Re^4: [OT]Is there any module can rotate log file?

I want to rotate the rsynd server's log file.

When some rsync client boxes rsync its local dir to the rsynd server, rsynd server will log what files it received from the clientbox. And I want to analyze the rsyncd server's log file in an hour interval, then extract what files it received from the client boxes and do some process on these files.

So I want to rotate rsyncd server's log file by hourly, but I am afraid that I maybe rotate the server log file while the server is also updating the log file, when these two actions happen to the same log file at the same time, will be there something bad happen, like some logs will be lost?

Comment on Re^4: [OT]Is there any module can rotate log file?

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Re^5: [OT]Is there any module can rotate log file? by JavaFan (Canon) on Oct 14, 2008 at 10:58 UTC
Typically what you do when rotating log files is to rename the current log file - and leave it alone for a while. Many daemons open the log file once, and only close it when they are done. Renaming an open file is ok, the process is only using the handle, it doesn't care about the rename. It may be that the main rsynd process needs to be send a SIGHUP - but you'll have to check that. Sometimes a daemon opens a log file, and then when it has to do work, it forks, giving its child an open file handle. Typically, on a SIGHUP the main daemon closes and reopens any handles. But if the main daemon doesn't keep open handles, there's no need.	[reply]

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Re^5: [OT]Is there any module can rotate log file?
by JavaFan (Canon) on Oct 14, 2008 at 10:58 UTC

It may be that the main rsynd process needs to be send a SIGHUP - but you'll have to check that. Sometimes a daemon opens a log file, and then when it has to do work, it forks, giving its child an open file handle. Typically, on a SIGHUP the main daemon closes and reopens any handles. But if the main daemon doesn't keep open handles, there's no need.

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