On 11/17/2015 1:52 AM, 初十 wrote: > Hello everyone! > > I use solr 5.0 with the RAMDirectory and a collection with 3 replication > and 1 shard, > > the leader‘s load is more higer than others, is it a bug ?
Version 5.2 includes a fix that balances the load better so there is not such an imbalance between the leader and the other replicas when indexing. The leader will always have a slightly higher load even with this fix, because it coordinates updates with the other nodes. Upgrading to 5.3.1 would be sensible, but I would also stop using RAMDirectory. If you have enough memory to use RAMDirectory, then you have enough memory to achieve stellar performance with the index on disk too -- with the advantage that restarting Solr will not erase the index. RAMDirectory has problems of its own, which are also discussed in this article: http://blog.thetaphi.de/2012/07/use-lucenes-mmapdirectory-on-64bit.html If you switch to the typical default in 4.x and 5.x (NRTCachingDirectoryFactory, which uses MMapDirectoryFactory) then you can use a smaller heap. The OS will take care of keeping the index in memory, rather than Solr/Lucene. Thanks, Shawn