On 3/29/2017 3:21 AM, Prateek Jain J wrote: > We are having solr deployment in active passive mode. So, ideally only > one instance should be up and running at a time. That's true we only > see one instance serving requests but we do see some activity in CPU > for the standby solr instance. These instances are writing to shared > disk. My question is, why do we see activity is standby solr even if > it is not serving any requests. Is there any replication of in-memory > indexes between these instances? Any pointers to this are welcome.
Solr is not designed to work in this way. Sharing an index directory between two instances is not recommended and may cause serious issues. Each instance expects exclusive access to every index it is managing. You can disable the locking that normally prevents such sharing, but that locking exists for a reason and should not be disabled. Instead, you should use either SolrCloud's inherent index duplication technology, or the old master-slave replication that existed before SolrCloud. Disks are cheap. Taking risks with your data isn't. Thanks, Shawn