logging: file: disable buffering on the output log files #9
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While at it, I've also added commit which fixes the CI. Quite strange, that I can't see the CI running on this PR, but it runs just fine in my fork. |
Is this only when using VMware? Also what is the effect on performance when disabling buffering? |
I don't use Lua much on Windows, so I would need to test it.
Do you've any specific benchmark in the mind I could run? |
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Had a look at this again, it seems to be a Windows specific problem. If you look at the Lua implementation, it uses the standard C constants ( Now if you look that up in the Windows docs, you'll see this comment:
So It's just WIndows not supporting line-buffered mode. As for this PR, how about at the top of the module testing for Windows, and set a buffering constant to either "line" (non-Windows), or "no" (Windows). And then use that constant value. Probably add some comments to explain the difference between the platforms. |
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@ynezz I pushed a commit on your branch, implementing what I wrote above. Please have a look. Any ideas as to why CI doesn't seem to run? |
Use version 8.0.0 or greater as GitHub has deprecated older versions of the actions core libraries. References: https://github.blog/changelog/2020-10-01-github-actions-deprecating-set-env-and-add-path-commands/ Signed-off-by: Petr Štetiar <ynezz@true.cz>
This causes file-log to not show the latest lines when tailing log files on Windows. Only when the next line comes in the previous one is actually written. Signed-off-by: Petr Štetiar <ynezz@true.cz>
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k, fixed the CI, the trigger for pull-requests wasn't in the flow. |
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thx @ynezz !! |
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@Tieske just found time to test it on the same VM, seems to be fine, thanks a lot! |
I've observed following on Windows Server 2012 R2 running under VMWare
where the disk I/O is handled by
VMWare Virtual disk SCSI Disk Devicestorage.
Current line buffering makes live observing of log files with
tail -fquite unusable as the current line is always missing from the log file
until there is next line logged.
Sometimes log content is missing completly, usually when the running
application is terminated and the buffered log content is not flushed
properly to the disk.
Disabling buffering fixes the issues.
Signed-off-by: Petr Štetiar ynezz@true.cz