[TYPO3-Solr] Solr on Debian 7 Wheezy with tomcat 6/7

[Michael Schams]

Hi everyone,

We reached the limits of EXT:indexed_search several times now and I 
decided to have a closer look at Solr (long overdue).
My first impression is: WOW, that's pretty cool :-)

I installed Tomcat 6.0.41 and Solr 4.8.1 on a dedicated Debian 7.6 
Wheezy server by using the install script 
solr/Resources/Shell/install-solr.sh. That worked absolutely smoothly. 
Tomcat/Solr was running and I installed EXT:solr 3.0.0 on a TYPO3 6.2 
instance on a separate machine. Connections between these boxes worked 
as well - so all good.

Then I decided, I should use as much packages from the official Debian 
repo, so I re-installed the Debian system from scratch and started to 
fiddle with java-6-openjdk*, Oracle/Sun's j2sdk 7, Tomcat 6* and 7*, 
Solr 4.8.1 as well as 4.8.10... and always ran into some weird issues, 
predominately getting Solr running in Tomcat.

I know, this is not a TYPO3 related issue as such, but I wonder, if 
someone could recommend a setup under Debian 7 Wheezy?

My preference at this point in time would be:

- Tomcat 7 (Debian package "tomcat7")
- OpenJDK 7 or 8 (Debian packages)
- or: Oracle's j2sdk 7** or 8**
- Solr 4.8.1 (or the latest version if possible)

We will only access the Solr server with TYPO3 CMS 6.2 and EXT:solr 
3.0.0 (or newer), so no older versions need to be supported.

A typical issue I encounter with this setup is for example:

SEVERE: Exception starting filter SolrRequestFilter
java.lang.UnsupportedClassVersionError: 
org/apache/solr/servlet/SolrDispatchFilter : Unsupported major.minor 
version 51.0 (unable to load class 
org.apache.solr.servlet.SolrDispatchFilter)

I am aware of the documentation [1], which relates to Debian 6 Squeeze.
I also tried "install-solr-existing-tomcat.sh" [2] with tomcat6 and 
adjusted the script for tomcat7... to no avail.

Any recommendations, suggestions, tips? :-)


Cheers
Michael


[1] https://forge.typo3.org/projects/extension-solr/wiki/Setup_on_Debian

*) = Debian packages
**) =  generate as Debian packages from the upstream distributables of 
the JDK as provided by Oracle