[ClusterLabs] Antw: Re: Notification agent and Notification recipients
Sriram
sriram.ec at gmail.com
Mon Aug 14 06:32:17 EDT 2017
Hi Ken,
I used the alerts as well, seems to be not working.
Please check the below configuration
[root at node1 alerts]# pcs config show
Cluster Name:
Corosync Nodes:
Pacemaker Nodes:
node1 node2 node3
Resources:
Resource: TRR (class=ocf provider=heartbeat type=TimingRedundancyRA)
Operations: start interval=0s timeout=60s (TRR-start-interval-0s)
stop interval=0s timeout=20s (TRR-stop-interval-0s)
monitor interval=10 timeout=20 (TRR-monitor-interval-10)
Stonith Devices:
Fencing Levels:
Location Constraints:
Resource: TRR
Enabled on: node1 (score:100) (id:location-TRR-node1-100)
Enabled on: node2 (score:200) (id:location-TRR-node2-200)
Enabled on: node3 (score:300) (id:location-TRR-node3-300)
Ordering Constraints:
Colocation Constraints:
Ticket Constraints:
Alerts:
Alert: alert_file (path=/usr/share/pacemaker/alert_file.sh)
Options: debug_exec_order=false
Meta options: timeout=15s
Recipients:
Recipient: recipient_alert_file_id
(value=/usr/share/pacemaker/alert_file.log)
Resources Defaults:
resource-stickiness: INFINITY
Operations Defaults:
No defaults set
Cluster Properties:
cluster-infrastructure: corosync
dc-version: 1.1.15-11.el7_3.4-e174ec8
default-action-timeout: 240
have-watchdog: false
no-quorum-policy: ignore
placement-strategy: balanced
stonith-enabled: false
symmetric-cluster: false
Quorum:
Options:
/usr/share/pacemaker/alert_file.sh does not get called whenever I trigger a
scenario for failover.
Please let me know if I m missing anything.
Regards,
Sriram.
On Tue, Aug 8, 2017 at 8:29 PM, Ken Gaillot <kgaillot at redhat.com> wrote:
> On Tue, 2017-08-08 at 17:40 +0530, Sriram wrote:
> > Hi Ulrich,
> >
> >
> > Please see inline.
> >
> > On Tue, Aug 8, 2017 at 2:01 PM, Ulrich Windl
> > <Ulrich.Windl at rz.uni-regensburg.de> wrote:
> > >>> Sriram <sriram.ec at gmail.com> schrieb am 08.08.2017 um
> > 09:30 in Nachricht
> > <CAMvdjurcQc6t=ZfGr=cRL25Xq0Je9h9F_TvZXyxVAn3n
> > +Dvcgw at mail.gmail.com>:
> > > Hi Ken & Jan,
> > >
> > > In the cluster we have, there is only one resource running.
> > Its a OPT-IN
> > > cluster with resource-stickiness set to INFINITY.
> > >
> > > Just to clarify my question, lets take a scenario where
> > there are four
> > > nodes N1, N2, N3, N4
> > > a. N1 comes up first, starts the cluster.
> >
> > The cluster will start once it has a quorum.
> >
> > > b. N1 Checks that there is no resource running, so it will
> > add the
> > > resource(R) with the some location constraint(lets say score
> > 100)
> > > c. So Resource(R) runs in N1 now.
> > > d. N2 comes up next, checks that resource(R) is already
> > running in N1, so
> > > it will update the location constraint(lets say score 200)
> > > e. N3 comes up next, checks that resource(R) is already
> > running in N1, so
> > > it will update the location constraint(lets say score 300)
> >
> > See my remark on quorum above.
> >
> > Yes you are right, I forgot to mention it.
> >
> >
> > > f. N4 comes up next, checks that resource(R) is already
> > running in N1, so
> > > it will update the location constraint(lets say score 400)
> > > g. For the some reason, if N1 goes down, resource(R) shifts
> > to N4(as its
> > > score is higher than anyone).
> > >
> > > In this case is it possible to notify the nodes N2, N3 that
> > newly elected
> > > active node is N4 ?
> >
> > What type of notification, and what would the node do with it?
> > Any node in the cluster always has up to date configuration
> > information. So it knows the status of the other nodes also.
> >
> >
> > I agree that the node always has upto date configuration information,
> > but an application or a thread needs to poll for that information. Is
> > there any way, where the notifications are received through some
> > action function in RA. ?
>
> Ah, I misunderstood your situation, I thought you had a cloned resource.
>
> For that, the alerts feature (available in Pacemaker 1.1.15 and later)
> might be useful:
>
> http://clusterlabs.org/doc/en-US/Pacemaker/1.1-pcs/html-
> single/Pacemaker_Explained/index.html#idm139900098676896
>
>
> >
> >
> > Regards,
> > Sriram.
