HowTos/Working with JRE
From Scalix Wiki
Common Notes
- According to Oracle licensing of the JRE, Scalix can not distribute the JRE packages inside the Scalix installer anymore, so you will need to visit oracle site, download and install JRE
- Java 1.7: http://www.oracle.com/technetwork/java/javase/downloads/server-jre7-downloads-1931105.html
- In Scalix v.12.0 currently only JRE 1.5 and above is supported
(NOTE: if you plan to use ActiveDirectory or LDAPsync and scalix 12.0 ONLY JRE v. 1.5 is supported due a known bug with JRE 1.6 and 1.7 Advanced omldapsync How-To)
- In many systems like centos/rhel/oracle linux openjdk (opensource java implementation) is already included in distributive and can be installed using standard package installation procedure (yum, yast, etc.)
- We don't recommend using openjdk on production systems because it can cause slowdowns, higher CPU/Memory usage and can cause instability and unexpected errors. While you can install Scalix 12.0 with the openjdk we suggest that you use the OPENjdk with systems that are non-production, testing system or low load servers.
How Scalix installer determines JRE presence and version
Since v12.0, the Scalix installer tries to determine available java version in 2 steps
- it tries to execute "java -version" command. If it fails, installer assumes JRE is not available (even if you downloaded and installed jre from 3rd party location) - see next section
- it compares command output and tries to parse java version; if it fits installer requirements, java test is passed
How to install JRE
Starting from version 12.0, Scalix doesn't try to find available java, it leans on system in this case (assuming "java" command can be executed). In general, there're 2 options
- if you installed openjdk, "java" command is already available and there won't be any unexpected issues, other than the potential ones described above.
- if you downloaded and installed JRE from Oracle site, it's not enough to install it, you need to explicitly tell system what JRE to use. You can use jre configuration guide for centos for more details.
