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https://issues.apache.org/jira/browse/HDFS-8892?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14708067#comment-14708067
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Colin Patrick McCabe commented on HDFS-8892:
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I think this patch might be acceptable if you introduced a separate thread to
iterate over all slots, and had that thread run only every 10 minutes (or
something like that).
In general, though, I'm curious why you are interested in this? If a replica
is used, we'll check if it's valid at that point. If it's not used, it should
eventually get timed out.
> ShortCircuitCache.CacheCleaner can add Slot.isInvalid() check too
> -----------------------------------------------------------------
>
> Key: HDFS-8892
> URL: https://issues.apache.org/jira/browse/HDFS-8892
> Project: Hadoop HDFS
> Issue Type: Improvement
> Components: hdfs-client
> Affects Versions: 2.7.1
> Reporter: Ravikumar
> Assignee: kanaka kumar avvaru
> Priority: Minor
>
> Currently CacheCleaner thread checks only for cache-expiry times. It would be
> nice if it handles an invalid-slot too in an extra-pass of evictable map…
> for(ShortCircuitReplica replica:evictable.values()) {
> if(!scr.getSlot().isValid()) {
> purge(replica);
> }
> }
> //Existing code...
> int numDemoted = demoteOldEvictableMmaped(curMs);
> int numPurged = 0;
> Long evictionTimeNs = Long.valueOf(0);
> ….
> …..
> Apps like HBase can tweak the expiry/staleness/cache-size params in
> DFS-Client, so that ShortCircuitReplica will never be closed except when Slot
> is declared invalid.
> I assume slot-invalidation will happen during block-invalidation/deletes
> {Primarily triggered by compaction/shard-takeover etc..}
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