[
https://issues.apache.org/jira/browse/HDFS-16182?focusedWorklogId=644885&page=com.atlassian.jira.plugin.system.issuetabpanels:worklog-tabpanel#worklog-644885
]
ASF GitHub Bot logged work on HDFS-16182:
-----------------------------------------
Author: ASF GitHub Bot
Created on: 01/Sep/21 09:14
Start Date: 01/Sep/21 09:14
Worklog Time Spent: 10m
Work Description: Neilxzn commented on pull request #3320:
URL: https://github.com/apache/hadoop/pull/3320#issuecomment-910066888
cc @jojochuang . Failed junit tests seem unrelated. Can you review this
patch again? Thanks.
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: common-issues-unsubscr...@hadoop.apache.org
For queries about this service, please contact Infrastructure at:
us...@infra.apache.org
Issue Time Tracking
-------------------
Worklog Id: (was: 644885)
Time Spent: 3h 20m (was: 3h 10m)
> numOfReplicas is given the wrong value in
> BlockPlacementPolicyDefault$chooseTarget can cause DataStreamer to fail with
> Heterogeneous Storage
> -----------------------------------------------------------------------------------------------------------------------------------------------
>
> Key: HDFS-16182
> URL: https://issues.apache.org/jira/browse/HDFS-16182
> Project: Hadoop HDFS
> Issue Type: Bug
> Components: namanode
> Affects Versions: 3.4.0
> Reporter: Max Xie
> Assignee: Max Xie
> Priority: Major
> Labels: pull-request-available
> Attachments: HDFS-16182.patch
>
> Time Spent: 3h 20m
> Remaining Estimate: 0h
>
> In our hdfs cluster, we use heterogeneous storage to store data in SSD for a
> better performance. Sometimes hdfs client transfer data in pipline, it will
> throw IOException and exit. Exception logs are below:
> ```
> java.io.IOException: Failed to replace a bad datanode on the existing
> pipeline due to no more good datanodes being available to try. (Nodes:
> current=[DatanodeInfoWithStorage[dn01_ip:5004,DS-ef7882e0-427d-4c1e-b9ba-a929fac44fb4,DISK],
>
> DatanodeInfoWithStorage[dn02_ip:5004,DS-3871282a-ad45-4332-866a-f000f9361ecb,DISK],
>
> DatanodeInfoWithStorage[dn03_ip:5004,DS-a388c067-76a4-4014-a16c-ccc49c8da77b,SSD],
>
> DatanodeInfoWithStorage[dn04_ip:5004,DS-b81da262-0dd9-4567-a498-c516fab84fe0,SSD],
>
> DatanodeInfoWithStorage[dn05_ip:5004,DS-34e3af2e-da80-46ac-938c-6a3218a646b9,SSD]],
>
> original=[DatanodeInfoWithStorage[dn01_ip:5004,DS-ef7882e0-427d-4c1e-b9ba-a929fac44fb4,DISK],
>
> DatanodeInfoWithStorage[dn02_ip:5004,DS-3871282a-ad45-4332-866a-f000f9361ecb,DISK]]).
> The current failed datanode replacement policy is DEFAULT, and a client may
> configure this via
> 'dfs.client.block.write.replace-datanode-on-failure.policy' in its
> configuration.
> ```
> After search it, I found when existing pipline need replace new dn to
> transfer data, the client will get one additional dn from namenode and check
> that the number of dn is the original number + 1.
> ```
> ## DataStreamer$findNewDatanode
> if (nodes.length != original.length + 1) {
> throw new IOException(
> "Failed to replace a bad datanode on the existing pipeline "
> + "due to no more good datanodes being available to try. "
> + "(Nodes: current=" + Arrays.asList(nodes)
> + ", original=" + Arrays.asList(original) + "). "
> + "The current failed datanode replacement policy is "
> + dfsClient.dtpReplaceDatanodeOnFailure
> + ", and a client may configure this via '"
> + BlockWrite.ReplaceDatanodeOnFailure.POLICY_KEY
> + "' in its configuration.");
> }
> ```
> The root cause is that Namenode$getAdditionalDatanode returns multi datanodes
> , not one in DataStreamer.addDatanode2ExistingPipeline.
>
> Maybe we can fix it in BlockPlacementPolicyDefault$chooseTarget. I think
> numOfReplicas should not be assigned by requiredStorageTypes.
>
>
>
>
>
>
--
This message was sent by Atlassian Jira
(v8.3.4#803005)
---------------------------------------------------------------------
To unsubscribe, e-mail: hdfs-issues-unsubscr...@hadoop.apache.org
For additional commands, e-mail: hdfs-issues-h...@hadoop.apache.org
