Re: [systemd-devel] Behavior of BindsTo when stopping a service
On Sun, Jan 28, 2018 at 5:04 PM Andrei Borzenkov wrote: > 28.01.2018 02:11, Amit Saha пишет: > > On Sun, 28 Jan 2018 at 6:22 am, Andrei Borzenkov > > wrote: > > > >> 26.01.2018 05:11, Amit Saha пишет: > >>> Hello, > >>> > >>> I have a systemd service - drainconnections which I want to to make > sure > >>> finishes stopping before systemd starts stopping another service. What > I > >>> also want is to if I stop supervisord service, drainconnections should > be > >>> stopped first. > >>> > >>> It seems like BindsTo is what I need for establishing the coupling > >> between > >>> the two units. > >> > >> If your description of services relationship is accurate and complete, > >> BindsTo is too strong here; you really need just PartsOf. > > > > > > Thanks. PartOf looks like something more suitable. Would having PartOf in > > supervisord obey the before after relationship setup by drainconnections > > service? > > > > PartsOf (like BindsTo) is orthogonal to After/Before. PartsOf/BindsTo > define what to do, After/Before define when to do. > > > I will give it a shot. > Thanks. Tried it and that is how it works. > > > >> > >> > >>> The following unit file describes drainconnections: > >>> > >>> > >>> [Unit] > >>> Description=Drain Connections > >>> After=supervisord.service > >>> BindsTo=supervisord.service > >>> > ... > >>> > >>> In addition, I also needed to add BindsTo=drainconnections to the > >>> supervisord service. > >>> > >> > >> This will create dependency loop with your unit definition shown above. > > > > > > Wouldn’t the Before/After take care of breaking the dependency loop? That > > seems to be what I observed. > > > > Probably I had to elaborate. If you need full BindsTo semantic (which is > superset of Requires) it only works as documented if you also have > corresponding After/Before which creates loop. Otherwise Requires part > is mostly useless. If you are only interested in propagating stop > request and "stopping on surprise removal" part of BindsTo then this is > probably OK, but this will make your units definitions rather confusing. > Thanks, I think your suggestion of using PartOf is more suitable for my use case here - which is basically making sure that I can do some work before systemd shuts down the system (killing supervisord) and use After/Before to ensure the when. This is my current unit file: [Unit] Description=Drain Connections After=supervisord.service PartOf=supervisord.service [Service] Type=oneshot RemainAfterExit=True ExecStart=/bin/true ExecStop=/usr/bin/touch /var/shuttingdown1 ExecStop=/usr/bin/sleep 60 ExecStop=/usr/bin/touch /var/shuttingdown2 [Install] WantedBy=multi-user.target It looks like I added the BindsTo=drainconnectins.service to supervisord as well for a use case where during shutdown, if supervisord was stopped first, it would first stop drainconnections.service. But I don't need that - since systemd figures out it needs to first stop drainconnections.service before it stops supervisord. I think the only change I would make to the supervisord configuration is so that it always starts drainconnections.service when it's started. ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] Behavior of BindsTo when stopping a service
28.01.2018 02:11, Amit Saha пишет: > On Sun, 28 Jan 2018 at 6:22 am, Andrei Borzenkov > wrote: > >> 26.01.2018 05:11, Amit Saha пишет: >>> Hello, >>> >>> I have a systemd service - drainconnections which I want to to make sure >>> finishes stopping before systemd starts stopping another service. What I >>> also want is to if I stop supervisord service, drainconnections should be >>> stopped first. >>> >>> It seems like BindsTo is what I need for establishing the coupling >> between >>> the two units. >> >> If your description of services relationship is accurate and complete, >> BindsTo is too strong here; you really need just PartsOf. > > > Thanks. PartOf looks like something more suitable. Would having PartOf in > supervisord obey the before after relationship setup by drainconnections > service? > PartsOf (like BindsTo) is orthogonal to After/Before. PartsOf/BindsTo define what to do, After/Before define when to do. > I will give it a shot. > >> >> >>> The following unit file describes drainconnections: >>> >>> >>> [Unit] >>> Description=Drain Connections >>> After=supervisord.service >>> BindsTo=supervisord.service >>> ... >>> >>> In addition, I also needed to add BindsTo=drainconnections to the >>> supervisord service. >>> >> >> This will create dependency loop with your unit definition shown above. > > > Wouldn’t the Before/After take care of breaking the dependency loop? That > seems to be what I observed. > Probably I had to elaborate. If you need full BindsTo semantic (which is superset of Requires) it only works as documented if you also have corresponding After/Before which creates loop. Otherwise Requires part is mostly useless. If you are only interested in propagating stop request and "stopping on surprise removal" part of BindsTo then this is probably OK, but this will make your units definitions rather confusing. ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] Behavior of BindsTo when stopping a service
