[
https://issues.apache.org/jira/browse/UIMA-6136?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16958009#comment-16958009
]
Marshall Schor commented on UIMA-6136:
--------------------------------------
the traces show something strange. From your description, I'm guessing that
the index comparators are almost all equal. Yet, it seems the get operation,
which does first a hash, and then loops throught the bucket of equal hash hits,
finds that bucket to be millions long.
So, I think there's an actual bug somewhere in this implementation, which
causes the cache.get to return null or a WeakReference which has been
"cleared", causing it to over and over add the same index comparator to the
cache.
If you have any kind of a small test case :) ...
> FSIndexComparatorImpl.equalsWithoutType() gets slow for many CASes with the
> same TS
> -----------------------------------------------------------------------------------
>
> Key: UIMA-6136
> URL: https://issues.apache.org/jira/browse/UIMA-6136
> Project: UIMA
> Issue Type: Bug
> Components: UIMA
> Affects Versions: 3.1.0SDK
> Reporter: Richard Eckart de Castilho
> Priority: Minor
> Attachments: 2019-10-21_22-23-37.png, 2019-10-21_22-44-25.png
>
>
> When creating several hundred CASes with the same type system, the
> `shareExisting` mechanism which is designed to save on memory starts eating
> into CPU time quite a lot.
> This screenshot shows that in my particular case, the method is called ~11mio
> times and takes the bulk of the processing time. The call hierarchy is a bit
> messed up though - actually this happens when the CASes are initialized.
> !2019-10-21_22-44-25.png|width=100%!
> The second screenshot shows the actual call hierarchy, but for some reason,
> the profile doesn't properly dive into the `equals` method here and doesn't
> count the time spent in `equalsWithoutType`.
> !2019-10-21_22-23-37.png|width=100%!!
> So either the method shouldn't be called that often - or - it should be way
> faster.
> In the example, I have like 1800 CAS instances and their type system has
> upwards of 200 types.
--
This message was sent by Atlassian Jira
(v8.3.4#803005)
