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<p class="MsoNormal"><span style="color:#212121">>>> However, now it seems to wait that amount of time before it elects a<br>
>>> DC, even when quorum is acquired earlier. In my log snippet below,<br>
>>> with dc-deadtime 300s,<br>
>><br>
>> The dc-deadtime is not waiting for quorum, but for another DC to show<br>
>> up. If all nodes show up, it can proceed, but otherwise it has to wait.<br>
<br>
> I believe all the nodes showed up by 14:17:04, but it still waited until 14:19:26 to elect a DC:<br>
<br>
> Jan 29 14:14:25 gopher12 pacemaker-controld [123697] (peer_update_callback) info: Cluster node gopher12 is now membe (was in unknown state)<br>
> Jan 29 14:17:04 gopher12 pacemaker-controld [123697] (peer_update_callback) info: Cluster node gopher11 is now membe (was in unknown state)<br>
> Jan 29 14:17:04 gopher12 pacemaker-controld [123697] (quorum_notification_cb) notice: Quorum acquired | membership=54 members=2<br>
> Jan 29 14:19:26 gopher12 pacemaker-controld [123697] (do_log) info: Input I_ELECTION_DC received in state S_ELECTION from election_win_cb<br>
<br>
> This is a cluster with 2 nodes, gopher11 and gopher12.<br>
<br>
This is our experience with dc-deadtime too: even if both nodes in the cluster show up, dc-deadtime must elapse before the cluster starts. This was discussed on this list a while back (<a href="https://www.mail-archive.com/users@clusterlabs.org/msg03897.html">https://www.mail-archive.com/users@clusterlabs.org/msg03897.html</a></span>)<span style="color:#212121">
and an RFE came out of it (<a href="https://bugs.clusterlabs.org/show_bug.cgi?id=5310">https://bugs.clusterlabs.org/show_bug.cgi?id=5310</a></span>).
</p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I’ve worked around this by having an ExecStartPre directive for Corosync that does essentially:</p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">while ! systemctl -H ${peer} is-active corosync; do sleep 5; done</p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">With this in place, the nodes wait for each other before starting Corosync and Pacemaker. We can then use the default 20s dc-deadtime so that the DC election happens quickly once both nodes are up.</p>
<p class="MsoNormal">Thanks,</p>
<p class="MsoNormal">Chris</p>
<p class="MsoNormal"><o:p> </o:p></p>
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<b><span style="font-size:12.0pt;color:black">From: </span></b><span style="font-size:12.0pt;color:black">Users <users-bounces@clusterlabs.org> on behalf of Faaland, Olaf P. via Users <users@clusterlabs.org><br>
<b>Date: </b>Monday, January 29, 2024 at 7:46 PM<br>
<b>To: </b>Ken Gaillot <kgaillot@redhat.com>, Cluster Labs - All topics related to open-source clustering welcomed <users@clusterlabs.org><br>
<b>Cc: </b>Faaland, Olaf P. <faaland1@llnl.gov><br>
<b>Subject: </b>Re: [ClusterLabs] controlling cluster behavior on startup<o:p></o:p></span></p>
</div>
<div>
<p class="MsoNormal" style="margin-left:.5in">>> However, now it seems to wait that amount of time before it elects a<br>
>> DC, even when quorum is acquired earlier. In my log snippet below,<br>
>> with dc-deadtime 300s,<br>
><br>
> The dc-deadtime is not waiting for quorum, but for another DC to show<br>
> up. If all nodes show up, it can proceed, but otherwise it has to wait.<br>
<br>
I believe all the nodes showed up by 14:17:04, but it still waited until 14:19:26 to elect a DC:<br>
