On Thu, 27 Feb 2020 12:24:46 +0100 "Ulrich Windl" <[email protected]> wrote:
> >>> Jehan-Guillaume de Rorthais <[email protected]> schrieb am 27.02.2020 um > 11:05 in > Nachricht <20200227110502.3624cb87@firost>: > > [...] > > What about something like "lock‑location=bool" and > > For "lock-location" I would assume the value is a "location". I guess you > wanted a "use-lock-location" Boolean value. Mh, maybe "lock-current-location" would better reflect what I meant. The point is to lock the resource on the node currently running it. > > "lock‑location‑timeout=duration" (for those who like automatic steps)? I > > imagine > > I'm still unhappy with "lock-location": What is a "location", and what does it > mean to be "locked"? > Is that fundamentally different from "freeze/frozen" or "ignore" (all those > phrases exist already)? A "location" define where a resource is located in the cluster, on what node. Eg., a location constraint express where a ressource //can// run: «Location constraints tell the cluster which nodes a resource can run on. » https://clusterlabs.org/pacemaker/doc/en-US/Pacemaker/2.0/html/Pacemaker_Explained/_deciding_which_nodes_a_resource_can_run_on.html Here, "constraints" applies to a location. So, if you remove this constraint, the natural definition location would be: «Location tell the cluster what node a resource is running on.» > > it would lock the resource location (unique or clones) until the operator > > unlock it or the "lock‑location‑timeout" expire. No matter what happen to > > the resource, maintenance mode or not. > > > > At a first look, it looks to peer nicely with maintenance‑mode and avoid > > resource migration after node reboot. > > I wonder: Where is it different from a time-limited "ban" (wording also exists > already)? If you ban all resources from running on a specific node, resources > would be move away, and when booting the node, resources won't come back. This is the standby mode. Moreover, note that Ken explicitly wrote: «The cluster runs services that have a preferred node». So if the resource moved elsewhere, the resource **must** come back. > But you want the resources to be down while the node boots, right? How can > that concept be "married with" the concept of high availablility? The point here is to avoid moving resources during planed maintenance/downtime as it would require longer maintenance duration (thus longer downtime) than a simple reboot with no resource migration. Even a resource in HA can have planed maintenance :) > "We have a HA cluster and HA resources, but when we boot a node those > HA-resources will be down while the node boots." How is that different from > not having a HA cluster, or taking those resources temporarily away from the > HA cluster? (That was my intitial objection: Why not simply ignore resource > failures for some time?) Unless I'm wrong, maintenance mode does not secure the current location of resources after reboots. _______________________________________________ Manage your subscription: https://lists.clusterlabs.org/mailman/listinfo/users ClusterLabs home: https://www.clusterlabs.org/
