2. Advanced example

Often the interesting property is not available directly under one of the above enumerated variables. In case of the client variable one example may be the xlogin property holding the list of available local accounts and groups and the ones which were selected among them.

Example of condition checking the local user id:

client.xlogin.userName != null and client.xlogin.userName == "roger"

Setting can also be done in an analogous way. However always pay attention to the fact that not always setting a value will succeed. E.g. for Xlogin it is possible to set a selected xlogin only to one of those defined as available (see contents if the respective setSelectedLogin() method). Therefore to change local login to a fixed value it is best to just override the whole XLogin object like this (SpEL):

client.xlogin=new String[] {"roger"}, new String{"users"})

8.12.3. Resources variable

As it is bit difficult to manipulate the resources requirements object which is natively used by UNICORE, it is wrapped to provide an easier to use interface. The only exposed properties are those requirements which are actually used by UNICORE when the TSI script is created.

You can access the low level (and complicated) original resources object through the resources.allResources property.

9. The UNICORE metadata service

UNICORE supports metadata management on a per-storage basis. This means, each storage instance (for example, the user’s home, or a job working directory) has its own metadata management service instance.

Metadata management is separated into two parts: a front end (which is a web service) and a back end.

The front end service allows the user to manipulate and query metadata, as well as manually trigger the metadata extraction process. The back end is the actual implementation of the metadata management, which is pluggable and can be exchanged by custom implementations. The default implementation has the following properties

  • Apache Lucene for indexing,

  • Apache Tika for extracting metadata,

  • metadata is stored as files directly on the storage resource, in files with a special ".metadata" suffix

  • the index files are stored on the UNICORE/X server, in a configurable directory

9.1. Enabling the metadata service

First, UNICORE’s service configuration file <CONF>/wsrflite.xml needs to be edited and the following service definition added in the <services> section:

 <!-- enable the metadata management service -->
 <service name="MetadataManagement" wsrf="true" persistent="true">
  <interface class="de.fzj.unicore.uas.MetadataManagement"/>
  <implementation class="de.fzj.unicore.uas.metadata.MetadataManagementHomeImpl"/>

You will also need to define which implementation should be used. This is done via properties, which can be defined either in <CONF>/wsrflite.xml or <CONF>/uas.config.

In uas.config, set:

# Metadata manager settings


# use Tika for extracting metadata
# (if you do not want this, remove this property)

# Lucene index directory:
# Configure a directory on the UNICORE/X machine where index
# files should be placed

9.2. Configuring the metadata service

No options currently. Future options will include

  • disabling metadata management on storages

  • configuring auto-extraction of metadata

10. Authorization back-end (PDP) guide

The authorization process in UNICORE/X requires that nearly all operations must be authorized prior to execution (exceptions may be safely ignored).

UNICORE allows to choose which authorization back-end is used. The module which is responsible for this operation is called Policy Decision Point (PDP). You can choose one among already available PDP modules or even develop your own engine.

Local PDPs use a set of policy files to reach an authorisation decision, remote PDPs query a remote service.

Local UNICORE PDPs use the XACML language to express the authorization policy. The XACML policy language is introduced in the Guide to XACML security policies. You can also review this guide if you want to have a deeper understanding of the authorization process.

10.1. Basic configuration

There are three options in the uas.config file which are relevant to all PDPs:

  • (values: true or false) This boolean property can be used to completely turn off the authorization. This guide makes sense only if this option is set to true. Except for test scenarios this should never be switched off, otherwise every user can in principle access all resources on the server.

  • (value: full class name) This property is used to choose which PDP module is being used.

  • (value: file path) This property provides a location of a configuration file of the selected PDP.

10.2. Available PDP modules

10.2.1. XACML 2.0 PDP

The implementation class of this module is: eu.unicore.uas.pdp.local.LocalHerasafPDP so to enable this module use the following configuration in uas.config:<CONFIG_DIR>/xacml2.conf

The configuration file content is very simplistic as it is enough to define only few options:

# The directory where XACML 2.0 policy files are stored

# Wildcard expression to select actual policy files from the directory defined above

# Combining algorithm for the policies. You can use the full XACML id or its last part.

The policies from the are always evaluated in alphabetical order, so it is good to name files with a number. By default the first-applicable combining algorithm is used and UNICORE policy is stored in two files: 01coreServices.xml and 99finalDeny.xml. The first file contains the default access policy, the latter a single fall through deny rule. Therefore you can put your own policies using an additional file in file named e.g. 50localRules.xml.

