[Cluster-devel] skipping unused services, cman_tool join -A

[Cluster-devel] skipping unused services, cman_tool join -A

[David Teigland]

To avoid loading+running services that you don't use (e.g. to avoid bugs
crashing the system from a service you're not using)

add to cluster.conf

<service name="corosync_cman" ver="0"/>
<service name="openais_ckpt" ver="0"/>

run cman_tool join -A

(or set CMAN_JOIN_OPTS env var)

Dave

[Cluster-devel] skipping unused services, cman_tool join -A

[David Teigland]

On Fri, Sep 25, 2009 at 02:27:52PM -0500, David Teigland wrote:
> To avoid loading+running services that you don't use (e.g. to avoid bugs
> crashing the system from a service you're not using)
> 
> add to cluster.conf
> 
> <service name="corosync_cman" ver="0"/>
> <service name="openais_ckpt" ver="0"/>
> 
> run cman_tool join -A

this worked when I used it for a while last spring, but it's now failing:

# cman_tool join -d -A
Starting /usr/sbin/corosync corosync -f
CMAN_DEBUG=255
COROSYNC_DEFAULT_CONFIG_IFACE=xmlconfig:cmanpreconfig
CMAN_PIPE=4
Sep 25 14:32:37 corosync [MAIN  ] Corosync Cluster Engine ('1.0.0'): started and ready to provide service.
Sep 25 14:32:37 corosync [MAIN  ] Successfully read config from /etc/cluster/cluster.conf
Sep 25 14:32:37 corosync [MAIN  ] Successfully parsed cman config
Sep 25 14:32:37 corosync [TOTEM ] Initializing transmit/receive security: libtomcrypt SOBER128/SHA1HMAC (mode 0).
Sep 25 14:32:37 corosync [TOTEM ] The network interface [10.15.84.132] is now up.
Sep 25 14:32:37 corosync [CMAN  ] CMAN 1253561438 (built Sep 21 2009 15:12:43) started
Sep 25 14:32:37 corosync [SERV  ] Service initialized 'corosync CMAN membership service 2.90'
Sep 25 14:32:37 corosync [SERV  ] Service initialized 'openais checkpoint service B.01.01'
Sep 25 14:32:37 corosync [QUORUM] Using quorum provider quorum_cman
Sep 25 14:32:37 corosync [SERV  ] Service initialized 'corosync cluster quorum service v0.1'
forked process ID is 8908
corosync running, process ID is 8908
waiting for cman to start
corosync died: Error, reason code is 9

[Cluster-devel] skipping unused services, cman_tool join -A

[David Teigland]

On Fri, Sep 25, 2009 at 02:31:05PM -0500, David Teigland wrote:
> On Fri, Sep 25, 2009 at 02:27:52PM -0500, David Teigland wrote:
> > To avoid loading+running services that you don't use (e.g. to avoid bugs
> > crashing the system from a service you're not using)
> > 
> > add to cluster.conf
> > 
> > <service name="corosync_cman" ver="0"/>
> > <service name="openais_ckpt" ver="0"/>
> > 
> > run cman_tool join -A
> 
> this worked when I used it for a while last spring, but it's now failing:

The problem was the corosync_cman service, which cman loads itself.
With just the openais_ckpt service it works fine.

Dave

[Cluster-devel] skipping unused services, cman_tool join -A

[David Teigland]

On Fri, Sep 25, 2009 at 02:27:52PM -0500, David Teigland wrote:
> To avoid loading+running services that you don't use (e.g. to avoid bugs
> crashing the system from a service you're not using)
> 
> add to cluster.conf
> 
> <service name="corosync_cman" ver="0"/>
> <service name="openais_ckpt" ver="0"/>
> 
> run cman_tool join -A
> 
> (or set CMAN_JOIN_OPTS env var)

Currently cman_tool loads the list of services defined by
"openaisserviceenablestable", which is clm, evt, ckpt, msg, lck, tmr.

I suggest that by default cman_tool only load the services that we use,
namely ckpt (and cman of course).  If someone wants to use another of the
services, they can use cluster.conf <service> to load it.

I don't think this suggestion went over very well last time I brought it
up, but recently the trend has been shifting toward narrowing our exposure
to things we've tested... so I'm tossing it out one more time.

