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https://issues.apache.org/jira/browse/HBASE-22532?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16854604#comment-16854604
]
Zheng Hu commented on HBASE-22532:
----------------------------------
Add a log like the following:
{code}
commit f9b563e29d02204a5653eff6235a82511e9a6c08 (HEAD -> HBASE-21879)
Author: huzheng <[email protected]>
Date: Mon Jun 3 21:07:26 2019 +0800
Add debug
diff --git
a/hbase-server/src/main/java/org/apache/hadoop/hbase/io/hfile/ChecksumUtil.java
b/hbase-server/src/main/java/org/apache/hadoop/hbase/io/hfile/ChecksumUtil.java
index dc007f726a..2c94acf383 100644
---
a/hbase-server/src/main/java/org/apache/hadoop/hbase/io/hfile/ChecksumUtil.java
+++
b/hbase-server/src/main/java/org/apache/hadoop/hbase/io/hfile/ChecksumUtil.java
@@ -106,6 +106,10 @@ public class ChecksumUtil {
} catch (ChecksumException e) {
return false;
}
+ } else {
+ LOG.info(
+ "--> data.class: {}, checksums.class: {}, data.capacity: {},
checksums.capacity: " + "{}",
+ data.getClass(), checksums.getClass(), data.capacity(), checksums.capacity());
}
// If the block is a MultiByteBuff. we use a small byte[] to update the
checksum many times for
{code}
Seems many blocks with buffer.size = 130KB, because many logs say:
{code}
2019-06-03,21:39:47,691 INFO org.apache.hadoop.hbase.io.hfile.ChecksumUtil: -->
data.class: class org.apache.hadoop.hbase.nio.MultiByteBuff, checksums.class:
class org.apache.hadoop.hbase.nio.MultiByteBuff, data.capacity: 133120,
checksums.capacity: 133120
2019-06-03,21:39:47,691 INFO org.apache.hadoop.hbase.io.hfile.ChecksumUtil: -->
data.class: class org.apache.hadoop.hbase.nio.MultiByteBuff, checksums.class:
class org.apache.hadoop.hbase.nio.MultiByteBuff, data.capacity: 133120,
checksums.capacity: 133120
2019-06-03,21:39:47,691 INFO org.apache.hadoop.hbase.io.hfile.ChecksumUtil: -->
data.class: class org.apache.hadoop.hbase.nio.MultiByteBuff, checksums.class:
class org.apache.hadoop.hbase.nio.MultiByteBuff, data.capacity: 133120,
checksums.capacity: 133120
{code}
> There's still too much cpu wasting on validating checksum even if
> buffer.size=65KB
> ----------------------------------------------------------------------------------
>
> Key: HBASE-22532
> URL: https://issues.apache.org/jira/browse/HBASE-22532
> Project: HBase
> Issue Type: Sub-task
> Reporter: Zheng Hu
> Assignee: Zheng Hu
> Priority: Major
> Attachments: async-prof-pid-27827-cpu-3.svg
>
>
> After disabled the block cache, and with the following config:
> {code}
> # Disable the block cache
> hfile.block.cache.size=0
> hbase.ipc.server.allocator.buffer.size=66560
> hbase.ipc.server.reservoir.minimal.allocating.size=0
> {code}
> The ByteBuff for block should be expected to be a SingleByteBuff, which will
> use the hadoop native lib to validate the checksum, while in the cpu flame
> graph
> [async-prof-pid-27827-cpu-3.svg|https://issues.apache.org/jira/secure/attachment/12970683/async-prof-pid-27827-cpu-3.svg],
> we can still see that about 32% CPU wasted on PureJavaCrc32#update, which
> means it's not using the faster hadoop native lib.
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