The policies are reloaded whenever you change (or touch) the configuration file of this PDP, e.g. like this:

touch conf/xacml2.conf

10.2.2. XACML 1.x PDP

The implementation class of this module is: eu.unicore.uas.pdp.localsun.LocalSunPDP so to enable this module use the following configuration in uas.config:

This module is the one that was the only available option in UNICORE prior to release 6.4.0

The rules are contained in one or more policy files as listed in the xacml.config configuration file. However note that in case of this legacy implementation it mostly doesn’t make sense to use more then one file as it not possible to control the combining algorithm (which would be only-one-applicable). Therefore the configuration file is rather absolutely constant:

<?xml version="1.0" encoding="UTF-8"?>
<config xmlns=""
        defaultPDP="pdp" defaultAttributeFactory="attr"
        defaultCombiningAlgFactory="comb" defaultFunctionFactory="func">
  <pdp name="pdp">
    <attributeFinderModule class="com.sun.xacml.finder.impl.CurrentEnvModule"/>
    <attributeFinderModule class="com.sun.xacml.finder.impl.SelectorModule"/>
    <policyFinderModule class="com.sun.xacml.finder.impl.FilePolicyModule">
  <attributeFactory name="attr" useStandardDatatypes="true"/>
  <combiningAlgFactory name="comb" useStandardAlgorithms="true"/>
  <functionFactory name="func" useStandardFunctions="true">


In case you modified the policy file(s), you can force a reload into the running server by "touch"ing the xacml.conf configuration file. For example, under Unix you can execute

touch conf/xacml.conf

Opening the file in an editor and saving it will also do the trick.

10.2.3. Remote SAML/XACML 2.0 PDP (Argus PDP)

This PDP allows for outsourcing authorization decision to the remote PDP service. Typically the Argus PDP is used for this purpose but in principle any PDP which implements the SAML XAML Authorization Query Protocol can be used.

The implementation class of this module is: eu.unicore.uas.pdp.argus.ArgusPDP so to enable this module use the following configuration in uas.config:<CONFIG_DIR>/argus.config

The PDP configuration is very simple as it is only required to provide the Argus endpoint and query timeout (in milliseconds).


You can use both http and https addresses. In the latter case server’s certificate is used to make the connection.

If the remote PDP can not be contacted due to any reason the authorization decision is always deny.

11. Guide to XACML security policies

XACML authorization policies need not to be modified on a day-to-day basis when running the UNICORE server. The most common tasks as banning or allowing users can be performed very easily using UNICORE Attribute Sources like XUUDB or UVOS. This guide is intended for advanced administrators who want to change the non-standard authorization process and for developers who want to provide authorization policies for services they create.

The XACML standard is a powerful way to express fine grained access control. The idea is to have XML policies describing how and by whom actions on resources can be performed. A very readable introduction into XACML can be found with Sun’s XACML implementation.

There are several versions of XACML policy language. Currently UNICORE supports both 1.x and 2.0 versions. Those are quite similar and use same concepts, however note that syntax is a bit different. In this guide we provide examples using XACML 2.0. The same examples in the legacy XACML 1.1 format are available below.

UNICORE allows to choose one of several authorization back-end implementations called Policy Decision Points (PDP). Among others you can decide whether to use local XACML 1.x policies or local XACML 2.0 policies. The authorization section shows how to choose and configure each of the available PDPs.

In UNICORE terms XACML is used as follows. Before each operation (i.e. execution of a web service call), an XACML request is generated, which currently includes the following attributes:

  • the name of the service being accessed (e.g. JobManagementService)

  • the name of the method being invoked (used as the "action" in XACML terms)

  • the distinguished name of the user making the request

  • the role of the user as retrieved from an attribute source (XUUDB/UVOS/…)

The request is processed by the server and checked against a (set of) policies. Policies contain rules that can either deny or permit a request, using a powerful set of functions.

11.1. Policy sets and combining of results

Typically, the authorization policy is stored in one file. However as this file can get long and unmanageable sometimes it is better to split it into several ones. This additionally allows to easily plug additional policies to the existing authorization process. In UNICORE, this feature is implemented in the XAML 2.0 PDP.

When policies are split in multiple files each of those files must contain (at least one) a separate policy. A PDP must somehow combine result of evaluation of multiple policies. This is done by so-called policy combining algorithm. The following algorithms are available, the part after last colon describes behaviour of each:


Each policy file can contain one or more rules, so it is important to understand how possible conflicts are resolved. The so-called combining algorithm for the rules in a single policy file is specified in the top-level Policy element.

The XACML (from version 1.1 onwards) specification defines six algorithms: permit-overrides, deny-overrides, first-applicable, only-one-applicable, ordered-permit-overrides and ordered-deny-overrides. For example, to specify that the first matching rule in the policy file is used to make the decision, the Policy element must contain the following "RuleCombiningAlgId" attribute:

<Policy xmlns="urn:oasis:names:tc:xacml:2.0:policy:schema:os"

The full identifiers of the combining algorithms are as follows:


11.2. Role-based access to services

A common use case is to allow/permit access to a certain service based on a user’s role This can be achieved with the following XACML rule, which describes that a user with role "admin" is given access to all service.

