Client requirements

The following web browsers are supported for the XL Release user interface:

  • Chrome
  • Firefox
  • Internet Explorer 11 or later

Note: Internet Explorer Compatibility View is not supported.

Server requirements

To install the XL Release server, the following prerequisites must be met:

  • XL Release license: See XL Release licensing
  • Operating system: Microsoft Windows or a Unix-family operating system
  • Oracle Java Development Kit (JDK) and OpenJDK:
    • For XL Release 4.8.0 and later: Oracle JDK 1.8.0_25 or later

    Important: XL Release is not compatible with Java Development Kit 9 (JDK 9).

    • For XL Release 4.7.x and earlier: JDK 7 (Oracle or IBM)

Server hardware requirements

  • Multicore CPU
  • RAM: 4-6 GB of RAM available for the XL Release process. Note: Allocating more than 6 GB to the XL Release process does not show significant performance improvements.
  • Hard disk: XL Release must be installed on a hard drive that is persistent, but not NFS. Hard disk usage depends on configuration of the product. At least 100 GB of storage is recommended for the default installation that runs an embedded database. Use a fast hard drive.

Server software requirements

  • NTP synchronization between XL Release Server and Database Server(s)


HikariCP relies on accurate timers for both performance and reliability. It is imperative that your server is synchronized with a time-source such as an NTP server. Especially if your server is running within a virtual machine. Why? []Read more here](

Important: Do not rely on hypervisor settings to synchronize the clock of the virtual machine. Configure time-source synchronization inside the virtual machine.

External systems

Reference setup

XL Release server

  • Two Quad Intel(R) Xeon(R) CPU E5450 @ 3.00GHz
  • 16 GB of RAM
  • Two 300 GB 10K SAS 2.5” disks
Operating system CentOS Linux 7.2
Installed software A single XL Release instance running as a service, and monitoring systems
XL Release version 7.5.0
XL Release mode Standalone, non-clustered
Java version Oracle JRE 1.8.0_74

XL Release configuration:

Parameter Value Location Description -Xms2048m -Xmx6144m XL_RELEASE_SERVER_HOME/conf/xlr-wrapper-linux.conf Sets the heap size to minimum 2 GB and maximum 6 GB. The default values are minimum 1 GB and maximum 4 GB
threads.min 64 XL_RELEASE_SERVER_HOME/conf/xl-release-server.conf Sets the minimum number of HTTP threads to 64
threads.max 256 XL_RELEASE_SERVER_HOME/conf/xl-release-server.conf Sets the maximum number of HTTP threads to 256
xl.executors.scheduler.maxThreadsCount 50 XL_RELEASE_SERVER_HOME/conf/xl-release.conf Sets the maximum number of threads for asynchronous operations to 50
xl.database.max_pool_size 64 XL_RELEASE_SERVER_HOME/conf/xl-release.conf Sets the maximum number of threads for database pool to 64

SQL Database

  • Two Quad Intel(R) Xeon(R) CPU E5450 @ 3.00GHz
  • 16 GB of RAM
  • Two 300 GB 10K SAS 2.5” disks
Operating system CentOS Linux 7.2
XL Release persistence Postgres 9.5

Postgres configuration:

Parameter Value
max_connections 512
shared_buffers 4GB
effective_cache_size 12GB
synchronous_commit off
max_wal_size 1GB

For more details about the configuration, see tuning postgreSQL server.

This configuration supports up to 2000 concurrent users running a test set with 200 active releases, 200 templates and 200 completed releases and 200 folders, with a mean response time less then 100 milliseconds.

Note: Other configuration settings may be optimal for your environment (active-active, hot-standby) and load profile (number of concurrent users, release structure).