hadoop-hdfs-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Tsz Wo Nicholas Sze (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (HDFS-8578) On upgrade, Datanode should process all storage/data dirs in parallel
Date Thu, 10 Dec 2015 01:29:11 GMT

    [ https://issues.apache.org/jira/browse/HDFS-8578?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15049820#comment-15049820
] 

Tsz Wo Nicholas Sze commented on HDFS-8578:
-------------------------------------------

There are two different problems:
# data dirs are processed sequentially;
# OOM if all data dirs are processed in parallel.

I suggest that we fix #1 first and then fix #2 in a separated JIRA in order to keep the patch
simple.  Also, #2 need more discussion.  We should also have numParallelThreads configurable
for the moment due to #2.  At least, users could set it to numParallelThreads to 1 to avoid
#2.  What do you think?

> On upgrade, Datanode should process all storage/data dirs in parallel
> ---------------------------------------------------------------------
>
>                 Key: HDFS-8578
>                 URL: https://issues.apache.org/jira/browse/HDFS-8578
>             Project: Hadoop HDFS
>          Issue Type: Improvement
>          Components: datanode
>            Reporter: Raju Bairishetti
>            Assignee: Vinayakumar B
>            Priority: Critical
>         Attachments: HDFS-8578-01.patch, HDFS-8578-02.patch, HDFS-8578-03.patch, HDFS-8578-04.patch,
HDFS-8578-05.patch, HDFS-8578-06.patch, HDFS-8578-07.patch, HDFS-8578-08.patch, HDFS-8578-09.patch,
HDFS-8578-10.patch, HDFS-8578-11.patch, HDFS-8578-12.patch, HDFS-8578-13.patch, HDFS-8578-14.patch,
HDFS-8578-branch-2.6.0.patch, HDFS-8578-branch-2.7-001.patch, HDFS-8578-branch-2.7-002.patch
>
>
> Right now, during upgrades datanode is processing all the storage dirs sequentially.
Assume it takes ~20 mins to process a single storage dir then  datanode which has ~10 disks
will take around 3hours to come up.
> *BlockPoolSliceStorage.java*
> {code}
>    for (int idx = 0; idx < getNumStorageDirs(); idx++) {
>       doTransition(datanode, getStorageDir(idx), nsInfo, startOpt);
>       assert getCTime() == nsInfo.getCTime() 
>           : "Data-node and name-node CTimes must be the same.";
>     }
> {code}
> It would save lots of time during major upgrades if datanode process all storagedirs/disks
parallelly.
> Can we make datanode to process all storage dirs parallelly?



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)

Mime
View raw message