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https://issues.apache.org/jira/browse/KAFKA-4492?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15729341#comment-15729341
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ASF GitHub Bot commented on KAFKA-4492:
---------------------------------------
GitHub user dguy opened a pull request:
https://github.com/apache/kafka/pull/2226
KAFKA-4492: java.lang.IllegalStateException: Attempting to put a clean
entry for key... into NamedCache
The NamedCache wasn't correctly dealing with its re-entrant nature. This
would result in the LRU becoming corrupted, and the above exception occurring
during eviction. For example:
Cache A: dirty key 1
eviction runs on Cache A
Node for key 1 gets marked as clean
Entry for key 1 gets flushed downstream
Downstream there is a processor that also refers to the table fronted by
Cache A
Downstream processor puts key 2 into Cache A
This triggers an eviction of key 1 again ( it is still the oldest node as
hasn't been removed from the LRU)
As the Node for key 1 is clean flush doesn't run and it is immediately
removed from the cache.
So now we have dirtyKey set with key =1, but the value doesn't exist in the
cache.
Downstream processor tries to put key = 1 into the cache, it fails as key
=1 is in the dirtyKeySet.
You can merge this pull request into a Git repository by running:
$ git pull https://github.com/dguy/kafka cache-bug
Alternatively you can review and apply these changes as the patch at:
https://github.com/apache/kafka/pull/2226.patch
To close this pull request, make a commit to your master/trunk branch
with (at least) the following in the commit message:
This closes #2226
----
commit 926ef4b1900c6870819948e12950f215ab3998ac
Author: Damian Guy <damian....@gmail.com>
Date: 2016-12-07T14:48:34Z
fix cache bug
commit 6b6f3a57acacae1f0e4642ebc080ec9bc451e98c
Author: Damian Guy <damian....@gmail.com>
Date: 2016-12-07T17:12:47Z
add comment about cache eviction
----
> java.lang.IllegalStateException: Attempting to put a clean entry for key...
> into NamedCache
> -------------------------------------------------------------------------------------------
>
> Key: KAFKA-4492
> URL: https://issues.apache.org/jira/browse/KAFKA-4492
> Project: Kafka
> Issue Type: Bug
> Components: streams
> Affects Versions: 0.10.1.0
> Reporter: Damian Guy
> Assignee: Damian Guy
> Fix For: 0.10.2.0
>
>
> This follows on from https://issues.apache.org/jira/browse/KAFKA-4311
> The exception seems to be triggered by topologies with multiple joined
> tables. As a new record arrives in one table it triggers an eviction. The
> eviction causes a flush which will trigger a join processor. These in-turn
> does a cache lookup and if the value is not in the cache, then it will be
> retrieved from the store and put in the cache, triggering another eviction.
> And so on.
> Exception reported on mailing list
> https://gist.github.com/mfenniak/509fb82dfcfda79a21cfc1b07dafa89c
> Further investigation into this also reveals that this same eviction process
> can send the cache eviction into an infinite loop. It seems that the LRU is
> broken.
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