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https://issues.apache.org/jira/browse/HBASE-11927?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14542302#comment-14542302
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Apekshit Sharma commented on HBASE-11927:
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Native lib is not a requirement. In many of my initial runs, there was no
native lib unless i explicitly compiled it. If native is not present (checked
[here|https://github.com/apache/hadoop/blob/cbf0ae742ae3db964550df11c4044d3e16013959/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/util/DataChecksum.java#L298]),
it falls back to java's implementation initialized
[here|http://hbase.apache.org/book.html#hadoop.native.lib].
On cleaning up ChecksumType, it did occur to me to remove it since there wasn't
anything substantial left, but finding ~50 usages, I thought it might be better
to do that separately, avoiding cluttering in this patch and all. Mapping
function would be good idea until then.
> Use Native Hadoop Library for HFile checksum (And flip default from CRC32 to
> CRC32C)
> ------------------------------------------------------------------------------------
>
> Key: HBASE-11927
> URL: https://issues.apache.org/jira/browse/HBASE-11927
> Project: HBase
> Issue Type: Bug
> Reporter: stack
> Assignee: Apekshit Sharma
> Attachments: HBASE-11927-v1.patch, HBASE-11927-v2.patch,
> HBASE-11927-v4.patch, HBASE-11927.patch, after-compact-2%.svg,
> after-randomWrite1M-0.5%.svg, before-compact-22%.svg,
> before-randomWrite1M-5%.svg, c2021.crc2.svg, c2021.write.2.svg,
> c2021.zip.svg, crc32ct.svg
>
>
> Up in hadoop they have this change. Let me publish some graphs to show that
> it makes a difference (CRC is a massive amount of our CPU usage in my
> profiling of an upload because of compacting, flushing, etc.). We should
> also make use of native CRCings -- especially the 2.6 HDFS-6865 and ilk -- in
> hbase but that is another issue for now.
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