>>> Ken Gaillot <[email protected]> schrieb am 24.04.2017 um 22:08 in >>> Nachricht <[email protected]>: > Hi all, > > Pacemaker 1.1.17 will have a feature that people have occasionally asked > for in the past: the ability to start a node in standby mode. > > It will be controlled by an environment variable (set in > /etc/sysconfig/pacemaker, /etc/default/pacemaker, or wherever your > distro puts them): > > > # By default, nodes will join the cluster in an online state when they first > # start, unless they were previously put into standby mode. If this > variable is > # set to "standby" or "online", it will force this node to join in the > # specified state when starting. > # (experimental; currently ignored for Pacemaker Remote nodes) > # PCMK_node_start_state=default > > > As described, it will be considered experimental in this release, mainly > because it doesn't work with Pacemaker Remote nodes yet. However, I > don't expect any problems using it with cluster nodes. > > Example use cases: > > You want want fenced nodes to automatically start the cluster after a > reboot, so they contribute to quorum, but not run any resources, so the > problem can be investigated. You would leave > PCMK_node_start_state=standby permanently.
I wonder: There is a fencing mode "off" and "reboot". Why not have "reboot_standby" (and "off_standby")? The last one would put the node in standby after it has been restarted manually. Probably not very helpful, but for completeness. The other option I could think of is a "timed standby": The node would not run resources for a specified time. For those who prefer retries that fail over a dead inactive cluster. > > You want to ensure a newly added node joins the cluster without problems > before allowing it to run resources. You would set this to "standby" > when deploying the node, and remove the setting once you're satisfied > with the node, so it can run resources at future reboots. So it's mainly intended for initially adding a node? What about a node-global "on_failure=block"? At some point you'l have to try to run resources on your new node, unless it's intended for a quorum-only node. Then failures will cause fencing anyway. Usually modern servers boot slow enough to put the node into standby from the other node before it (the fenced one) rebooted. > > You want a standby setting to last only until the next boot. You would > set this permanently to "online", and any manual setting of standby mode > would be overwritten at the next boot. > > Many thanks to developers Alexandra Zhuravleva and Sergey Mishin, who > contributed this feature as part of a project with EMC. Regards, Ulrich > -- > Ken Gaillot <[email protected]> > > _______________________________________________ > Users mailing list: [email protected] > http://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 _______________________________________________ Users mailing list: [email protected] http://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
