[
https://issues.apache.org/jira/browse/HADOOP-13726?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15907356#comment-15907356
]
Steve Loughran commented on HADOOP-13726:
-----------------------------------------
I Think the main concern of Chris (and myself) is not the operations which
fail, it's those the block for a long time before failing.
If it was across all filesystems, then the mechanism would be a disaster: on a
shared execution environment I could submit queries tying to talk to endpoints
which blocked during TCP setup, and that would kill everything, rather than
just my query.
If it's just per hash-key, then this can be defended against by: using a large
enough initial table to reduce collision risk (though please, not another
config option for now), and making sure that the hash key used in the table
isn't going put everything in the same hash bucket: want a broad spread of keys
> Enforce that FileSystem initializes only a single instance of the requested
> FileSystem.
> ---------------------------------------------------------------------------------------
>
> Key: HADOOP-13726
> URL: https://issues.apache.org/jira/browse/HADOOP-13726
> Project: Hadoop Common
> Issue Type: Improvement
> Components: fs
> Reporter: Chris Nauroth
>
> The {{FileSystem}} cache is intended to guarantee reuse of instances by
> multiple call sites or multiple threads. The current implementation does
> provide this guarantee, but there is a brief race condition window during
> which multiple threads could perform redundant initialization. If the file
> system implementation has expensive initialization logic, then this is
> wasteful. This issue proposes to eliminate that race condition and guarantee
> initialization of only a single instance.
--
This message was sent by Atlassian JIRA
(v6.3.15#6346)
---------------------------------------------------------------------
To unsubscribe, e-mail: common-issues-unsubscr...@hadoop.apache.org
For additional commands, e-mail: common-issues-h...@hadoop.apache.org