<br>
Jan 29 14:14:25 gopher12 pacemaker-controld [123697] (peer_update_callback) info: Cluster node gopher12 is now membe (was in unknown state)<br>
Jan 29 14:17:04 gopher12 pacemaker-controld [123697] (peer_update_callback) info: Cluster node gopher11 is now membe (was in unknown state)<br>
Jan 29 14:17:04 gopher12 pacemaker-controld [123697] (quorum_notification_cb) notice: Quorum acquired | membership=54 members=2<br>
Jan 29 14:19:26 gopher12 pacemaker-controld [123697] (do_log) info: Input I_ELECTION_DC received in state S_ELECTION from election_win_cb<br>
<br>
This is a cluster with 2 nodes, gopher11 and gopher12.<br>
<br>
Am I misreading that?<br>
<br>
thanks,<br>
Olaf<br>
<br>
________________________________________<br>
From: Ken Gaillot <kgaillot@redhat.com><br>
Sent: Monday, January 29, 2024 3:49 PM<br>
To: Faaland, Olaf P.; Cluster Labs - All topics related to open-source clustering welcomed<br>
Subject: Re: [ClusterLabs] controlling cluster behavior on startup<br>
<br>
On Mon, 2024-01-29 at 22:48 +0000, Faaland, Olaf P. wrote:<br>
> Thank you, Ken.<br>
><br>
> I changed my configuration management system to put an initial<br>
> cib.xml into /var/lib/pacemaker/cib/, which sets all the property<br>
> values I was setting via pcs commands, including dc-deadtime. I<br>
> removed those "pcs property set" commands from the ones that are run<br>
> at startup time.<br>
><br>
> That worked in the sense that after Pacemaker start, the node waits<br>
> my newly specified dc-deadtime of 300s before giving up on the<br>
> partner node and fencing it, if the partner never appears as a<br>
> member.<br>
><br>
> However, now it seems to wait that amount of time before it elects a<br>
> DC, even when quorum is acquired earlier. In my log snippet below,<br>
> with dc-deadtime 300s,<br>
<br>
The dc-deadtime is not waiting for quorum, but for another DC to show<br>
up. If all nodes show up, it can proceed, but otherwise it has to wait.<br>
<br>
><br>
> 14:14:24 Pacemaker starts on gopher12<br>
> 14:17:04 quorum is acquired<br>
> 14:19:26 Election Trigger just popped (start time + dc-deadtime<br>
> seconds)<br>
> 14:19:26 gopher12 wins the election<br>
><br>
> Is there other configuration that needs to be present in the cib at<br>
> startup time?<br>
><br>
> thanks,<br>
> Olaf<br>
><br>
> === log extract using new system of installing partial cib.xml before<br>
> startup<br>
> Jan 29 14:14:24 gopher12 pacemakerd [123690]<br>
> (main) notice: Starting Pacemaker 2.1.7-1.t4 | build=2.1.7<br>
> features:agent-manpages ascii-docs compat-2.0 corosync-ge-2 default-<br>
> concurrent-fencing generated-manpages monotonic nagios ncurses remote<br>
> systemd<br>
> Jan 29 14:14:25 gopher12 pacemaker-attrd [123695]<br>
> (attrd_start_election_if_needed) info: Starting an election to<br>
> determine the writer<br>
> Jan 29 14:14:25 gopher12 pacemaker-attrd [123695]<br>
> (election_check) info: election-attrd won by local node<br>
> Jan 29 14:14:25 gopher12 pacemaker-controld [123697]<br>
> (peer_update_callback) info: Cluster node gopher12 is now member<br>
> (was in unknown state)<br>
> Jan 29 14:17:04 gopher12 pacemaker-controld [123697]<br>
> (quorum_notification_cb) notice: Quorum acquired | membership=54<br>
> members=2<br>
> Jan 29 14:19:26 gopher12 pacemaker-controld [123697]<br>
> (crm_timer_popped) info: Election Trigger just popped |<br>
