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https://issues.apache.org/jira/browse/HDFS-14158?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16744018#comment-16744018
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Timo Walter commented on HDFS-14158:
------------------------------------
Hi [~ajisakaa],
you said: "If periodMSec becomes longer than 5 minutes, the checkpointer sleeps
longer than 5 minutes after checkpointing and we cannot check the transaction
count of the edit log when sleeping"
But if you look in the source code, where the value of *periodMsec* gets
assigned, you find only this code section (File: Checkpointer.java):
{code:java}
//Main work loop of the Checkpointer
public void run() {
// Check the size of the edit log once every 5 minutes.
long periodMSec = 5 * 60; // 5 minutes
if(checkpointConf.getPeriod() < periodMSec) {
periodMSec = checkpointConf.getPeriod();
}
{code}
First, *periodMsec* gets his default value of 5 minutes (5*60). After that
(next line) the if-statement checks, wether the configured period is lower than
the default one (5 minutes). If it's lower, *periodMsec* gets the lower value.
BUT when it's > than 5 minutes, nothing happens.
--> *periodMsec* is always 5 minuts or lower.
i reproduced this issue on my own HDFS cluster. The checkpointer node
checkpoints every 5 minutes and ignores everything > 5 minutes.
If I'm wrong with my suggestion, correct me please ;)
Thank you! ;)
> Checkpointer ignores configured time period > 5 minutes
> -------------------------------------------------------
>
> Key: HDFS-14158
> URL: https://issues.apache.org/jira/browse/HDFS-14158
> Project: Hadoop HDFS
> Issue Type: Bug
> Components: namenode
> Affects Versions: 2.8.1
> Reporter: Timo Walter
> Priority: Minor
> Labels: checkpoint, hdfs, namenode
>
> The checkpointer always triggers a checkpoint every 5 minutes and ignores the
> flag "*dfs.namenode.checkpoint.period*", if its greater than 5 minutes.
> See the code below (in Checkpointer.java):
> {code:java}
> //Main work loop of the Checkpointer
> public void run() {
> // Check the size of the edit log once every 5 minutes.
> long periodMSec = 5 * 60; // 5 minutes
> if(checkpointConf.getPeriod() < periodMSec) {
> periodMSec = checkpointConf.getPeriod();
> }
> {code}
> If the configured period ("*dfs.namenode.checkpoint.period*") is lower than 5
> minutes, you choose use the configured one. But it always ignores it, if it's
> greater than 5 minutes.
>
> In my opinion, the if-expression should be:
> {code:java}
> if(checkpointConf.getPeriod() > periodMSec) {
> periodMSec = checkpointConf.getPeriod();
> }
> {code}
>
> Then "*dfs.namenode.checkpoint.period*" won't get ignored.
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