On Fri, Apr 20, 2007 at 11:47:29AM +0900, Simon Horman wrote: > On Thu, Apr 19, 2007 at 09:07:17PM +0200, Dejan Muhamedagic wrote: > > Hello, > > > > Recently I introduced a bug which today I fixed, but the whole > > thing left unpleasant taste. The bug gets excercised in case > > ha_logd has been setup to log through syslog. The problem is that > > there are multiple programs logging with different tags (such as > > heartbeat,cib,crm) whereas syslog allows us to specify a tag only > > with openlog. > > > > The current solution is to copy the tag to the string which was > > used with openlog before each syslog(3) call. Not exactly optimal. > > Another solution I could think of is to do closelog/openlog before > > every syslog call. Neither this one is a winner. > > I sense that the first idea may be problematic. I'm not > sure that there is anything stopping syslog implementations from > having a private copy of the tag, in which case subsequent modifications > to the original buffer will have little effect.
This is how it has been working. I screwed up logging because I failed to understand the subtleness of the idea. Afterwards, I checked the glibc and that one has been ok due to the implementation particulars. However, as you pointed out, on other platforms all bets are off. > For these reason I'd go for the closelog/openlog option. Perhaps > it could be smart enough to only closelog/openlog if the tag > differers from the previous occasion that syslog was called. > I imagine that the performance penalty for this would be bearable, > but its just a guess. I always had an impression that the openlog has been a comparatively light function. However, given the amount of logging currently done... > As for syslog, why on earth it doesn't give back a handle and thus > allow you to have multiple syslogs open simultaneously has baffled > me in the past. Old times/old code perhaps? > I guess another approach would be to fork of sysloging processes, > I guess then each process could open up syslog with a different tag, > and as long as you can IPC the logs to the relevant process, then > it should work. Just an idea. Not sure if its workable. Given the (syslog) circumstances this looks like the best approach. Thanks for the good analysis. > > -- > Horms > H: http://www.vergenet.net/~horms/ > W: http://www.valinux.co.jp/en/ > > _______________________________________________________ > 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/ -- Dejan _______________________________________________________ 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/
