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Re: [DISCUSS] CloudStack graceful shutdown


Ilya, still regarding the management server that is being shut down issue;
if other MSs/or maybe system VMs (I am not sure to know if they are able to
do such tasks) can direct/redirect/send new jobs to this management server
(the one being shut down), the process might never end because new tasks
are always being created for the management server that we want to shut
down. Is this scenario possible?

That is why I mentioned blocking the port 8250 for the “graceful-shutdown”.

If this scenario is not possible, then everything s fine.


On Wed, Apr 4, 2018 at 7:14 PM, ilya musayev <ilya.mailing.lists@xxxxxxxxx>
wrote:

> I'm thinking of using a configuration from "job.cancel.threshold.minutes" -
> it will be the longest
>
>       "category": "Advanced",
>
>       "description": "Time (in minutes) for async-jobs to be forcely
> cancelled if it has been in process for long",
>
>       "name": "job.cancel.threshold.minutes",
>
>       "value": "60"
>
>
>
>
> On Wed, Apr 4, 2018 at 1:36 PM, Rafael Weingärtner <
> rafaelweingartner@xxxxxxxxx> wrote:
>
> > Big +1 for this feature; I only have a few doubts.
> >
> > * Regarding the tasks/jobs that management servers (MSs) execute; are
> these
> > tasks originate from requests that come to the MS, or is it possible that
> > requests received by one management server to be executed by other? I
> mean,
> > if I execute a request against MS1, will this request always be
> > executed/threated by MS1, or is it possible that this request is executed
> > by another MS (e.g. MS2)?
> >
> > * I would suggest that after we block traffic coming from
> 8080/8443/8250(we
> > will need to block this as well right?), we can log the execution of
> tasks.
> > I mean, something saying, there are XXX tasks (enumerate tasks) still
> being
> > executed, we will wait for them to finish before shutting down.
> >
> > * The timeout (60 minutes suggested) could be global settings that we can
> > load before executing the graceful-shutdown.
> >
> > On Wed, Apr 4, 2018 at 5:15 PM, ilya musayev <
> ilya.mailing.lists@xxxxxxxxx
> > >
> > wrote:
> >
> > > Use case:
> > > In any environment - time to time - administrator needs to perform a
> > > maintenance. Current stop sequence of cloudstack management server will
> > > ignore the fact that there may be long running async jobs - and
> terminate
> > > the process. This in turn can create a poor user experience and
> > occasional
> > > inconsistency  in cloudstack db.
> > >
> > > This is especially painful in large environments where the user has
> > > thousands of nodes and there is a continuous patching that happens
> around
> > > the clock - that requires migration of workload from one node to
> another.
> > >
> > > With that said - i've created a script that monitors the async job
> queue
> > > for given MS and waits for it complete all jobs. More details are
> posted
> > > below.
> > >
> > > I'd like to introduce "graceful-shutdown" into the systemctl/service of
> > > cloudstack-management service.
> > >
> > > The details of how it will work is below:
> > >
> > > Workflow for graceful shutdown:
> > >   Using iptables/firewalld - block any connection attempts on 8080/8443
> > (we
> > > can identify the ports dynamically)
> > >   Identify the MSID for the node, using the proper msid - query
> async_job
> > > table for
> > > 1) any jobs that are still running (or job_status=“0”)
> > > 2) job_dispatcher not like “pseudoJobDispatcher"
> > > 3) job_init_msid=$my_ms_id
> > >
> > > Monitor this async_job table for 60 minutes - until all async jobs for
> > MSID
> > > are done, then proceed with shutdown
> > >     If failed for any reason or terminated, catch the exit via trap
> > command
> > > and unblock the 8080/8443
> > >
> > > Comments are welcome
> > >
> > > Regards,
> > > ilya
> > >
> >
> >
> >
> > --
> > Rafael Weingärtner
> >
>



-- 
Rafael Weingärtner