> input=I_DC_TIMEOUT time=300000ms<br>
> Jan 29 14:19:26 gopher12 pacemaker-controld [123697]<br>
> (do_log) warning: Input I_DC_TIMEOUT received in state S_PENDING<br>
> from crm_timer_popped<br>
> Jan 29 14:19:26 gopher12 pacemaker-controld [123697]<br>
> (do_state_transition) info: State transition S_PENDING -><br>
> S_ELECTION | input=I_DC_TIMEOUT cause=C_TIMER_POPPED<br>
> origin=crm_timer_popped<br>
> Jan 29 14:19:26 gopher12 pacemaker-controld [123697]<br>
> (election_check) info: election-DC won by local node<br>
> Jan 29 14:19:26 gopher12 pacemaker-controld [123697] (do_log) info:<br>
> Input I_ELECTION_DC received in state S_ELECTION from election_win_cb<br>
> Jan 29 14:19:26 gopher12 pacemaker-controld [123697]<br>
> (do_state_transition) notice: State transition S_ELECTION -><br>
> S_INTEGRATION | input=I_ELECTION_DC cause=C_FSA_INTERNAL<br>
> origin=election_win_cb<br>
> Jan 29 14:19:26 gopher12 pacemaker-schedulerd[123696]<br>
> (recurring_op_for_active) info: Start 10s-interval monitor<br>
> for gopher11_zpool on gopher11<br>
> Jan 29 14:19:26 gopher12 pacemaker-schedulerd[123696]<br>
> (recurring_op_for_active) info: Start 10s-interval monitor<br>
> for gopher12_zpool on gopher12<br>
><br>
><br>
> === initial cib.xml contents<br>
> <cib crm_feature_set="3.19.0" validate-with="pacemaker-3.9" epoch="9"<br>
> num_updates="0" admin_epoch="0" cib-last-written="Mon Jan 29 11:07:06<br>
> 2024" update-origin="gopher12" update-client="root" update-<br>
> user="root" have-quorum="0" dc-uuid="2"><br>
> <configuration><br>
> <crm_config><br>
> <cluster_property_set id="cib-bootstrap-options"><br>
> <nvpair id="cib-bootstrap-options-stonith-action"<br>
> name="stonith-action" value="off"/><br>
> <nvpair id="cib-bootstrap-options-have-watchdog" name="have-<br>
> watchdog" value="false"/><br>
> <nvpair id="cib-bootstrap-options-dc-version" name="dc-<br>
> version" value="2.1.7-1.t4-2.1.7"/><br>
> <nvpair id="cib-bootstrap-options-cluster-infrastructure"<br>
> name="cluster-infrastructure" value="corosync"/><br>
> <nvpair id="cib-bootstrap-options-cluster-name"<br>
> name="cluster-name" value="gopher11"/><br>
> <nvpair id="cib-bootstrap-options-cluster-recheck-inte"<br>
> name="cluster-recheck-interval" value="60"/><br>
> <nvpair id="cib-bootstrap-options-start-failure-is-fat"<br>
> name="start-failure-is-fatal" value="false"/><br>
> <nvpair id="cib-bootstrap-options-dc-deadtime" name="dc-<br>
> deadtime" value="300"/><br>
> </cluster_property_set><br>
> </crm_config><br>
> <nodes><br>
> <node id="1" uname="gopher11"/><br>
> <node id="2" uname="gopher12"/><br>
> </nodes><br>
> <resources/><br>
> <constraints/><br>
> </configuration><br>
> </cib><br>
><br>
> ________________________________________<br>
> From: Ken Gaillot <kgaillot@redhat.com><br>
> Sent: Monday, January 29, 2024 10:51 AM<br>
> To: Cluster Labs - All topics related to open-source clustering<br>
> welcomed<br>
> Cc: Faaland, Olaf P.<br>
> Subject: Re: [ClusterLabs] controlling cluster behavior on startup<br>
><br>
> On Mon, 2024-01-29 at 18:05 +0000, Faaland, Olaf P. via Users wrote:<br>
> > Hi,<br>
> ><br>
> > I have configured clusters of node pairs, so each cluster has 2<br>
> > nodes. The cluster members are statically defined in corosync.conf<br>
> > before corosync or pacemaker is started, and quorum {two_node: 1}<br>
> > is<br>
> > set.<br>
> ><br>