<Rule RuleId="Permit:Admin" Effect="Permit">
        <Description> Role "admin" may do anything. </Description>
        <Target />
          <Apply FunctionId="urn:oasis:names:tc:xacml:1.0:function:string-equal">
            <Apply FunctionId="urn:oasis:names:tc:xacml:1.0:function:string-one-and-only">
                    DataType="" AttributeId="role" />
            <AttributeValue DataType="">admin</AttributeValue>

If the access should be limited to a certain service, the Target element must contain a service identifier, as follows. In this example, access to the DataService is granted to those who have the data-access role.

<Rule RuleId="rule2" Effect="Permit">
        <Description>Allow users with role "data-access" access to the DataService</Description>
              <ResourceMatch MatchId="urn:oasis:names:tc:xacml:1.0:function:anyURI-equal">
                <AttributeValue DataType="">DataService</AttributeValue>
                <ResourceAttributeDesignator AttributeId="urn:oasis:names:tc:xacml:1.0:resource:resource-id"
                                             DataType="" MustBePresent="true" />

          <Apply FunctionId="urn:oasis:names:tc:xacml:1.0:function:string-equal">
            <Apply FunctionId="urn:oasis:names:tc:xacml:1.0:function:string-one-and-only">
              <SubjectAttributeDesignator DataType="" AttributeId="role" />
           <AttributeValue DataType="">data-access</AttributeValue>

By using the <Action> tag in policies, web service access can be controlled on the method level. In principle, XACML supports even control based on the content of some XML document, such as the incoming SOAP request. However this is not yet used in UNICORE/X.

11.3. Limiting access to services to the service instance owner

Most service instances (corresponding e.g. to jobs, or files) should only ever be accessed by their owner. This rule is expressed as follows

<Rule RuleId="Permit:AnyResource_for_its_owner" Effect="Permit">
        <Description> Access to any resource is granted for its owner </Description>
        <Target />
          <Apply FunctionId="urn:oasis:names:tc:xacml:1.0:function:x500Name-equal">
            <Apply FunctionId="urn:oasis:names:tc:xacml:1.0:function:x500Name-one-and-only">
              <SubjectAttributeDesignator AttributeId="urn:oasis:names:tc:xacml:1.0:subject:subject-id"
                                          MustBePresent="true" />
            <Apply FunctionId="urn:oasis:names:tc:xacml:1.0:function:x500Name-one-and-only">
                AttributeId="owner" DataType="urn:oasis:names:tc:xacml:1.0:data-type:x500Name"
                MustBePresent="true" />

11.4. More details on XACML use in UNICORE/X

To get more detailed information about XACML policies (e.g. to get the list of all available functions etc) consult the XACML specification. To get more information on XACML use in UNICORE/X it is good to set the logging level of security messages to DEBUG:

You will be able to read what input is given to the XACML engine and what is the detailed answer. Alternatively, ask on the support mailing list.

11.5. Policy examples in XACML 1.1 syntax

This section contains the same examples as are contained in the previous section, but using XACML 1.x syntax. For more detailed discussion of each example please refer to the previous section.

Policy header with first-applicable combining algorithm.

<Policy xmlns="urn:oasis:names:tc:xacml:1.0:policy"

A user with role "admin" is given access to all service.

<Rule RuleId="rule1" Effect="Permit">
 <Description>Allow users with role "admin" access to any service</Description>
 <Condition FunctionId="urn:oasis:names:tc:xacml:1.0:function:string-equal">
   <Apply FunctionId="urn:oasis:names:tc:xacml:1.0:function:string-one-and-only">
     <SubjectAttributeDesignator DataType="" AttributeId="role" />
   <!-- here is the role value -->
   <AttributeValue DataType="">admin</AttributeValue>

Defining which resource access is defined with the Target element:

<Rule RuleId="rule2" Effect="Permit">
 <Description>Allow users with role "data-access" access to the DataService</Description>
       <!-- specify the data service -->
        <ResourceMatch MatchId="urn:oasis:names:tc:xacml:1.0:function:anyURI-equal">
          <AttributeValue DataType="">DataService</AttributeValue>
          <ResourceAttributeDesignator DataType=""
 <Condition FunctionId="urn:oasis:names:tc:xacml:1.0:function:string-equal">
   <Apply FunctionId="urn:oasis:names:tc:xacml:1.0:function:string-one-and-only">
     <SubjectAttributeDesignator DataType="" AttributeId="role" />
   <!-- here is the role value -->
   <AttributeValue DataType="">data-access</AttributeValue>

