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https://issues.apache.org/jira/browse/HBASE-6833?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13458382#comment-13458382
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Elliott Clark commented on HBASE-6833:
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Windows can have a more accurate normal system clock however it causes a lot of
cpu load so is not always done: See:
http://msdn.microsoft.com/en-us/library/dd757624%28VS.85%29.aspx Calling that
works but it's frowned upon unless you really need timers that are < 10 ms
resolution.
https://blogs.oracle.com/dholmes/entry/inside_the_hotspot_vm_clocks
Seems to suggest that using the System.nanoTime will give the correct time as
determined by QueryPerformanceFrequency. So our timing can use nanoTime
converted to ms. This will only work on modernish hardware and modernish
windows. However I think that's probably good enough.
That still leaves the timers. Are there any cases where our timers must be 1ms
accurate ? If it is then the above link seems to suggest that setting a timer
that's not a multiple of 10ms will cause java to set the clock timer to 1 ms
(though on older hardware I seem to remember that the api is ignored).
> [WINDOWS] Java Milisecond precision on Windows
> ----------------------------------------------
>
> Key: HBASE-6833
> URL: https://issues.apache.org/jira/browse/HBASE-6833
> Project: HBase
> Issue Type: Sub-task
> Affects Versions: 0.96.0, 0.94.3
> Reporter: Enis Soztutar
> Assignee: Enis Soztutar
> Labels: windows
>
> HBase relies on the system clock obtained by System.currentTimeMilis() to
> supply the version, if it is not provided by the client in Put's and
> Delete's. At HBASE-6832 and HBASE-6826, we discovered that on some platforms,
> the milis clock might not be updated every milisecond, which might cause
> unexpected behavior. We also did some preliminary analysis there.
> In this issue, we can further discuss and inspect whether it is a problem for
> main target platforms and if so what can be done.
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