> > When both nodes are powered off and I power them on, they do not<br>
> > start pacemaker at exactly the same time. The time difference may<br>
> > be<br>
> > a few minutes depending on other factors outside the nodes.<br>
> ><br>
> > My goals are (I call the first node to start pacemaker "node1"):<br>
> > 1) I want to control how long pacemaker on node1 waits before<br>
> > fencing<br>
> > node2 if node2 does not start pacemaker.<br>
> > 2) If node1 is part-way through that waiting period, and node2<br>
> > starts<br>
> > pacemaker so they detect each other, I would like them to proceed<br>
> > immediately to probing resource state and starting resources which<br>
> > are down, not wait until the end of that "grace period".<br>
> ><br>
> > It looks from the documentation like dc-deadtime is how #1 is<br>
> > controlled, and #2 is expected normal behavior. However, I'm<br>
> > seeing<br>
> > fence actions before dc-deadtime has passed.<br>
> ><br>
> > Am I misunderstanding Pacemaker's expected behavior and/or how dc-<br>
> > deadtime should be used?<br>
><br>
> You have everything right. The problem is that you're starting with<br>
> an<br>
> empty configuration every time, so the default dc-deadtime is being<br>
> used for the first election (before you can set the desired value).<br>
><br>
> I can't think of anything you can do to get around that, since the<br>
> controller starts the timer as soon as it starts up. Would it be<br>
> possible to bake an initial configuration into the PXE image?<br>
><br>
> When the timer value changes, we could stop the existing timer and<br>
> restart it. There's a risk that some external automation could make<br>
> repeated changes to the timeout, thus never letting it expire, but<br>
> that<br>
> seems preferable to your problem. I've created an issue for that:<br>
><br>
><br>
> <a href="https://urldefense.us/v3/__https:/projects.clusterlabs.org/T764">https://urldefense.us/v3/__https:/projects.clusterlabs.org/T764</a>
<br>
><br>
> BTW there's also election-timeout. I'm not sure offhand how that<br>
> interacts; it might be necessary to raise that one as well.<br>
><br>
> > One possibly unusual aspect of this cluster is that these two nodes<br>
> > are stateless - they PXE boot from an image on another server - and<br>
> > I<br>
> > build the cluster configuration at boot time with a series of pcs<br>
> > commands, because the nodes have no local storage for this<br>
> > purpose. The commands are:<br>
> ><br>
> > ['pcs', 'cluster', 'start']<br>
> > ['pcs', 'property', 'set', 'stonith-action=off']<br>
> > ['pcs', 'property', 'set', 'cluster-recheck-interval=60']<br>
> > ['pcs', 'property', 'set', 'start-failure-is-fatal=false']<br>
> > ['pcs', 'property', 'set', 'dc-deadtime=300']<br>
> > ['pcs', 'stonith', 'create', 'fence_gopher11', 'fence_powerman',<br>
> > 'ip=192.168.64.65', 'pcmk_host_check=static-list',<br>
> > 'pcmk_host_list=gopher11,gopher12']<br>
> > ['pcs', 'stonith', 'create', 'fence_gopher12', 'fence_powerman',<br>
> > 'ip=192.168.64.65', 'pcmk_host_check=static-list',<br>
> > 'pcmk_host_list=gopher11,gopher12']<br>
> > ['pcs', 'resource', 'create', 'gopher11_zpool', 'ocf:llnl:zpool',<br>
> > 'import_options="-f -N -d /dev/disk/by-vdev"', 'pool=gopher11',<br>
> > 'op',<br>
> > 'start', 'timeout=805']<br>
> > ...<br>
> > ['pcs', 'property', 'set', 'no-quorum-policy=ignore']<br>
><br>
> BTW you don't need to change no-quorum-policy when you're using<br>
