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HBase, mail # user - Short-circuit reads


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Short-circuit reads
David Koch 2013-01-27, 22:29
Hello,

I read about "short circuit reads" in the HBase documentation's performance
section[1] and was wondering what people's experiences were using this in a
production setting.

Also,

1. Since only one dedicated user can take advantage of the feature do you
launch all jobs as this user?
2. Can dfs.client.read.shortcircuit be set to false for jobs wich are not
launched by the short-circuit user in order to avoid exceptions? In other
words - can this setting be overriden by the client configuration's
hbase-site.xml?
3. In the same context, it is suggested to enable HBase internal
checksums[2]. Is this a feature which can be enabled in HBase 0.92.1 which
is part of the Cloudera 4.1.x release?

Thank you,

/David

[1] http://hbase.apache.org/book/perf.hdfs.html#ftn.d2145e7370
[2] https://issues.apache.org/jira/browse/HBASE-5074