> >
> > >
> > > I went through clone notifications and master-slave, Iooks
> > like it either
> > > requires identical resources(Anonymous) or Unique or
> > Stateful resources to
> > > be running
> > > in all the nodes of the cluster, where as in our case there
> > is only
> > > resource running in the whole cluster.
> >
> > Maybe the main reason for not having notifications is that if
> > a node fails hard, it won't be able to send out much status
> > information to the other nodes.
> >
> > Regards,
> > Ulrich
> >
> > >
> > > Regards,
> > > Sriram.
> > >
> > >
> > >
> > >
> > > On Mon, Aug 7, 2017 at 11:28 AM, Sriram
> > <sriram.ec at gmail.com> wrote:
> > >
> > >>
> > >> Thanks Ken, Jan. Will look into the clone notifications.
> > >>
> > >> Regards,
> > >> Sriram.
> > >>
> > >> On Sat, Aug 5, 2017 at 1:25 AM, Ken Gaillot
> > <kgaillot at redhat.com> wrote:
> > >>
> > >>> On Thu, 2017-08-03 at 12:31 +0530, Sriram wrote:
> > >>> >
> > >>> > Hi Team,
> > >>> >
> > >>> >
> > >>> > We have a four node cluster (1 active : 3 standby) in
> > our lab for a
> > >>> > particular service. If the active node goes down, one of
> > the three
> > >>> > standby node becomes active. Now there will be (1
> > active : 2
> > >>> > standby : 1 offline).
> > >>> >
> > >>> >
> > >>> > Is there any way where this newly elected node sends
> > notification to
> > >>> > the remaining 2 standby nodes about its new status ?
> > >>>
> > >>> Hi Sriram,
> > >>>
> > >>> This depends on how your service is configured in the
> > cluster.
> > >>>
> > >>> If you have a clone or master/slave resource, then clone
> > notifications
> > >>> is probably what you want (not alerts, which is the path
> > you were going
> > >>> down -- alerts are designed to e.g. email a system
> > administrator after
> > >>> an important event).
> > >>>
> > >>> For details about clone notifications, see:
> > >>>
> > >>>
> > http://clusterlabs.org/doc/en-US/Pacemaker/1.1-pcs/html-sing
> > >>>
> > le/Pacemaker_Explained/index.html#_clone_resource_agent_
> requirements
> > >>>
> > >>> The RA must support the "notify" action, which will be
> > called when a
> > >>> clone instance is started or stopped. See the similar
> > section later for
> > >>> master/slave resources for additional information. See the
> > mysql or
> > >>> pgsql resource agents for examples of notify
> > implementations.
> > >>>
> > >>> > I was exploring "notification agent" and "notification
> > recipient"
> > >>> > features, but that doesn't seem to
> > work. /etc/sysconfig/notify.sh
> > >>> > doesn't get invoked even in the newly elected active
> > node.
> > >>>
> > >>> Yep, that's something different altogether -- it's only
> > enabled on RHEL
> > >>> systems, and solely for backward compatibility with an
> > early
> > >>> implementation of the alerts interface. The new alerts
> > interface is more
> > >>> flexible, but it's not designed to send information
> > between cluster
> > >>> nodes -- it's designed to send information to something
> > external to the
> > >>> cluster, such as a human, or an SNMP server, or a
> > monitoring system.
> > >>>
> > >>>
> > >>> > Cluster Properties:
> > >>> > cluster-infrastructure: corosync
> > >>> > dc-version: 1.1.17-e2e6cdce80
> > >>> > default-action-timeout: 240
> > >>> > have-watchdog: false
> > >>> > no-quorum-policy: ignore
> > >>> > notification-agent: /etc/sysconfig/notify.sh
> > >>> > notification-recipient: /var/log/notify.log
> > >>> > placement-strategy: balanced
> > >>> > stonith-enabled: false
> > >>> > symmetric-cluster: false
> > >>> >
> > >>> >
> > >>> >
> > >>> >
> > >>> > I m using the following versions of pacemaker and
> > corosync.
> > >>> >
> > >>> >
> > >>> > /usr/sbin # ./pacemakerd --version
> > >>> > Pacemaker 1.1.17
> > >>> > Written by Andrew Beekhof
> > >>> > /usr/sbin # ./corosync -v
> > >>> > Corosync Cluster Engine, version '2.3.5'
> > >>> > Copyright (c) 2006-2009 Red Hat, Inc.
> > >>> >
> > >>> >
> > >>> > Can you please suggest if I m doing anything wrong or if
> > there any
> > >>> > other mechanisms to achieve this ?
> > >>> >
> > >>> >
> > >>> > Regards,
> > >>> > Sriram.
>
> --
> Ken Gaillot <kgaillot at redhat.com>
>
>
>
>
>
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