> two_node with Corosync.<br>
><br>
> > I could, instead, generate a CIB so that when Pacemaker is started,<br>
> > it has a full config. Is that better?<br>
> ><br>
> > thanks,<br>
> > Olaf<br>
> ><br>
> > === corosync.conf:<br>
> > totem {<br>
> > version: 2<br>
> > cluster_name: gopher11<br>
> > secauth: off<br>
> > transport: udpu<br>
> > }<br>
> > nodelist {<br>
> > node {<br>
> > ring0_addr: gopher11<br>
> > name: gopher11<br>
> > nodeid: 1<br>
> > }<br>
> > node {<br>
> > ring0_addr: gopher12<br>
> > name: gopher12<br>
> > nodeid: 2<br>
> > }<br>
> > }<br>
> > quorum {<br>
> > provider: corosync_votequorum<br>
> > two_node: 1<br>
> > }<br>
> ><br>
> > === Log excerpt<br>
> ><br>
> > Here's an except from Pacemaker logs that reflect what I'm<br>
> > seeing. These are from gopher12, the node that came up first. The<br>
> > other node, which is not yet up, is gopher11.<br>
> ><br>
> > Jan 25 17:55:38 gopher12 pacemakerd [116033]<br>
> > (main) notice: Starting Pacemaker 2.1.7-1.t4 | build=2.1.7<br>
> > features:agent-manpages ascii-docs compat-2.0 corosync-ge-2<br>
> > default-<br>
> > concurrent-fencing generated-manpages monotonic nagios ncurses<br>
> > remote<br>
> > systemd<br>
> > Jan 25 17:55:39 gopher12 pacemaker-controld [116040]<br>
> > (peer_update_callback) info: Cluster node gopher12 is now member<br>
> > (was in unknown state)<br>
> > Jan 25 17:55:43 gopher12 pacemaker-based [116035]<br>
> > (cib_perform_op) info: ++<br>
> > /cib/configuration/crm_config/cluster_property_set[@id='cib-<br>
> > bootstrap-options']: <nvpair id="cib-bootstrap-options-dc-<br>
> > deadtime"<br>
> > name="dc-deadtime" value="300"/><br>
> > Jan 25 17:56:00 gopher12 pacemaker-controld [116040]<br>
> > (crm_timer_popped) info: Election Trigger just popped |<br>
> > input=I_DC_TIMEOUT time=300000ms<br>
> > Jan 25 17:56:01 gopher12 pacemaker-based [116035]<br>
> > (cib_perform_op) info: ++<br>
> > /cib/configuration/crm_config/cluster_property_set[@id='cib-<br>
> > bootstrap-options']: <nvpair id="cib-bootstrap-options-no-quorum-<br>
> > policy" name="no-quorum-policy" value="ignore"/><br>
> > Jan 25 17:56:01 gopher12 pacemaker-controld [116040]<br>
> > (abort_transition_graph) info: Transition 0 aborted by cib-<br>
> > bootstrap-options-no-quorum-policy doing create no-quorum-<br>
> > policy=ignore: Configuration change | cib=0.26.0<br>
> > source=te_update_diff_v2:464<br>
> > path=/cib/configuration/crm_config/cluster_property_set[@id='cib-<br>
> > bootstrap-options'] complete=true<br>
> > Jan 25 17:56:01 gopher12 pacemaker-controld [116040]<br>
> > (controld_execute_fence_action) notice: Requesting fencing (off)<br>
> > targeting node gopher11 | action=11 timeout=60<br>
> ><br>
> ><br>
> > _______________________________________________<br>
> > Manage your subscription:<br>
> > <a href="https://urldefense.us/v3/__https:/lists.clusterlabs.org/mailman/listinfo/users">https://urldefense.us/v3/__https:/lists.clusterlabs.org/mailman/listinfo/users</a>
<br>
> ><br>
> > ClusterLabs home:<br>
> > <a href="https://urldefense.us/v3/__https:/www.clusterlabs.org/">https://urldefense.us/v3/__https:/www.clusterlabs.org/</a>
<br>
> ><br>
> --<br>
> Ken Gaillot <kgaillot@redhat.com><br>
><br>
--<br>
Ken Gaillot <kgaillot@redhat.com><br>
<br>
_______________________________________________<br>
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