Dave

[Cluster-devel] skipping unused services, cman_tool join -A

[Steven Dake]

On Wed, 2010-01-27 at 14:49 -0600, David Teigland wrote:
> On Fri, Sep 25, 2009 at 02:27:52PM -0500, David Teigland wrote:
> > To avoid loading+running services that you don't use (e.g. to avoid bugs
> > crashing the system from a service you're not using)
> > 
> > add to cluster.conf
> > 
> > <service name="corosync_cman" ver="0"/>
> > <service name="openais_ckpt" ver="0"/>
> > 
> > run cman_tool join -A
> > 
> > (or set CMAN_JOIN_OPTS env var)
> 
> Currently cman_tool loads the list of services defined by
> "openaisserviceenablestable", which is clm, evt, ckpt, msg, lck, tmr.
> 
> I suggest that by default cman_tool only load the services that we use,
> namely ckpt (and cman of course).  If someone wants to use another of the
> services, they can use cluster.conf <service> to load it.
> 
> I don't think this suggestion went over very well last time I brought it
> up, but recently the trend has been shifting toward narrowing our exposure
> to things we've tested... so I'm tossing it out one more time.
> 
> Dave
> 

Unfortunately this is not possible because it would break rolling
upgrades as I have stated in the past.

Regards
-steve

[Cluster-devel] skipping unused services, cman_tool join -A

[David Teigland]

On Wed, Jan 27, 2010 at 01:51:38PM -0700, Steven Dake wrote:
> On Wed, 2010-01-27 at 14:49 -0600, David Teigland wrote:
> > On Fri, Sep 25, 2009 at 02:27:52PM -0500, David Teigland wrote:
> > > To avoid loading+running services that you don't use (e.g. to avoid bugs
> > > crashing the system from a service you're not using)
> > > 
> > > add to cluster.conf
> > > 
> > > <service name="corosync_cman" ver="0"/>
> > > <service name="openais_ckpt" ver="0"/>
> > > 
> > > run cman_tool join -A
> > > 
> > > (or set CMAN_JOIN_OPTS env var)
> > 
> > Currently cman_tool loads the list of services defined by
> > "openaisserviceenablestable", which is clm, evt, ckpt, msg, lck, tmr.
> > 
> > I suggest that by default cman_tool only load the services that we use,
> > namely ckpt (and cman of course).  If someone wants to use another of the
> > services, they can use cluster.conf <service> to load it.
> > 
> > I don't think this suggestion went over very well last time I brought it
> > up, but recently the trend has been shifting toward narrowing our exposure
> > to things we've tested... so I'm tossing it out one more time.

> Unfortunately this is not possible because it would break rolling
> upgrades as I have stated in the past.

cman makes config adjustments upon seeing <cman upgrading="yes"/>, could
it not do that for services?

Dave

[Cluster-devel] skipping unused services, cman_tool join -A

[Steven Dake]

On Wed, 2010-01-27 at 15:38 -0600, David Teigland wrote:
> On Wed, Jan 27, 2010 at 01:51:38PM -0700, Steven Dake wrote:
> > On Wed, 2010-01-27 at 14:49 -0600, David Teigland wrote:
> > > On Fri, Sep 25, 2009 at 02:27:52PM -0500, David Teigland wrote:
> > > > To avoid loading+running services that you don't use (e.g. to avoid bugs
> > > > crashing the system from a service you're not using)
> > > > 
> > > > add to cluster.conf
> > > > 
> > > > <service name="corosync_cman" ver="0"/>
> > > > <service name="openais_ckpt" ver="0"/>
> > > > 
> > > > run cman_tool join -A
> > > > 
> > > > (or set CMAN_JOIN_OPTS env var)
> > > 
> > > Currently cman_tool loads the list of services defined by
> > > "openaisserviceenablestable", which is clm, evt, ckpt, msg, lck, tmr.
> > > 
> > > I suggest that by default cman_tool only load the services that we use,
> > > namely ckpt (and cman of course).  If someone wants to use another of the
> > > services, they can use cluster.conf <service> to load it.
> > > 
> > > I don't think this suggestion went over very well last time I brought it
> > > up, but recently the trend has been shifting toward narrowing our exposure
> > > to things we've tested... so I'm tossing it out one more time.
> 
> > Unfortunately this is not possible because it would break rolling
> > upgrades as I have stated in the past.
> 
> cman makes config adjustments upon seeing <cman upgrading="yes"/>, could
> it not do that for services?
> 

The cluster stack integration team can use corosync as it sees fit.

Please note the corosync dev team has no bandwidth available to deal
with rolling upgrade breakage outside of our currently tested load order
this late in the RHEL6 lifecycle.  If the cluster stack integration team
takes full responsibility for on-wire roll validation, bug fixes,
support, documentation, etc then I have no objections.

