On 5/19/2017 8:33 AM, Ravi Kumar Taminidi wrote: > Hello, Scenario: Currently we have 2 Solr Servers running in 2 different > servers (linux), Is there any way can we make the Core to be located in NAS > or Network shared Drive so both the solrs using the same Index. > > Let me know if any performance issues, our size of Index is appx 1GB.
I think it's a very bad idea to try to share indexes between multiple Solr instances. You can override the locking and get it to work, and you may be able to find advice on the Internet about how to do it. I can tell you that it's outside the design intent for both Lucene and Solr. Lucene works aggressively to *prevent* multiple processes from sharing an index. In general, network storage is not a good idea for Solr. There's added latency for accessing any data, and frequently the filesystem won't support the kind of locking that Lucene wants to use, but the biggest potential problem is disk caching. Solr/Lucene is absolutely reliant on disk caching in the SOlr server's local memory for good performance. If the network filesystem cannot be cached by the client that has mounted the storage, which I believe is the case for most network filesystem types, then you're reliant on disk caching in the network server(s). For VERY large indexes, which is really the only viable use case I can imagine for network storage, it is highly unlikely that the network server(s) will have enough memory to effectively cache the data. Solr has explicit support for HDFS storage, but as I understand it, HDFS includes the ability for a client to allocate memory that gets used exclusively for caching on the client side, which allows HDFS to function like a local filesystem in ways that I don't think NFS can. Getting back to my advice about not sharing indexes -- even with SolrCloud on HDFS, multiple replicas generally do NOT share an index. A 1GB index is very small, so there's no good reason I can think of to involve network storage. I would strongly recommend local storage, and you should abandon any attempt to share the same index data between more than one Solr instance. Thanks, Shawn
