[
https://issues.apache.org/jira/browse/HDFS-10301?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15246571#comment-15246571
]
Konstantin Shvachko commented on HDFS-10301:
--------------------------------------------
Hey Daryn, not sure how HDFS-9198 eliminates it from occurring. DataNodes are
still waiting for NN to process each BR, so they can timeout and send the same
block report multiple times. On the NN side, BR ops processing is
multi-threaded, so it can still interleave processing storages from different
reports. Could you please clarify, what am I missing?
> Blocks removed by thousands due to falsely detected zombie storages
> -------------------------------------------------------------------
>
> Key: HDFS-10301
> URL: https://issues.apache.org/jira/browse/HDFS-10301
> Project: Hadoop HDFS
> Issue Type: Bug
> Components: namenode
> Affects Versions: 2.6.1
> Reporter: Konstantin Shvachko
> Priority: Critical
> Attachments: zombieStorageLogs.rtf
>
>
> When NameNode is busy a DataNode can timeout sending a block report. Then it
> sends the block report again. Then NameNode while process these two reports
> at the same time can interleave processing storages from different reports.
> This screws up the blockReportId field, which makes NameNode think that some
> storages are zombie. Replicas from zombie storages are immediately removed,
> causing missing blocks.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
