Re: Two node cluster, start CMAN fence the other node

"Jankowski, Chris" <Chris.Jankowski@xxxxxx> · Mon, 19 Apr 2010 14:26:23 +0000

Celso,

What 
would this limit buy you?

Honestly, I cannot see any rationale for this limit on a modern 
multicore, multi CPU server.  Note that there is a real *physical* limit 
that will activate as the load increases and that is one core being fully 
utilised by gfs control daemon.  Even with this core saturated by the gfs 
control daemon the cluster works just fine and processes > 5,000 
IO/s.

The limit made sense when you had 300 MHz single core, single CPU 
servers.  You could kill a server, if you were not 
careful.

Regards,

Chris 
Jankowski

  From: linux-cluster-bounces@xxxxxxxxxx 
  [mailto:linux-cluster-bounces@xxxxxxxxxx] On Behalf Of Celso K. 
  Webber
Sent: Monday, 19 April 2010 22:44
To: linux 
  clustering
Subject: Re:  Two node cluster, start CMAN 
  fence the other node

  Hello 
  Chris,

Regarding number 2 below, in fact the default limits are "100", 
  so Alex's configuration of "500" should increase the performance.

Of 
  couse there can be configured for unlimited, but this is something one should 
  decide by him(her)self according to the environment.

Please see this 
  link:
http://www.linuxdynasty.org/howto-increase-gfs2-performance-in-a-cluster.html

Regards,

Celso.

  From: "Jankowski, Chris" 
  <Chris.Jankowski@xxxxxx>
To: linux clustering 
  <linux-cluster@xxxxxxxxxx>
Sent: Fri, April 16, 2010 9:39:54 
  PM
Subject: Re: 
   Two node cluster, start CMAN fence the other 
  node

  Alex,

  1.
  Thank you very much.
  The 
  Cisco setup is very useful and the commands for testing multicast as 
  well.

  2
  Loking at your cluster.conf, I would have thought that any limits on 
  dlm and gfs lock rates are counterproductive in the days of multicore CPUs and 
  GbE.  They should be unlimited in my opinion.  Under high load the 
  limiting factor will be saturation of one core by gfs control daemon. 

  Regards,

  Chris Jankowski

    From: linux-cluster-bounces@xxxxxxxxxx 
    [mailto:linux-cluster-bounces@xxxxxxxxxx] On Behalf Of Alex 
    Re
Sent: Saturday, 17 April 2010 01:36
To: linux 
    clustering
Subject: Re:  Two node cluster, start 
    CMAN fence the other node

Hi Chris,

for the switches ports stuff check out this 
    url:
http://www.openais.org/doku.php?id=faq:cisco_switches

We 
    have finally configured an internal (private) VLAN joining there one NIC of 
    each blade server. Now all cluster related traffic goes through those 
    interfaces (eth2 at both servers in our case), including the traffic 
    generated by the lock_dlm of the GFS2 filesystem, just created. 

To 
    check multicast connectivity, these are two very useful commands, "nc -u 
    -vvn -z <multicast_IP> 5405" to generate some multicast udp traffic 
    and "tcpdump -i eth2 ether multicast" to check it from the other node. (eth2 
    in my particular case, of course).

I have been playing a little with 
    the lock_dlm, but here is how my cluster.conf looks now:

<?xml 
    version="1.0"?>
<cluster config_version="7" 
    name="VCluster">
    <fence_daemon 
    post_fail_delay="0" post_join_delay="25"/>

    <clusternodes>

    <clusternode name="nodeaint" nodeid="1" 
    votes="1">

    <multicast addr="239.0.0.1" interface="eth2"/>

            <fence>

                <method 
    name="1">

            <device 
    name="nodeaiLO"/>

            </method>

            </fence>

        </clusternode>

        <clusternode name="nodebint" nodeid="2" 
    votes="1">

    <multicast addr="239.0.0.1" interface="eth2"/>

            <fence>

                <method 
    name="1">

            <device 
    name="nodebiLO"/>

            </method>

            </fence>

        </clusternode>

    </clusternodes>
    <cman expected_votes="1" 
    two_node="1">
        <multicast 
    addr="239.0.0.1"/>

    </cman>

    <fencedevices>

    <fencedevice agent="fence_ilo" hostname="nodeacn" login="user" 
    name="nodeaiLO" passwd="hp"/>

    <fencedevice agent="fence_ilo" hostname="nodebcn" login="user" 
    name="nodebiLO" passwd="hp"/>

    </fencedevices>
    <rm>

        <failoverdomains/>

        <resources/>

    </rm>
    <dlm plock_ownership="1" 
    plock_rate_limit="500"/>
    <gfs_controld 
    plock_rate_limit="500"/>
</cluster>

Next 
    thing to add... I'm going to play a little with the quorum 
    devices.

Hope it helps!

Alex

On 04/16/2010 05:00 PM, 
    Jankowski, Chris wrote: 
    eparate the cluster 
    interconne

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