[
https://issues.apache.org/jira/browse/HDFS-9608?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15109068#comment-15109068
]
Vinayakumar B commented on HDFS-9608:
-------------------------------------
bq. Inconsistent synchronization of
org.apache.hadoop.hdfs.server.datanode.fsdataset.AvailableSpaceVolumeChoosingPolicy.balancedPreferencePercent;
locked 57% of time Unsynchronized access at
AvailableSpaceVolumeChoosingPolicy.java:57% of time Unsynchronized access at
AvailableSpaceVolumeChoosingPolicy.java:[line 159]
didnt see that coming.
IMO, its safe to remove synchronization on getConf() and setConf() in
AvailableSpaceVolumeChoosingPolicy. as its nowhere else called
> Disk IO imbalance in HDFS with heterogeneous storages
> -----------------------------------------------------
>
> Key: HDFS-9608
> URL: https://issues.apache.org/jira/browse/HDFS-9608
> Project: Hadoop HDFS
> Issue Type: Bug
> Affects Versions: 2.6.0
> Reporter: Wei Zhou
> Assignee: Wei Zhou
> Attachments: HDFS-9608.01.patch, HDFS-9608.02.patch,
> HDFS-9608.03.patch, HDFS-9608.04.patch, HDFS-9608.05.patch, HDFS-9608.06.patch
>
>
> Currently RoundRobinVolumeChoosingPolicy use a shared index to choose volumes
> in HDFS with heterogeneous storages, this leads to non-RR choosing mode for
> certain type of storage.
> Besides, it uses a shared lock for synchronization which limits the
> concurrency of volume choosing process. Volume choosing threads that
> operating on different storage types should be able to run concurrently.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
