Many customers are asking for support of the built in solr replication mechanism available since solr 1.4
(this is not the rsync command line sync feature)
This ticket is aimed at tracking the list of customers asking for it.
mentions "there is currently no slave replication support"
2) if you have three solr nodes, having each of them tracking put an unnecessary load on the the SQL database. Solr replication makes more sense
3) many customers have been trying to do it.
It seems that with 4.14, we are not far from having it work.
see ticket 137453
The index replication works nicely but we are faced with an issue of index cleanup on the slave
2013-10-18 10:59:30,081 WARN [alfresco.solr.AlfrescoSolrEventListener] [pool-5-thread-1] Cache state error -> rebuilding
java.lang.IllegalStateException: New sub reader but no new docs ??
2013-10-18 10:59:59,674 WARN [solr.handler.SnapPuller] [pool-8-thread-1] The update handler is not an instance or sub-class of DirectUpdateHandler2. ReplicationHandler may not be able to cleanup unused index files.
We have tested adding, modifying and deleting and the Slave Solr is staying in sync with the Master Solr. The only thing is, the Slave Solr cannot cleanup after itself so the Slave is growing over time in disk usage.
What the plans with Alfresco to fully implement Solr replication as for the most part it works really well.