Hi Ken - Thanks for you response. We do have seen messages in other cases like corosync [MAIN ] Corosync main process was not scheduled for 17314.4746 ms (threshold is 8000.0000 ms). Consider token timeout increase. corosync [TOTEM ] A processor failed, forming new configuration.
Is this the indication of a failure due to CPU load issues and will this get resolved if I upgrade to Corosync 2.x series ? In any case, for the current scenario, we did not see any scheduling related messages. Thanks for your help. Prasad On Mon, Aug 20, 2018 at 7:57 PM, Ken Gaillot <[email protected]> wrote: > On Sun, 2018-08-19 at 17:35 +0530, Prasad Nagaraj wrote: > > Hi: > > > > One of these days, I saw a spurious node loss on my 3-node corosync > > cluster with following logged in the corosync.log of one of the > > nodes. > > > > Aug 18 12:40:25 corosync [pcmk ] notice: pcmk_peer_update: > > Transitional membership event on ring 32: memb=2, new=0, lost=1 > > Aug 18 12:40:25 corosync [pcmk ] info: pcmk_peer_update: memb: > > vm02d780875f 67114156 > > Aug 18 12:40:25 corosync [pcmk ] info: pcmk_peer_update: memb: > > vmfa2757171f 151000236 > > Aug 18 12:40:25 corosync [pcmk ] info: pcmk_peer_update: lost: > > vm728316982d 201331884 > > Aug 18 12:40:25 corosync [pcmk ] notice: pcmk_peer_update: Stable > > membership event on ring 32: memb=2, new=0, lost=0 > > Aug 18 12:40:25 corosync [pcmk ] info: pcmk_peer_update: MEMB: > > vm02d780875f 67114156 > > Aug 18 12:40:25 corosync [pcmk ] info: pcmk_peer_update: MEMB: > > vmfa2757171f 151000236 > > Aug 18 12:40:25 corosync [pcmk ] info: ais_mark_unseen_peer_dead: > > Node vm728316982d was not seen in the previous transition > > Aug 18 12:40:25 corosync [pcmk ] info: update_member: Node > > 201331884/vm728316982d is now: lost > > Aug 18 12:40:25 corosync [pcmk ] info: send_member_notification: > > Sending membership update 32 to 3 children > > Aug 18 12:40:25 corosync [TOTEM ] A processor joined or left the > > membership and a new membership was formed. > > Aug 18 12:40:25 [4544] vmfa2757171f stonith-ng: info: > > plugin_handle_membership: Membership 32: quorum retained > > Aug 18 12:40:25 [4544] vmfa2757171f stonith-ng: notice: > > crm_update_peer_state_iter: plugin_handle_membership: Node > > vm728316982d[201331884] - state is now lost (was member) > > Aug 18 12:40:25 [4548] vmfa2757171f crmd: info: > > plugin_handle_membership: Membership 32: quorum retained > > Aug 18 12:40:25 [4548] vmfa2757171f crmd: notice: > > crm_update_peer_state_iter: plugin_handle_membership: Node > > vm728316982d[201331884] - state is now lost (was member) > > Aug 18 12:40:25 [4548] vmfa2757171f crmd: info: > > peer_update_callback: vm728316982d is now lost (was member) > > Aug 18 12:40:25 [4548] vmfa2757171f crmd: warning: > > match_down_event: No match for shutdown action on vm728316982d > > Aug 18 12:40:25 [4548] vmfa2757171f crmd: notice: > > peer_update_callback: Stonith/shutdown of vm728316982d not matched > > Aug 18 12:40:25 [4548] vmfa2757171f crmd: info: > > crm_update_peer_join: peer_update_callback: Node > > vm728316982d[201331884] - join-6 phase 4 -> 0 > > Aug 18 12:40:25 [4548] vmfa2757171f crmd: info: > > abort_transition_graph: Transition aborted: Node failure > > (source=peer_update_callback:240, 1) > > Aug 18 12:40:25 [4543] vmfa2757171f cib: info: > > plugin_handle_membership: Membership 32: quorum retained > > Aug 18 12:40:25 [4543] vmfa2757171f cib: notice: > > crm_update_peer_state_iter: plugin_handle_membership: Node > > vm728316982d[201331884] - state is now lost (was member) > > Aug 18 12:40:25 [4543] vmfa2757171f cib: notice: > > crm_reap_dead_member: Removing vm728316982d/201331884 from the > > membership list > > Aug 18 12:40:25 [4543] vmfa2757171f cib: notice: > > reap_crm_member: Purged 1 peers with id=201331884 and/or > > uname=vm728316982d from the membership cache > > Aug 18 12:40:25 [4544] vmfa2757171f stonith-ng: notice: > > crm_reap_dead_member: Removing vm728316982d/201331884 from the > > membership list > > Aug 18 12:40:25 [4544] vmfa2757171f stonith-ng: notice: > > reap_crm_member: Purged 1 peers with id=201331884 and/or > > uname=vm728316982d from the membership cache > > > > However, within seconds, the node was able to join back. > > > > Aug 18 12:40:34 corosync [pcmk ] notice: pcmk_peer_update: Stable > > membership event on ring 36: memb=3, new=1, lost=0 > > Aug 18 12:40:34 corosync [pcmk ] info: update_member: Node > > 201331884/vm728316982d is now: member > > Aug 18 12:40:34 corosync [pcmk ] info: pcmk_peer_update: NEW: > > vm728316982d 201331884 > > > > > > But this was enough time for the cluster to get into split brain kind > > of situation with a resource on the node vm728316982d being stopped > > because of this node loss detection. > > > > Could anyone help whether this could happen due to any transient > > network distortion or so ? > > Are there any configuration settings that can be applied in > > corosync.conf so that cluster is more resilient to such temporary > > distortions. > > Your corosync sensitivity of 10-second token timeout and 10 > retransimissions is already very lengthy -- likely the node was already > unresponsive for more than 10 seconds before the first message above, > so it was more than 18 seconds before it rejoined. > > It's rarely a good idea to change token_retransmits_before_loss_const; > changing token is generally enough to deal with transient network > unreliability. However 18 seconds is a really long time to raise the > token to, and it's uncertain from the information here whether the root > cause was networking or something on the host. > > I notice your configuration is corosync 1 with the pacemaker plugin; > that is a long-deprecated setup, and corosync 3 is about to come out, > so you may want to consider upgrading to at least corosync 2 and a > reasonably recent pacemaker. That would give you some reliability > improvements, including real-time priority scheduling of corosync, > which could have been the issue here if CPU load rather than networking > was the root cause. > > > > > Currently my corosync.conf looks like this : > > > > compatibility: whitetank > > totem { > > version: 2 > > secauth: on > > threads: 0 > > interface { > > member { > > memberaddr: 172.20.0.4 > > } > > member { > > memberaddr: 172.20.0.9 > > } > > member { > > memberaddr: 172.20.0.12 > > } > > > > bindnetaddr: 172.20.0.12 > > > > ringnumber: 0 > > mcastport: 5405 > > ttl: 1 > > } > > transport: udpu > > token: 10000 > > token_retransmits_before_loss_const: 10 > > } > > > > logging { > > fileline: off > > to_stderr: yes > > to_logfile: yes > > to_syslog: no > > logfile: /var/log/cluster/corosync.log > > timestamp: on > > logger_subsys { > > subsys: AMF > > debug: off > > } > > } > > service { > > name: pacemaker > > ver: 1 > > } > > amf { > > mode: disabled > > } > > > > Thanks in advance for the help. > > Prasad > > > > _______________________________________________ > > Users mailing list: [email protected] > > https://lists.clusterlabs.org/mailman/listinfo/users > > > > Project Home: http://www.clusterlabs.org > > Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch. > > pdf > > Bugs: http://bugs.clusterlabs.org > -- > Ken Gaillot <[email protected]> > _______________________________________________ > Users mailing list: [email protected] > https://lists.clusterlabs.org/mailman/listinfo/users > > Project Home: http://www.clusterlabs.org > Getting started: http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf > Bugs: http://bugs.clusterlabs.org >
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