[Pacemaker] Frustrating fun with Pacemaker / CentOS / Apache

[Tom Weber]

Am Donnerstag, den 18.02.2010, 15:25 -0700 schrieb Tim Serong:
> On 2/19/2010 at 08:40 AM, Paul Graydon <paul at ehawaii.gov> wrote: 
> > >> I started looking into this today to find out whether it was 
> > >> possible to use another URL for testing.  According to the heartbeat 
> > >> script you can specify the parameter statusurl and as long as it has 
> > >> a body and html tag on the page you test it should work. 
> > >>       
> > > You can also set your own "testregex" which should match the 
> > > output of "statusurl". Since resource agents release 1.0.2, 
> > > apache can also do more thorough tests (see "crm ra info apache" 
> > > or ocf_heartbeat_apache(7)). 
> > > 
> > >     
> > >> So I thought I'd give it a try, but it failed.  Initially I assumed 
> > >> it was because I hadn't selected a page with the body and html tag 
> > >> (having not noticed that was a necessity) but even when against a 
> > >> page that has them it still failed.  Trying to execute the command 
> > >> it runs came up with a failure for me too, but it appears to be how 
> > >> all the arguments are presented to wget courtesy of "sh -c". 
> > >> 
> > >> It's looking for a positive return from: 
> > >> 
> > >> sh -c wget -O- -q -L http://whatever.url.youprovided | tr '\012' ' ' 
> > >> | grep -Ei "</ *body *>[[:space:]]*</ *html *>" 
> > >> 
> > >> Problem is if you cut it down to just that first section: 
> > >> sh -c wget -O- -q -L http://whatever.url.youprovided 
> > >> 
> > >> it pops back and tells you 
> > >> wget: missing URL 
> > >> Usage: wget [OPTION]... [URL]... 
> > >> 
> > >> Try `wget --help' for more options. 
> > >> 
> > >> If you execute wget without using "sh -c" in front of it it sees the 
> > >> URL and parses it successfully. 
> > >> 
> > >> Surrounding the wget string with ' marks, as in: 
> > >> sh -c 'wget -O- -q -L http://whatever.url.youprovided ' 
> > >> 
> > >> I'm trying to figure out what other options are available.  Adding 
> > >> in ' marks on line 406 of the ocf heartbeat apache script breaks it! 
> > >>       
> > > I really don't think there is a need to change anything there. 
> > > Otherwise, apache would never be able to work. If you think you 
> > > found a problem, you can try to wrap the critical part in 
> > > "set -x/+x" and we'll see what the output looks like. 
> > > 
> > > Thanks, 
> > > 
> > > Dejan 
> > >     
> > I've looked into this with fresh eyes this morning and managed to track  
> > down the problem to this addition to the related to meta  
> > target-role="Started" 
> >  
> > Not sure quite where I picked that up from, presumably one of the  
> > configurations I used as a template?  Without setting it as an attribute  
> > it works fine, tested and retested with and without that addition. 
> >  
> > This works: 
> > primitive failover-apache ocf:heartbeat:apache \ 
> >          params configfile="/etc/httpd/conf/httpd.conf"  
> > httpd="/usr/sbin/httpd" port="80" \ 
> >          op monitor interval="5s" timeout="20s"  
> > statusurl="https://valid.test.url/index.html" 
> >  
> > This doesn't: 
> > primitive failover-apache ocf:heartbeat:apache \ 
> >          params configfile="/etc/httpd/conf/httpd.conf"  
> > httpd="/usr/sbin/httpd" port="80" \ 
> >          op monitor interval="5s" timeout="20s"  
> > statusurl="https://valid.test.url/index.html" \ 
> >      meta target-role="Started" 

do you still have the group resource from your initial post in your
config? 

group web-cluster failover-ip failover-apache \
         meta target-role="Started"

> That's weird.  That attribute shouldn't make any difference in this case -
> it's just telling the cluster that it should try to start the resource,
> which is the default anyway.
> 
> > My understanding of the meta bits is a little weak, and I can't find an  
> > explanation as to what target-role is actually trying to do. 
> 
> It specifies the state the resource is meant to be in[1], i.e. stopped,
> started, or a master or slave (the latter of which you would use for an active/passive DRBD clone pair, for example).

I found that meta target-role in primitives that are members of a group
conflict with the target-role of the group, so i got rid of these in the
primitives.

  Tom