is it a good idea to run multiple Solr instances on one physical machine? When i read one of the comments in this nice article, I think they run 2 Solr instances on one machine. I have 2 machines available, and want to shard the Solr indexes over maybe 5 shards. What do you think?
For full capacity we need 40 Servers with a total of 80 index shards. A single shard needs up to 20 GB disk space. Currently we are running the cluster with 30 servers and 60 index shards.
We run 4 shards with ~40GB each on a single server. An important thing you need to take care of is RAM usage, especially in the cases with large cache sizes. WE allocate about 16GB per each shard.
You didn't say anything about your qps rates (queries per second), as handling high qps might require replication. In that case you would store less shards on a single server.
Also from our experience: the less shards you have, the better is the search performance for the cross-shard distributed search, since you spend less CPU time on merging.
