_System Requirements - Software

Java Version
Oracle JDK (1)	1.8 (since Crowd 2.7.2). 1.7. 1.6 (deprecated), 1.5, 1.4
OpenJDK	1.7
Operating Systems
Microsoft Windows (2)
Linux / Solaris (2)
Apple Mac OS X (2)	10.7 with Oracle JDK
Application Servers
Apache Tomcat (3)	7.0.x (Crowd ships with Apache Tomcat 7.0.42) 6.0.x
Databases
MySQL (4)	5.0.37 and later
Oracle	11g (Tested on 11.2.0.2.0) 10g (Tested on 10.2.0.1)
PostgreSQL	9.2   8.x, 7.x
Microsoft SQL Server	2012, 2008 R2, 2008, 2005
HSQLDB (5)	(For evaluation only.)
Web Browsers
Chrome	Latest stable version supported
Microsoft Internet Explorer (Windows)	8, 9, 10 7 (deprecated) 6
Mozilla Firefox (all platforms)	Latest stable version supported 3.x 2.x
Safari	Latest stable version supported
Opera

Notes:
1. JDK:

• It is not enough to have the JRE only. Please ensure that you have the full JDK. You can download the Java SE Development Kit (JDK) from the Oracle website.
• Once the JDK is installed, you will need to set the JAVA_HOME environment variable, pointing to the root directory of the JDK. Some JDK installers set this automatically (check by typing 'echo %JAVA_HOME%' in a DOS prompt, or 'echo $JAVA_HOME' in a shell). If it is not set, please see Setting JAVA_HOME.

2. Operating systems: Crowd is a pure Java application and should run on any platform provided the Java runtime platform requirements are satisfied.

3. Tomcat: Deploying multiple Atlassian applications in a single Tomcat container is not supported. We do not test this configuration and upgrading any of the applications (even for point releases) is likely to break it. There are also a number of known issues with this configuration. See this FAQ for more information.

There are also a number of practical reasons why we do not support deploying multiple Atlassian applications in a single Tomcat container. Firstly, you must shut down Tomcat to upgrade any application and secondly, if one application crashes, the other applications running in that Tomcat container will be inaccessible.

Finally, we recommend not deploying any other applications to the same Tomcat container that runs Crowd, especially if these other applications have large memory requirements or require additional libraries in Tomcat's lib subdirectory.

4. MySQL: Please ensure that you set transaction isolation to 'read-committed' instead of the default 'repeatable-read', as described in the database configuration guide.

5. HSQLDB: Crowd ships with a built-in HSQL database, which is fine for evaluation purposes but is somewhat susceptible to data loss during system crashes. For production environments we recommend that you configure Crowd to use an external database.