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https://issues.apache.org/jira/browse/HBASE-18847?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Rich Howarth updated HBASE-18847:
---------------------------------
Description:
The below code block starts at line 277 of HFileWriterV2.java. Class-level
synchronization in a heavily used code path has a demonstrably significant
negative effect on performance. I tested forcing a major compaction with 18
compaction threads per node; removing the synchronization resulted in an order
of magnitude performance increase, with the bottleneck then being at the disks
(where I want it to be).
synchronized (HFileWriterV2.class) {
if (WARN_CELL_WITH_TAGS && getFileContext().isIncludesTags()) {
LOG.warn("A minimum HFile version of " +
HFile.MIN_FORMAT_VERSION_WITH_TAGS
+ " is required to support cell attributes/tags. Consider setting "
+ HFile.FORMAT_VERSION_KEY + " accordingly.");
WARN_CELL_WITH_TAGS = false;
}
}
was:The below code block starts at line 277 of HFileWriterV2.java.
Class-level synchronization in a heavily used code path has a demonstrably
significant negative effect on performance. I tested forcing a major compaction
with 18 compaction threads per node; removing the synchronization resulted in
an order of magnitude performance increase, with the bottleneck then being at
the disks (where I want it to be).
> Huge performance bottleneck in HFileWriterV2 in 1.2.6
> -----------------------------------------------------
>
> Key: HBASE-18847
> URL: https://issues.apache.org/jira/browse/HBASE-18847
> Project: HBase
> Issue Type: Bug
> Affects Versions: 1.2.6
> Reporter: Rich Howarth
>
> The below code block starts at line 277 of HFileWriterV2.java. Class-level
> synchronization in a heavily used code path has a demonstrably significant
> negative effect on performance. I tested forcing a major compaction with 18
> compaction threads per node; removing the synchronization resulted in an
> order of magnitude performance increase, with the bottleneck then being at
> the disks (where I want it to be).
> synchronized (HFileWriterV2.class) {
> if (WARN_CELL_WITH_TAGS && getFileContext().isIncludesTags()) {
> LOG.warn("A minimum HFile version of " +
> HFile.MIN_FORMAT_VERSION_WITH_TAGS
> + " is required to support cell attributes/tags. Consider setting "
> + HFile.FORMAT_VERSION_KEY + " accordingly.");
> WARN_CELL_WITH_TAGS = false;
> }
> }
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