[Cluster-devel] when do I need to start cpglockd

[Fabio M. Di Nitto <fdinitto@redhat.com>]

On 6/19/2012 9:24 AM, Dietmar Maurer wrote:
>> And then again, expressing an order is correct. If "Required-Start"
>> behavior in Debian is different than in other distro (I can speak for
>> Fedora/RHEL here), then clearly there needs to be some distro specific
>> "tuning".
> 
> You simply start a daemon which is not necessary.


>  And I guess you do that on 
> all distros if there is a Required-Start start dependency.

Fresh install on Fedora:

root at fedora16-node2 ~]# chkconfig --list |grep cpg
cpglockd        0:off   1:off   2:off   3:off   4:off   5:off   6:off

[root at fedora16-node2 ~]# chkconfig rgmanager on
[root at fedora16-node2 ~]# chkconfig --list |grep rg
rgmanager       0:off   1:off   2:on    3:on    4:on    5:on    6:off

[root at fedora16-node2 ~]# chkconfig --list |grep cpg
cpglockd        0:off   1:off   2:off   3:off   4:off   5:off   6:off

[reboot]

[root at fedora16-node2 ~]# ps ax|grep cpglockd
 3741 pts/1    S+     0:00 grep --color=auto cpglockd
[root at fedora16-node2 ~]#

[root at fedora16-node2 ~]# clustat
[SNIP]
 service:vip1                   fedora16-node2                 started

As you can see, rgmanager is on, cpglockd off.

At boot rgmanager starts fine, without cpglockd running.

I think the problem here is the interpretation of the LSB specifications
between different distributions. I am not going to argue which one is
right or wrong but the key issue is here:

"An init.d shell script may declare using the "Required-Start: " header
that it shall not be run until certain boot facilities are provided.
This information is used by the installation tool or the boot-time
boot-script execution facility to assure that init scripts are run in
the correct order."

In the fedora world that means that if cpglockd is enabled (via
chkconfig), the Required-Start: make sure that cpglockd is started
before rgmanager, always.

It is possible that other distributions might interpret that as:
"cpglockd must be started even if disabled" when rgmanager
Required-Start: cpglockd and rgmanager is enabled.

So based on the platform I use for testing/development, the daemon does
not start unless it is necessary :)

Fabio