Regards
-steve

> Dave
> 

[Cluster-devel] skipping unused services, cman_tool join -A

[Christine Caulfield]

On 27/01/10 21:38, David Teigland wrote:
> On Wed, Jan 27, 2010 at 01:51:38PM -0700, Steven Dake wrote:
>> On Wed, 2010-01-27 at 14:49 -0600, David Teigland wrote:
>>> On Fri, Sep 25, 2009 at 02:27:52PM -0500, David Teigland wrote:
>>>> To avoid loading+running services that you don't use (e.g. to avoid bugs
>>>> crashing the system from a service you're not using)
>>>>
>>>> add to cluster.conf
>>>>
>>>> <service name="corosync_cman" ver="0"/>
>>>> <service name="openais_ckpt" ver="0"/>
>>>>
>>>> run cman_tool join -A
>>>>
>>>> (or set CMAN_JOIN_OPTS env var)
>>>
>>> Currently cman_tool loads the list of services defined by
>>> "openaisserviceenablestable", which is clm, evt, ckpt, msg, lck, tmr.
>>>
>>> I suggest that by default cman_tool only load the services that we use,
>>> namely ckpt (and cman of course).  If someone wants to use another of the
>>> services, they can use cluster.conf<service>  to load it.
>>>
>>> I don't think this suggestion went over very well last time I brought it
>>> up, but recently the trend has been shifting toward narrowing our exposure
>>> to things we've tested... so I'm tossing it out one more time.
>
>> Unfortunately this is not possible because it would break rolling
>> upgrades as I have stated in the past.
>
> cman makes config adjustments upon seeing<cman upgrading="yes"/>, could
> it not do that for services?


So, let me get this straight. For a cman upgrade you want to load the 
same services as before. But for a new full-featured RHEL6 cluster suite 
you think we should load fewer services, thus removing features ?

To me it seems like a pointless bit of added complication, for us and 
users. If the service is still to be shipped then what do we gain by 
simply making it more difficult to use? So far Perry's argument is that 
we don't *ship* things we can't support, thus preventing people from 
using them at all unless they compile it themselves. But this is 
different in that we have to ship the openais modules anyway, so 
disabling them is merely being wilfully obscure. It's a bit like 
shipping a command-line tool that was in RHEL5, but on RHEL6 insists on 
having the first parameter "PLEASE" before it will do anything.

I'm not really passionately in favour of either way, I just don't see 
any benefit to us, or (more importantly) to customers, from changing it.

Chrissie

[Cluster-devel] skipping unused services, cman_tool join -A

[David Teigland]

On Thu, Jan 28, 2010 at 09:11:06AM +0000, Christine Caulfield wrote:
> So, let me get this straight. For a cman upgrade you want to load the 
> same services as before. But for a new full-featured RHEL6 cluster suite 
> you think we should load fewer services, thus removing features ?

Exactly, removing unnecessary features is one of the nicest features we
can add IMO!

> To me it seems like a pointless bit of added complication, for us and 
> users. If the service is still to be shipped then what do we gain by 
> simply making it more difficult to use? So far Perry's argument is that 
> we don't *ship* things we can't support, thus preventing people from 
> using them at all unless they compile it themselves. But this is 
> different in that we have to ship the openais modules anyway, so 
> disabling them is merely being wilfully obscure. It's a bit like 
> shipping a command-line tool that was in RHEL5, but on RHEL6 insists on 
> having the first parameter "PLEASE" before it will do anything.
> 
> I'm not really passionately in favour of either way, I just don't see 
> any benefit to us, or (more importantly) to customers, from changing it.

We were trying to stick to technical issues and leave all the "support"
issues to higher-ups, but support is clearly part of it.  This came up
because we do not want to support these other services in any official
way, I've been told.  So, the step of not loading these services is a
first, small, necessary step toward not supporting them.  Next, others can
sort out whether a product should leave out the services, or include with
caveats, or something else...

I'm not passionately in favor of either way either, I was just trying to
help sort our the technical steps involved in unsupporting them.

Dave

[Cluster-devel] skipping unused services, cman_tool join -A

[Ryan O'Hara]

On Wed, Jan 27, 2010 at 02:49:25PM -0600, David Teigland wrote:
> On Fri, Sep 25, 2009 at 02:27:52PM -0500, David Teigland wrote:
> > To avoid loading+running services that you don't use (e.g. to avoid bugs
> > crashing the system from a service you're not using)
> > 
> > add to cluster.conf
> > 
> > <service name="corosync_cman" ver="0"/>
> > <service name="openais_ckpt" ver="0"/>
> > 
> > run cman_tool join -A
> > 
> > (or set CMAN_JOIN_OPTS env var)
> 
> Currently cman_tool loads the list of services defined by
> "openaisserviceenablestable", which is clm, evt, ckpt, msg, lck, tmr.
> 
> I suggest that by default cman_tool only load the services that we use,
> namely ckpt (and cman of course).  If someone wants to use another of the
> services, they can use cluster.conf <service> to load it.
> 
> I don't think this suggestion went over very well last time I brought it
> up, but recently the trend has been shifting toward narrowing our exposure
> to things we've tested... so I'm tossing it out one more time.
> 
> Dave

I completely agree. Regardless of which services are supported, tech
preview, etc., we should only load the service(s) that are actually
used by cluster suite.

Ryan