[Pacemaker] Heartbeat Anything cmdline_options vs. Removing active resource from a group

[Andrew Beekhof]

On Tue, Mar 5, 2013 at 10:43 AM, Reid, Mike <MBReid at thepei.com> wrote:
> Attached is an excerpt from our two node (active/passive) Web cluster. We
> are currently launching uWSGI via the ocf:heartbeat:anything RA (see below).
>
> I would like to make some slight changes to the "cmdline_options" argument
> on our running cluster... (via "crm configure edit")
>
> Do I need to stop the resWSGI resource first before making this type of
> change?

No. The cluster will detect the change and restart the resource (and
anything that depends on it) as necessary.
In general, it is safe to make whatever changes are necessary - as
long as you are confident the changes themselves are correct :)

> Does it matter that it's in a co-located resource group? I am not
> sure if the best approach is to remove it from the group, stop/delete, and
> re-add with the adjusted cmdline_options or if heatbeat:anything RA allows
> adjusting said arguments on-the-fly?
>
> Appreciate any advice on best practices when updating against currently
> running cluster. I have read about setting maintenance-mode=true during
> planned maintenance like this (to prevent failover, etc), but I wanted to
> confirm the best approach when changing existing resources vs. adding new
> ones, especially when grouped.
>
>
> ...
>
> primitive resFS ocf:heartbeat:Filesystem \
> params device="/dev/drbd/by-res/repdata" directory="/data" fstype="ext4" \
> op monitor interval="120s"
>
> primitive resPROXY ocf:heartbeat:nginx \
> params conffile="/etc/nginx/nginx.conf" \
> op monitor interval="60s" \
> op start interval="0" timeout="40"
>
> primitive resWSGI ocf:heartbeat:anything \
>
> params binfile="/usr/local/bin/uwsgi" cmdline_options="--emperor
> /etc/uwsgi/apps-enabled/ --emperor-pidfile /var/run/uwsgi.pid
> --catch-exceptions --daemonize /var/log/uwsgi.log --enable-threads"
> pidfile="/var/run/uwsgi.pid" \
> op start interval="0" timeout="20" \
> op stop interval="0" timeout="30" \
> op monitor interval="20" \
> meta target-role="Started"
>
> group web resFS resWSGI resPROXY
>
> ...
>
> colocation web_on_drbd inf: web msDRBD:Master
>
> ...
>
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