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https://issues.apache.org/jira/browse/HDFS-3032?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13221394#comment-13221394
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Kihwal Lee commented on HDFS-3032:
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The attached patch modifies DFSClient.renewLease() to handle RemoteException.
Unless it's SafeModeException, it aborts all writes. A test case was added to
make sure existing reads and new writes are unaffected and only the existing
writes fail. Without this change, DFSClient may not be freed even if
DistributedFileSystem disappears. This is because LeaseRenewer keeps a
reference to the DFSClient until the map is cleared of all writes.
> Lease renewer tries forever even if renewal is not possible
> -----------------------------------------------------------
>
> Key: HDFS-3032
> URL: https://issues.apache.org/jira/browse/HDFS-3032
> Project: Hadoop HDFS
> Issue Type: Bug
> Components: hdfs client
> Affects Versions: 0.23.0, 0.24.0, 0.23.1
> Reporter: Kihwal Lee
> Assignee: Kihwal Lee
> Fix For: 0.24.0, 0.23.2, 0.23.3
>
> Attachments: hdfs-3032.patch.txt
>
>
> When LeaseRenewer gets an IOException while attempting to renew for a client,
> it retries after sleeping 500ms. If the exception is caused by a condition
> that will never change, it keeps talking to the name node until the DFSClient
> object is closed or aborted. With the FileSystem cache, a DFSClient can stay
> alive for very long time. We've seen the cases in which node managers and
> long living jobs flooding name node with this type of calls.
> The current proposal is to abort the client when RemoteException is caught
> during renewal. LeaseRenewer already does abort on all clients when it sees a
> SocketTimeoutException.
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