[
https://issues.apache.org/jira/browse/HDFS-14361?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16793450#comment-16793450
]
star edited comment on HDFS-14361 at 3/15/19 8:30 AM:
------------------------------------------------------
[~brahmareddy], please wait.
Maybe we should reconsider the design doc [^Multiple-Standby-NameNodes_V1.pdf]
. The following code is from that doc:
{code:java}
boolean sendRequest = needCheckpoint || isPrimaryCheckPointer
|| secsSinceLast >= checkpointConf.getQuietPeriod();{code}
Further more, SNN will send download image request as shown in comments above
line 429 in 3 cases:
* rollback request
* are the checkpointer
* are outside the quiet period
But from the patch only in later two cases will SNN send download request. I
think it causes issue HDFS-12248.
{code:java}
boolean sendRequest = isPrimaryCheckPointer
|| secsSinceLast >= checkpointConf.getQuietPeriod();{code}
I think we should move isPrimaryCheckPointer outside of 'if' block to avoid a
inconsistent state that there are more than 1 SNN with isPrimaryCheckPointer =
true, though it will not break anything.
Fix code like this:
{code:java}
boolean sendRequest = needRollbackCheckpoint || isPrimaryCheckPointer
|| secsSinceLast >= checkpointConf.getQuietPeriod();{code}
Or we should fix the comments.
was (Author: starphin):
[~brahmareddy], please wait.
Maybe we should reconsider the design doc [^Multiple-Standby-NameNodes_V1.pdf]
. The following code is from that doc:
{code:java}
boolean sendRequest = needCheckpoint || isPrimaryCheckPointer
|| secsSinceLast >= checkpointConf.getQuietPeriod();{code}
Further more, SNN will send download image request as shown in comments above
line 429 in 3 cases:
* rollback request
* are the checkpointer
* are outside the quiet period
But from the patch only in later two cases will SNN send download request. I
think it causes issue HDFS-12248.
boolean sendRequest = isPrimaryCheckPointer
|| secsSinceLastUpload >= checkpointConf.getQuietPeriod();
I think we should move isPrimaryCheckPointer outside of 'if' block to avoid a
inconsistent state that there are more than 1 SNN with isPrimaryCheckPointer =
true, though it will not break anything.
Fix code like this:
boolean sendRequest = needRollbackCheckpoint || isPrimaryCheckPointer
|| secsSinceLastUpload >= checkpointConf.getQuietPeriod();
Thus all SNN will send request everytime rollbackCheckpoint is triggered.
Or we should fix the comments.
> SNN will always upload fsimage
> ------------------------------
>
> Key: HDFS-14361
> URL: https://issues.apache.org/jira/browse/HDFS-14361
> Project: Hadoop HDFS
> Issue Type: Bug
> Components: ha, namenode
> Affects Versions: 3.2.0
> Reporter: hunshenshi
> Priority: Major
> Fix For: 3.2.0
>
>
> Related to -HDFS-12248.-
> {code:java}
> boolean sendRequest = isPrimaryCheckPointer
> || secsSinceLastUpload >= checkpointConf.getQuietPeriod();
> doCheckpoint(sendRequest);
> {code}
> If sendRequest is true, SNN will upload fsimage. But isPrimaryCheckPointer
> always is true,
> {code:java}
> if (ie == null && ioe == null) {
> //Update only when response from remote about success or
> lastUploadTime = monotonicNow();
> // we are primary if we successfully updated the ANN
> this.isPrimaryCheckPointer = success;
> }
> {code}
> isPrimaryCheckPointer should be outside the if condition.
> If the ANN update was not successful, then isPrimaryCheckPointer should be
> set to false.
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
---------------------------------------------------------------------
To unsubscribe, e-mail: hdfs-issues-unsubscr...@hadoop.apache.org
For additional commands, e-mail: hdfs-issues-h...@hadoop.apache.org
