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https://issues.apache.org/jira/browse/SOLR-14428?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17091714#comment-17091714
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Mike Drob commented on SOLR-14428:
----------------------------------

bq. Maybe there is an elegant way to store a stripped down FuzzyQuery in the 
cache?

I think this runs into problems with auto warming based on the contents of the 
cache when we open a new searcher. Possibly need a way to rebuild it 
afterwards, which feels like we're going backwards from LUCENE-9068.

Related, [~romseygeek] - should 
[BASE_RAM_BYTES|https://github.com/apache/lucene-solr/blob/master/lucene/core/src/java/org/apache/lucene/search/FuzzyQuery.java#L58]
 use {{FuzzyQuery.class}} instead of {{AutomatonQuery.class}}?

> FuzzyQuery has severe memory usage in 8.5
> -----------------------------------------
>
>                 Key: SOLR-14428
>                 URL: https://issues.apache.org/jira/browse/SOLR-14428
>             Project: Solr
>          Issue Type: Bug
>      Security Level: Public(Default Security Level. Issues are Public) 
>    Affects Versions: 8.5, 8.5.1
>            Reporter: Colvin Cowie
>            Assignee: Andrzej Bialecki
>            Priority: Major
>         Attachments: FuzzyHammer.java, image-2020-04-23-09-18-06-070.png, 
> screenshot-2.png, screenshot-3.png, screenshot-4.png
>
>
> I sent this to the mailing list
> I'm moving from 8.3.1 to 8.5.1, and started getting Out Of Memory Errors 
> while running our normal tests. After profiling it was clear that the 
> majority of the heap was allocated through FuzzyQuery.
> LUCENE-9068 moved construction of the automata from the FuzzyTermsEnum to the 
> FuzzyQuery's constructor.
> I created a little test ( [^FuzzyHammer.java] ) that fires off fuzzy queries 
> from random UUID strings for 5 minutes
> {code}
> FIELD_NAME + ":" + UUID.randomUUID().toString().replace("-", "") + "~2"
> {code}
> When running against a vanilla Solr 8.31 and 8.4.1 there is no problem, while 
> the memory usage has increased drastically on 8.5.0 and 8.5.1.
> Comparison of heap usage while running the attached test against Solr 8.3.1 
> and 8.5.1 with a single (empty) shard and 4GB heap:
> !image-2020-04-23-09-18-06-070.png! 
> And with 4 shards on 8.4.1 and 8.5.0:
>  !screenshot-2.png! 
> I'm guessing that the memory might be being leaked if the FuzzyQuery objects 
> are referenced from the cache, while the FuzzyTermsEnum would not have been.
> Query Result Cache on 8.5.1:
>  !screenshot-3.png! 
> ~316mb in the cache
> QRC on 8.3.1
>  !screenshot-4.png! 
> <1mb
> With an empty cache, running this query 
> _field_s:e41848af85d24ac197c71db6888e17bc~2_ results in the following memory 
> allocation
> {noformat}
> 8.3.1: CACHE.searcher.queryResultCache.ramBytesUsed:      1520
> 8.5.1: CACHE.searcher.queryResultCache.ramBytesUsed:    648855
> {noformat}
> ~1 gives 98253 and ~0 gives 6339 on 8.5.1. 8.3.1 is constant at 1520



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