[
https://issues.apache.org/jira/browse/HDFS-11384?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Konstantin Shvachko updated HDFS-11384:
---------------------------------------
Attachment: HDFS-11384.006.patch
* You are right, the rate of {{getBlocks}} RPCs is not guaranteed. Balancer can
only do its best. The actual rate can be only guaranteed on the NameNode, but
we don't want to go there.
I made it clear in the comment for {{BALANCER_NUM_RPC_PER_SEC}}.
* Added a decryption for delay.
* It is pretty hard to measure the rate of operations on NN. Here is what I did.
Created a spy FSNamesystem. The spy would call a modified {{getBlocks()}} when
the corresponding RPC is called.
The modified {{getBlocks()}} first calls the original method, then counts the
number of calls and the time of the first and the last call to {{getBlocks()}}.
Given the number of calls and the interval we can estimate the rate later on.
> Add option for balancer to disperse getBlocks calls to avoid NameNode's
> rpc.CallQueueLength spike
> -------------------------------------------------------------------------------------------------
>
> Key: HDFS-11384
> URL: https://issues.apache.org/jira/browse/HDFS-11384
> Project: Hadoop HDFS
> Issue Type: Improvement
> Components: balancer & mover
> Affects Versions: 2.7.3
> Reporter: yunjiong zhao
> Assignee: yunjiong zhao
> Attachments: balancer.day.png, balancer.week.png,
> HDFS-11384.001.patch, HDFS-11384.002.patch, HDFS-11384.003.patch,
> HDFS-11384.004.patch, HDFS-11384.005.patch, HDFS-11384.006.patch
>
>
> When running balancer on hadoop cluster which have more than 3000 Datanodes
> will cause NameNode's rpc.CallQueueLength spike. We observed this situation
> could cause Hbase cluster failure due to RegionServer's WAL timeout.
--
This message was sent by Atlassian JIRA
(v6.3.15#6346)
---------------------------------------------------------------------
To unsubscribe, e-mail: hdfs-issues-unsubscr...@hadoop.apache.org
For additional commands, e-mail: hdfs-issues-h...@hadoop.apache.org
