[
https://issues.apache.org/jira/browse/CASSANDRA-5581?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13661565#comment-13661565
]
Mikhail Mazursky commented on CASSANDRA-5581:
---------------------------------------------
Some notes:
* ReadCallback.get() computes timeout before calling await() which computes it
too. This looks like a bug. I fixed it, but if I'm wrong I can revert this
change;
* BulkLoader.ProgressIndicator.printProgress() was not printing correct delta
progress in the first iteration because delta time calculation was incorrect.
Fixed that by initializing lastTime to the nanoTime() of the operation start;
* SimpleCondition.await() instead of converting "time" into MILLISECONDS from
"unit" TimeUnit was convering "time" from MILLISECONDS to "unit"
TimeUnit:{noformat}
long end = System.currentTimeMillis() + unit.convert(time,
TimeUnit.MILLISECONDS);
{noformat}
Should be
{noformat}
long end = System.currentTimeMillis() + unit.toMillis(time);
{noformat}
> Use System.nanoTime() to measure intervals
> ------------------------------------------
>
> Key: CASSANDRA-5581
> URL: https://issues.apache.org/jira/browse/CASSANDRA-5581
> Project: Cassandra
> Issue Type: Improvement
> Reporter: Mikhail Mazursky
> Priority: Critical
> Attachments: trunk-5581.txt
>
>
> System.nanoTime() should always be prefered to System.currentTimeMillis() to
> measure time intervals. It's not affected by system clock adjustments & drift.
> While testing C* we found that it's very unstable if system clock drifts.
> Problems happen even under low load with tiny dataset. In our case other VMs
> on the same hardware box produced high CPU load and system clock drifted a
> lot in C* VMs. We fixed that but there is definitelly room for improvement in
> C* itself.
--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira
