On 08.06.2022 17:01, Ken Gaillot wrote: > On Wed, 2022-06-08 at 18:31 +0530, Sridhar K wrote: >> Hi Team, >> >> Required guidance w.r.t below problem statement >> >> Need to have a HA setup for SQLServer running as a docker container >> and HA managed by the Pacemaker which is running as a separate docker >> container. >> >> I have done a setup where pacemaker and SQL Server are running as a >> single docker container, able to achieve HA. >> >> How to achieve the same when Pacemaker , and Sqlserver are running in >> different containers. > > I suspect it's not feasible. > > At a minimum, the Pacemaker container needs to run corosync as well as > pacemaker (implying a custom pid 1 script that starts both) and needs > to be privileged. I'm not sure corosync has been successfully > containerized before. > > Bundles won't work because they can only run on Pacemaker nodes. > > The db container could be configured as a remote node, basically > reproducing how a bundle is created internally. The db container would > be configured with pacemaker-remoted as its pid 1, and an IP given to > it that both pacemaker containers can reach. Launching all the > containers would need to be done by the OS at boot or manually. > > An ocf:pacemaker:remote resource would be configured in the cluster to > allow the pacemaker containers to manage the db via pacemaker-remoted > in the db containers. > > A custom fence agent would be needed to allow a pacemaker container to > ask the VM to reboot (kill and relaunch) any other container. Each VM
Actually there is fence_docker which should work in this case. > and VM host would become a single point of failure unless a pacemaker > container could fence the VM and then the host as fallback fence > mechanisms in a topology. > > E.g. try to fence the container -> if that fails, try to fence the VM > -> if that fails, try to fence the host. Without all of that working, > something becomes a single point of failure. > > A preferred setup would be to run corosync and pacemaker on the VMs, > and configure bundles for the db containers. > >> >> Checked remote node,bundle concepts in Pacemaker unable to make HA >> setup work. >> >> Please let me know whether the above scenario can be handled, any >> links, examples would be of great help. >> >> Attaching a picture that depicts the scenario. >> >> Please do the needful, Thank you >> >> Regards >> Sridhar > _______________________________________________ Manage your subscription: https://lists.clusterlabs.org/mailman/listinfo/users ClusterLabs home: https://www.clusterlabs.org/