[
https://issues.apache.org/jira/browse/HDFS-15915?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17351140#comment-17351140
]
Virajith Jalaparti edited comment on HDFS-15915 at 5/25/21, 3:40 PM:
---------------------------------------------------------------------
Thanks for making the changes [~shv].
Minor comment: The {{start = monotonicNow()}} should be done after the call to
{{beginTransaction(null)}} in lines 1637-1638 in {{logEdit}} method to keep it
consistent with others places (and previous implementation) where
{{endTransaction}} is called with the start time.
Verified that the added test fails if the other changes in the patch are
removed.
+1 on committing the patch once this minor comment is addressed.
was (Author: virajith):
Thanks for making the changes [~shv].
Minor comment: The {{long start = monotonicNow();}} should be done after the
call to {{beginTransaction(null);}} in lines 1637-1638 in {{logEdit}} method to
keep it consistent with others places (and previous implementation) where
{{endTransaction}} is called with the start time.
Verified that the added test fails if the other changes in the patch are
removed.
+1 on committing the patch once this minor comment is addressed.
> Race condition with async edits logging due to updating txId outside of the
> namesystem log
> ------------------------------------------------------------------------------------------
>
> Key: HDFS-15915
> URL: https://issues.apache.org/jira/browse/HDFS-15915
> Project: Hadoop HDFS
> Issue Type: Bug
> Components: hdfs, namenode
> Reporter: Konstantin Shvachko
> Assignee: Konstantin Shvachko
> Priority: Major
> Attachments: HDFS-15915-01.patch, HDFS-15915-02.patch,
> HDFS-15915-03.patch, HDFS-15915-04.patch, testMkdirsRace.patch
>
>
> {{FSEditLogAsync}} creates an {{FSEditLogOp}} and populates its fields inside
> {{FSNamesystem.writeLock}}. But one essential field the transaction id of the
> edits op remains unset until the time when the operation is scheduled for
> synching. At that time {{beginTransaction()}} will set the the
> {{FSEditLogOp.txid}} and increment the global transaction count. On busy
> NameNode this event can fall outside the write lock.
> This causes problems for Observer reads. It also can potentially reshuffle
> transactions and Standby will apply them in a wrong order.
--
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
