On Friday, November 12, 2010, Lars Ellenberg wrote: > On Fri, Nov 12, 2010 at 05:04:43PM +0100, bs_li...@aakef.fastmail.fm wrote: > > # HG changeset patch > > # User Bernd Schubert <bernd.schub...@fastmail.fm> > > # Date 1289577717 -3600 > > # Node ID 750c5a016d8135a7170d4a2fbe0de0f98478c572 > > # Parent 0324966049c1e90b9d18c9c63041d2c73964d42f > > cl_log: Restore old logfile open/seek/write/close behaviour. > > > > This patch actually does not completely revert commit 2435:ada347da564d, > > but adds a layer to support both, open/write/close and and > > open-once, write, close/open-for signal handlers > > > > It also changes a marco into a static function. And also uses > > system IO (open/close/write) instead of libc IO (fopen/fclose/fwrite). > > Libc IO has a buffer, which is not suitable for log files (in case of > > a stonith, all the buffer and which might large, will be missing in > > log files. > > You are aware of this thread? > http://www.mail-archive.com/linux-ha-dev@lists.linux-ha.org/msg05590.html
No, sorry I did not notice that one. > > Basically I suggest to fflush every time the inner message logging loop > is done, and add an fsync for pri ERR and worse. > we can make that warning and worse, or even make it configurable. > > It should perform better than the always unbuffered approach, while > keeping similar guarantees about not losing (important) messages. I think it is a good idea to flush the kernel buffer, but do we really want to have a libc buffer? There is no way to flush the libc buffer from kernel space, e.g. with sysrq. The problem is that a remote system might stonith that system for whatever reason and it would be good to have the latest logs then. I noticed that even IPMI resets nowadays use acpi to trigger a reboot, I have not checked the kernel code yet, but in principal that allows the kernel to do an emergy flush of its buffers, but no way to do that for libc... > > Also, if you want to comment on the issues raised in > http://www.mail-archive.com/linux-ha-dev@lists.linux-ha.org/msg05598.html > about log rotation and files potentially being in use anyways, still? Anything not yet answered by those patches here? Hmm, well, we need to add the the kill action to the logrotate scripts, but those scripts are in the heartbeat package. Maybe not that optimal that heartbeat (without enabled logd) and ha-logd use the very same log files by default. Thanks, Bernd _______________________________________________________ Linux-HA-Dev: Linux-HA-Dev@lists.linux-ha.org http://lists.linux-ha.org/mailman/listinfo/linux-ha-dev Home Page: http://linux-ha.org/
