[SOLR-6678] Collection/core reload is causing a memory leak

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 4.10
• Assignee: Unassigned
• Reporter: Alexey Serba
• Created: 30/Oct/14 14:19
• Updated: 16/Oct/20 14:24

Description

I have a use case where I need to periodically reload a SolrCloud collection. Recently I did ~1k reload operations and noticed that the cluster was running slower and slower, so I connected to it with jconsole and noticed that heap was growing with every reload operation, forcing GC wasn't helping.

So I took a heap dump and noticed that I have too many SolrCore-s hanging around.

It's hard for me to grok the root cause of this, but maybe someone more knowledgable in Solr internals can figure it out by looking into this GC root path (see attached image)? If I interpret this correctly, it looks like one SolrCore is referencing another SolrCore through SolrSuggester. Maybe close hook for SolrSuggester component doesn't release everything that it should be releasing (like SolrSuggester.dictionary)?

Issue Links

• is related to: SOLR-9117 Leaking the first SolrCore after reload
• is related to: SOLR-14940 ReplicationHandler memory leak through SolrCore.closeHooks