On Sun, 28 Jan 2018 at 6:22 am, Andrei Borzenkov wrote: > 26.01.2018 05:11, Amit Saha пишет: > > Hello, > > > > I have a systemd service - drainconnections which I want to to make sure > > finishes stopping before systemd starts stopping another service. What I > > also want is to if I stop supervisord service, drainconnections should be > > stopped first. > > > > It seems like BindsTo is what I need for establishing the coupling > between > > the two units. > > If your description of services relationship is accurate and complete, > BindsTo is too strong here; you really need just PartsOf. Thanks. PartOf looks like something more suitable. Would having PartOf in supervisord obey the before after relationship setup by drainconnections service? I will give it a shot. > > > > The following unit file describes drainconnections: > > > > > > [Unit] > > Description=Drain Connections > > After=supervisord.service > > BindsTo=supervisord.service > > > > [Service] > > Type=oneshot > > RemainAfterExit=True > > ExecStart=/bin/true > > I think recent sytsemd relaxes requirement, so you can omit ExecStart here. Thanks. > > > > ExecStop=/usr/bin/touch /var/shuttingdown1 > > ExecStop=/usr/bin/sleep 60 > > ExecStop=/usr/bin/touch /var/shuttingdown2 > > > > [Install] > > WantedBy=multi-user.target > > > > > > In addition, I also needed to add BindsTo=drainconnections to the > > supervisord service. > > > > This will create dependency loop with your unit definition shown above. Wouldn’t the Before/After take care of breaking the dependency loop? That seems to be what I observed. > > > Things work as desired for me considering the above configuration. > > > > Am I on the right track here? Thanks in advance. > > > > Best Wishes, > > Amit. > > > > > > > > ___ > > systemd-devel mailing list > > systemd-devel@lists.freedesktop.org > > https://lists.freedesktop.org/mailman/listinfo/systemd-devel > > > > ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/systemd-devel
Re: [systemd-devel] Behavior of BindsTo when stopping a service
26.01.2018 05:11, Amit Saha пишет: > Hello, > > I have a systemd service - drainconnections which I want to to make sure > finishes stopping before systemd starts stopping another service. What I > also want is to if I stop supervisord service, drainconnections should be > stopped first. > > It seems like BindsTo is what I need for establishing the coupling between > the two units. If your description of services relationship is accurate and complete, BindsTo is too strong here; you really need just PartsOf. > The following unit file describes drainconnections: > > > [Unit] > Description=Drain Connections > After=supervisord.service > BindsTo=supervisord.service > > [Service] > Type=oneshot > RemainAfterExit=True > ExecStart=/bin/true I think recent sytsemd relaxes requirement, so you can omit ExecStart here. > ExecStop=/usr/bin/touch /var/shuttingdown1 > ExecStop=/usr/bin/sleep 60 > ExecStop=/usr/bin/touch /var/shuttingdown2 > > [Install] > WantedBy=multi-user.target > > > In addition, I also needed to add BindsTo=drainconnections to the > supervisord service. > This will create dependency loop with your unit definition shown above. > Things work as desired for me considering the above configuration. > > Am I on the right track here? Thanks in advance. > > Best Wishes, > Amit. > > > > ___ > systemd-devel mailing list > systemd-devel@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/systemd-devel > ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/systemd-devel
[systemd-devel] Behavior of BindsTo when stopping a service
Hello, I have a systemd service - drainconnections which I want to to make sure finishes stopping before systemd starts stopping another service. What I also want is to if I stop supervisord service, drainconnections should be stopped first. It seems like BindsTo is what I need for establishing the coupling between the two units. The following unit file describes drainconnections: [Unit] Description=Drain Connections After=supervisord.service BindsTo=supervisord.service [Service] Type=oneshot RemainAfterExit=True ExecStart=/bin/true ExecStop=/usr/bin/touch /var/shuttingdown1 ExecStop=/usr/bin/sleep 60 ExecStop=/usr/bin/touch /var/shuttingdown2 [Install] WantedBy=multi-user.target In addition, I also needed to add BindsTo=drainconnections to the supervisord service. Things work as desired for me considering the above configuration. Am I on the right track here? Thanks in advance. Best Wishes, Amit. ___ systemd-devel mailing list systemd-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/systemd-devel