Allowing access for the resource owner:

<Rule RuleId="PermitJobManagementServiceForOwner" Effect="Permit">
    <Subjects> <AnySubject/> </Subjects>
        <ResourceMatch MatchId="urn:oasis:names:tc:xacml:1.0:function:anyURI-equal">
          <AttributeValue DataType="">JobManagementService</AttributeValue>
          <ResourceAttributeDesignator AttributeId="urn:oasis:names:tc:xacml:1.0:resource:resource-id" DataType="" MustBePresent="true"/>
    <Actions> <AnyAction/> </Actions>
  <Condition FunctionId="urn:oasis:names:tc:xacml:1.0:function:x500Name-equal">
    <Apply FunctionId="urn:oasis:names:tc:xacml:1.0:function:x500Name-one-and-only">
      <SubjectAttributeDesignator AttributeId="urn:oasis:names:tc:xacml:1.0:subject:subject-id" DataType="urn:oasis:names:tc:xacml:1.0:data-type:x500Name" MustBePresent="true"/>
    <Apply FunctionId="urn:oasis:names:tc:xacml:1.0:function:x500Name-one-and-only">
      <ResourceAttributeDesignator AttributeId="owner" DataType="urn:oasis:names:tc:xacml:1.0:data-type:x500Name" MustBePresent="true"/>

12. Proxy certificate support


First, a warning: proxies are not really supported in UNICORE, except for a very limited set of usage scenarios. Many "normal" things will not work with proxy certificates. Thus, only use this feature if really strictly necessary. No feature in UNICORE requires proxies

Proxies are supported in two ways in UNICORE

  • transport-layer security and authentication via the UNICORE gateway

  • enable usage of GSI based software such as GridFTP

This document provides information and configuration snippets for the second usage scenario. Information about the first case can be found on the SourceForge Wiki page EnableProxySupport.

12.1. TLS proxy support

Using proxies for TLS means that the proxy certificate is used by the client to establish the SSL connection. You must use a gateway with the appropriate configuration for this to work. On the UNICORE/X side it is necessary to set a property in uas.config :


12.2. GSI tools support

Your UNICORE client needs to create and send the proxy. Both UCC and URC support this, please consult your client documentation for the details.

12.2.1. Storing the proxy in the job directory

First, you need to enable a handler on the web services engine. In the unicorex/conf/wsrflite.xml, add a handler definition on the target system service:

  <service name="TargetSystemService" wsrf="true" persistent="true">
   <!-- additional proxy extraction handler definition -->
   <handler type="in" class=""/>

The handler can also be added for all services like this:

  <!-- add proxy extract handler on all services.
       This needs to be done *before* the service definitions -->
  <globalHandler type="in" class=""/>

  <service name="...">


Secondly, you need to modify the XNJS configuration to enable a component that stores the proxy in the format expected by GSI (no encryption, PEM format).

So open the XNJS config file (e.g. conf/xnjs.xml) and edit the ProcessingChain section.

    <eng:ProcessingChain actionType="JSDL" jobDescriptionType="{}JobDefinition">
    <!-- stores proxy to uspace -->
    <!-- usual entries -->

12.2.2. Configuring gridftp

Using GridFTP basically works out of the box, if the client sends a proxy and you have Globus installed on your TSI login node. However it can be customised using two settings in the XNJS config file ("xnjs.xml" or "xnjs_legacy.xml").

    <!-- name / path of the executable -->
    <eng:Property name="globus-url-copy" value="/usr/local/bin/globus-url-copy"/>
    <!-- additional parameters for globus-url-copy -->
    <eng:Property name="globus-url-copy.parameters" value=""/>

13. XtreemFS support

XtreemFS is a distributed filesystem (see

XtreemFS can be mounted locally at more than one UNICORE site, making it desirable to have an optimized way of moving files used in UNICORE jobs into and out of XtreemFS.

To achieve this, UNICORE supports a special URL scheme "xtreemfs://" for data staging (i.e. moving data into the job directory prior to execution, and moveing data out of the job directory after execution).

As an example, in their jobs users can write (using a UCC example):


   { From: "xtreemfs://CN=test/test.txt", To: "infile", },


to have a file staged in from XtreemFS.

13.1. Site setup

At a site that wishes to support XtreemFS, two ways of providing access are possible. If XtreemFS is mounted locally and accessible to the UNICORE TSI, it is required to define the mount point in CONF/uas.config :


In this case, data will simply be copied by the TSI.

If XtreemFS is not mounted locally, it is possible to define the URL of a UNICORE Storage which provides access to XtreemFS


In this case, data will be moved using the usual UNICORE file transfer mechanism.