I am using solr 6.1.0. We have 2 shards and each has one replica. When I checked shard1 log, I found that commit process was going to slow for some collection.
Slow commit: 2020-08-25 09:08:10.328 INFO (commitScheduler-124-thread-1) [c:forms s:shard1 r:core_node1 x:forms] o.a.s.u.DirectUpdateHandler2 start commit{,optimize=false,openSearcher=true,waitSearcher=true,expungeDeletes=false,softCommit=true,prepareCommit=false} 2020-08-25 09:08:11.424 INFO (commitScheduler-124-thread-1) [c:forms s:shard1 r:core_node1 x:forms] o.a.s.s.SolrIndexSearcher Opening [Searcher@5def3a5a[forms] main] 2020-08-25 09:08:11.932 INFO (commitScheduler-124-thread-1) [c:forms s:shard1 r:core_node1 x:forms] o.a.s.u.DirectUpdateHandler2 end_commit_flush 2020-08-25 09:08:11.935 INFO (commitScheduler-124-thread-1) [c:forms s:shard1 r:core_node1 x:forms] o.a.s.u.DirectUpdateHandler2 start commit{,optimize=false,openSearcher=true,waitSearcher=true,expungeDeletes=false,softCommit=true,prepareCommit=false} 2020-08-25 09:08:13.676 INFO (commitScheduler-124-thread-1) [c:forms s:shard1 r:core_node1 x:forms] o.a.s.s.SolrIndexSearcher Opening [Searcher@15c82f14[forms] main] 2020-08-25 09:08:14.071 INFO (commitScheduler-124-thread-1) [c:forms s:shard1 r:core_node1 x:forms] o.a.s.u.DirectUpdateHandler2 end_commit_flush I have found that all threads other than commitScheduler-124-thread-1 were fast.(commitScheduler-115-thread-1,commitScheduler-123-thread-1,commitScheduler-121-thread-1,commitScheduler-128-thread-1) what is the reason for slow commit? Why other threads are not slow? Here is my full log: shard1: https://drive.google.com/file/d/1jim55pbYxQPORpGJSNjmek5OdraGX79h/view shard1 replica: https://drive.google.com/file/d/1o34kEO1ZZwPE6eF1ppxsQnwL7wLqcx-o/view Regards, Vishal Patel <http://aka.ms/weboutlook>