[
https://issues.apache.org/jira/browse/HDFS-2882?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13246810#comment-13246810
]
Todd Lipcon commented on HDFS-2882:
-----------------------------------
Trying to think through what the correct/expected behavior is here:
Scenario 1: user configures DN to point to a single cluster which doesn't match
its storage
Possible results:
1) DN keeps running, with no block pools
2) DN shuts down once its one-and-only service fails.
I think #2 is fairly clearly correct here.
----
Scenario 2: user configures DN to point to one NN. The user adds an additional
nameservice to the config and issues a -refreshNamenodes call. The newly added
nameservice is from the wrong cluster.
Possible results:
1) DN tries to connect and fails. It logs a message indicating this, but keeps
running with its existing service.
2) DN tries to connect and fails. It aborts the whole datanode.
I think #1 is correct here.
----
Scenario 3: user configures DN to point to two different NNs which are on
different clusters, and starts up.
Possible results:
1) DN connects to cluster 1, and joins the cluster. Service to Cluster 2 fails,
but the DN stays running. The admin may issue refreshNodes to try to connect
again.
2) DN connects to cluster 1 and joins the cluster. When service to cluster 2 is
rejected, the DN shuts down.
It's unclear what the correct results are here. My leaning is towards #2, but
not certain.
> DN continues to start up, even if block pool fails to initialize
> ----------------------------------------------------------------
>
> Key: HDFS-2882
> URL: https://issues.apache.org/jira/browse/HDFS-2882
> Project: Hadoop HDFS
> Issue Type: Bug
> Components: data-node
> Affects Versions: 0.24.0
> Reporter: Todd Lipcon
> Assignee: Todd Lipcon
>
> I started a DN on a machine that was completely out of space on one of its
> drives. I saw the following:
> 2012-02-02 09:56:50,499 FATAL
> org.apache.hadoop.hdfs.server.datanode.DataNode: Initialization failed for
> block pool Block pool BP-448349972-172.29.5.192-1323816762969 (storage id
> DS-507718931-172.29.5.194-11072-12978
> 42002148) service to styx01.sf.cloudera.com/172.29.5.192:8021
> java.io.IOException: Mkdirs failed to create
> /data/1/scratch/todd/styx-datadir/current/BP-448349972-172.29.5.192-1323816762969/tmp
> at
> org.apache.hadoop.hdfs.server.datanode.FSDataset$BlockPoolSlice.<init>(FSDataset.java:335)
> but the DN continued to run, spewing NPEs when it tried to do block reports,
> etc. This was on the HDFS-1623 branch but may affect trunk as well.
--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators:
https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa
For more information on JIRA, see: http://www.atlassian.com/software/jira
