[
https://issues.apache.org/jira/browse/HADOOP-13028?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15257830#comment-15257830
]
Steve Loughran commented on HADOOP-13028:
-----------------------------------------
checkstyle are all about code going ++ on volatiles. The InputStream API says
"single thread only", and while we know HBase ignores that, we also know that
HBase cannot ever work on S3, and also that these are just little counters,
nothing critical...if someone does break the threading rules, well, the
counters will end up inaccurate.
> add low level counter metrics for S3A; use in read performance tests
> --------------------------------------------------------------------
>
> Key: HADOOP-13028
> URL: https://issues.apache.org/jira/browse/HADOOP-13028
> Project: Hadoop Common
> Issue Type: Sub-task
> Components: fs/s3, metrics
> Affects Versions: 2.8.0
> Reporter: Steve Loughran
> Assignee: Steve Loughran
> Attachments: HADOOP-13028-001.patch, HADOOP-13028-002.patch,
> HADOOP-13028-004.patch,
> org.apache.hadoop.fs.s3a.scale.TestS3AInputStreamPerformance-output.txt,
> org.apache.hadoop.fs.s3a.scale.TestS3AInputStreamPerformance-output.txt
>
>
> against S3 (and other object stores), opening connections can be expensive,
> closing connections may be expensive (a sign of a regression).
> S3A FS and individual input streams should have counters of the # of
> open/close/failure+reconnect operations, timers of how long things take. This
> can be used downstream to measure efficiency of the code (how often
> connections are being made), connection reliability, etc.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
