[
https://issues.apache.org/jira/browse/HDFS-5591?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13947409#comment-13947409
]
Andrew Wang commented on HDFS-5591:
-----------------------------------
Hi Charlie, thanks for taking on this JIRA!
Overall looks good, a few review comments though:
- In StandbyCheckpointer, we could take advantage of this patch to slap
{{final}} on a few constants, e.g. {{now}}, {{uncheckpointed}},
{{secsSinceLast}}.
- In SecondaryNameNode, {{starttime}} we should actually leave as wall clock
time, it's not used in calculating checkpoint duration.
- We also need to update {{SecondaryNameNode#toString}}, so "Last Checkpoint
Time" is something like "Last Checkpoint: x seconds ago". This {{toString}}
shows up on the 2NN's WebUI, but I sincerely hope no one is parsing this to
determine the age of the fsimage.
> Checkpointing should use monotonic time when calculating period
> ---------------------------------------------------------------
>
> Key: HDFS-5591
> URL: https://issues.apache.org/jira/browse/HDFS-5591
> Project: Hadoop HDFS
> Issue Type: Bug
> Components: namenode
> Affects Versions: 2.2.0
> Reporter: Andrew Wang
> Assignee: Charles Lamb
> Priority: Minor
> Labels: newbie
> Attachments: HDFS-5591.001.patch, HDFS-5591.002.patch
>
>
> Both StandbyCheckpointer and SecondaryNameNode use {{Time.now}} rather than
> {{Time.monotonicNow}} to calculate how long it's been since the last
> checkpoint. This can lead to issues when the system time is changed.
--
This message was sent by Atlassian JIRA
(v6.2#6252)
