On 21 Jun 2014, at 5:18 am, f...@vmware.com wrote: > Hi, > > New to this list and hope I can get some help here. > > I'm using pacemaker 1.0.10 and heartbeat 3.0.5 for a two-node cluster. I'm > having split-brain problem when heartbeat messages sometimes get dropped when > system is under high load. However the problem is it never recover back when > system load became low. > > I created a test setup to test this by setting dead time to 6 seconds, and > continuously dropping one-way heartbeat packets (udp dst port 694) for 5~8 > seconds and resume the traffic for 1~2 seconds using iptables. After the > system got into split-brain state, I stop the test and allow all heartbeat > traffic to go through. Sometimes the system recovered by sometimes it didn't. > There are various symptoms when the system didn't recovered from split-brain: > > 1. In one instance, cl_status listnodes becomes empty. The syslog keeps > showing > 2014-06-19T18:59:57+00:00 node-0 heartbeat: [daemon.warning] [2853]: WARN: > Message hist queue is filling up (436 messages in queue) > 2014-06-19T18:59:57+00:00 node-0 heartbeat: [daemon.debug] [2853]: debug: > hist->ackseq =12111 > 2014-06-19T18:59:57+00:00 node-0 heartbeat: [daemon.debug] [2853]: debug: > hist->lowseq =12111, hist->hiseq=12547 > 2014-06-19T18:59:57+00:00 node-0 heartbeat: [daemon.debug] [2853]: debug: > expecting from node-1 > 2014-06-19T18:59:57+00:00 node-0 heartbeat: [daemon.debug] [2853]: debug: > it's ackseq=12111 > > 2. In another instance, cl_status nodestatus <node> shows both nodes are > active, but "crm_mon -1" shows that each of the two nodes thinks itself is > the DC, and peer node is offline. Pengine process is running on one node > only. The node not running pengine (but still thinks itself is DC) has log > shows crmd terminated pengine because it detected peer is active. After that, > the peer status keeps flapping between dead and active, but pengine has never > being started again. The last log shows the peer is active (after I stopped > the test and allow all traffic). However "crm_mon -1" shows itself is the DC > and peer is offline as: > > [root@node-1 ~]# crm_mon -1 > ============ > Last updated: Fri Jun 20 19:12:23 2014 > Stack: Heartbeat > Current DC: node-1 (bf053fc5-5afd-b483-2ad2-3c9fc354f7fa) - partition with > quorum > Version: 1.0.9-da7075976b5ff0bee71074385f8fd02f296ec8a3 > 2 Nodes configured, unknown expected votes > 1 Resources configured. > ============ > > Online: [ node-1 ] > OFFLINE: [ node-0 ] > > cluster (heartbeat:ha): Started node-1 > > > Any help, like pointer to the source code where the problem might be, or any > existing bug filed for this (I did some search but didn't find matched > symptoms) is appreciated.
This is happening at the heartbeat level. Not much pacemaker can do I'm afraid. Perhaps look to see if heartbeat is "real time" scheduled, if not that may explain why its being staved of CPU and can't get its messages out. > > Thanks, > -Kaiwei > _______________________________________________ > Linux-HA mailing list > Linux-HA@lists.linux-ha.org > http://lists.linux-ha.org/mailman/listinfo/linux-ha > See also: http://linux-ha.org/ReportingProblems
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_______________________________________________ Linux-HA mailing list Linux-HA@lists.linux-ha.org http://lists.linux-ha.org/mailman/listinfo/linux-ha See also: http://linux-ha.org/ReportingProblems
