On Thu, Apr 05, 2012 at 11:54:44AM -0500, Dimitri Maziuk wrote: > On 4/5/2012 10:09 AM, Dejan Muhamedagic wrote: > > On Wed, Apr 04, 2012 at 11:21:15AM -0500, Dimitri Maziuk wrote: > >> On 04/04/2012 10:59 AM, Dejan Muhamedagic wrote: > >>> Hi, > >> ... httpd monitor ... > >>> It may be wrong or not, that depends on what you need. > >> > >> (Another questionable choice as I recall was to consider 4xx an error. > >> Dep. on what you need, you may want to treat only some 5xx codes as > >> errors b/c the others mean apache is up and answering properly.) > > > > Isn't the status page always supposed to return, well, the > > status? > > No. From http://httpd.apache.org/docs/2.2/mod/mod_status.html: > "The Status module allows a server administrator to find out how well > their server is performing. A HTML page is presented that gives the > current server statistics in an easily readable form."
Oh, darn, I did mean that when I said "status." And the point was that it should _always_ yield some valid html. > What cluster should monitor for is that httpd is running and answering > requests. For that purpose a "404 Not found" is a success (while "500 > Internal server failure" probably isn't). OK, so getting /server-status doesn't mean that httpd is running and answering requests? > "How well the server is performing" implies that it's up and running, so > it's a valid test -- in the same sense that counting ice cubes in the > freezer compartment is a valid test to see if your fridge is working. Oh, well... and isn't it? > >> Which is precisely what I do: I monitor on the host with (more or less) > >> "lsof -i | grep httpd.+\*:http" > > > > How is that better than fetching the status page? > > It's not. It tells me httpd is running and is bound to ip/port. It does > not tell me if the port is reachable on a particular ip (but neither > does the resource agent) or whether it serves what it's supposed to > serve (but again neither does the agent since in my config > /server-status is *supposed* to return 404). > > The point is that if you tested your apache & iptables setup and http's > up and bound to the port, the reasons it wouldn't answer requests are > pretty much limited to DOS on the server or on the connection. And since > the resource agent isn't really monitoring those either, the only > practical difference is that my check has fewer breakable pieces. And that you have yet another piece of software to install and take care of :) But I'm sure you know the best. Cheers, Dejan > Dimitri > _______________________________________________ > Linux-HA mailing list > Linux-HA@lists.linux-ha.org > http://lists.linux-ha.org/mailman/listinfo/linux-ha > See also: http://linux-ha.org/ReportingProblems _______________________________________________ Linux-HA mailing list Linux-HA@lists.linux-ha.org http://lists.linux-ha.org/mailman/listinfo/linux-ha See also: http://linux-ha.org/ReportingProblems
