On 08/03/2015 12:08 PM, Vijay Partha wrote: > Hi > > For this question: Is it possible to control even for multiple instances of > apache? like i have node 1 running 2 instances of apache and another node > running 1 instance in apache. If my apache server goes down will all these > instances be restarted?
What do you mean by instances? If you're using a single configuration directory such as /etc/httpd, then chances are it's a single instance from pacemaker's point of view, regardless of how many processes apache spawns or how many websites it serves. > Could you give me an example on how this can work. I mean commands that > will make the above case pass. > > Thanking You. > > On Wed, Jul 29, 2015 at 10:34 AM, Vijay Partha <vijaysarath...@gmail.com> > wrote: > >> fine will have a look at it. thank you so much. >> On 29 Jul 2015 22:56, "Ken Gaillot" <kgail...@redhat.com> wrote: >> >>> On 07/29/2015 09:24 AM, Vijay Partha wrote: >>>> could you give an idea on how active active could be achieved? >>> >>> Clusters From Scratch gives a simple walk-through of active/active. See >>> >>> http://clusterlabs.org/doc/en-US/Pacemaker/1.1-pcs/html-single/Clusters_from_Scratch/index.html >>> >>> The basic components are: >>> >>> 1. Fencing >>> >>> 2. Shared storage (DRBD in the walk-through, or could be a SAN or NAS, >>> etc.) >>> >>> 3. Clustered file system (GFS2 in the walk-through) and optionally CLVM >>> (if you want to use logical volumes with shared storage); these often >>> require DLM (distributed lock manager) as well >>> >>> 4. Your service (apache in this case) >>> >>> 5. Some type of load balancer (multicast Ethernet in the walk-through, >>> although something like haproxy is more often used in production) >>> >>>> On 29 Jul 2015 19:52, "Ken Gaillot" <kgail...@redhat.com> wrote: >>>> >>>>> On 07/29/2015 09:03 AM, Vijay Partha wrote: >>>>>> Thanks a lot Ken. for the second case whatever you said , is it >>> possible >>>>> to >>>>>> control even for multiple instances of apache? like i have node 1 >>>>> running 2 >>>>>> instances of apache and another node running 1 instance in apache. If >>> my >>>>>> apache server goes down will all these instances be restarted? >>>>> >>>>> It depends on how you have those instances linked together. >>>>> >>>>> If they're independent -- one node runs www.A.com and another node >>> runs >>>>> api.A.com -- then there's no coordination necessary. Each can be >>>>> monitored, stopped and started independently of the other. >>>>> >>>>> If your goal is to do active-passive failover (if the node serving >>>>> www.A.com goes down, apache is started on another node), then >>> pacemaker >>>>> will handle that automatically. >>>>> >>>>> If your goal is to do active-active load-balancing (every node can >>> serve >>>>> requests to www.A.com simultaneously), that's a more complicated >>>>> configuration, but pacemaker can do it. >>>>> >>>>> In any of the cases, it's generally not necessary to restart apache on >>>>> all nodes. If it's not working on one node, it can be restarted there. >>>>> You can manually disable and reenable the service if you want to force >>> a >>>>> restart everywhere. >>>>> >>>>>> On Wed, Jul 29, 2015 at 7:26 PM, Ken Gaillot <kgail...@redhat.com> >>>>> wrote: >>>>>> >>>>>>> On 07/29/2015 08:05 AM, Vijay Partha wrote: >>>>>>>> Hi. >>>>>>>> >>>>>>>> Victor, Whatever you said i had tried and got it working. Thank you. >>>>>>>> >>>>>>>> Could you guys answer the following questions please? >>>>>>>> >>>>>>>> 1.) I have 2 apache services running on the same node. If the >>> services >>>>> go >>>>>>>> down can pacemaker restart it? >>>>>>> >>>>>>> Yes, that's what pacemaker is for :) >>>>>>> >>>>>>> If by two services you mean two server instances of apache, then you >>>>>>> would configure two apache resources in pacemaker. If you mean two >>> web >>>>>>> apps running in one apache server, you'd configure one apache >>> resource >>>>>>> in pacemaker. >>>>>>> >>>>>>> You would also need a monitor operation, which tells pacemaker to >>>>>>> periodically check the health of the service. >>>>>>> >>>>>>> The migration-threshold and on-fail options determine what the >>> cluster >>>>>>> does on failure. See the documentation for possible values, but the >>>>>>> default behavior is to try to restart the service on the same node. >>>>>>> >>>>>>> The documentation for all the options is at >>>>>>> >>>>>>> >>>>> >>> http://clusterlabs.org/doc/en-US/Pacemaker/1.1-pcs/html-single/Pacemaker_Explained/index.html >>>>>>> >>>>>>>> 2.) I have 2 apache services running on different nodes. Can i >>> control >>>>>>> both >>>>>>>> the resources from a single node by making use of pacemaker? >>>>>>> >>>>>>> The various cluster tools work from any node, to affect any or all >>>>>>> nodes. Most commonly you'd use one of the high-level cluster shells >>>>>>> (crmsh or pcs). They have commands to enable/disable a resource, >>> move a >>>>>>> resource to a different node, put a node in standby mode, etc. _______________________________________________ Users mailing list: Users@clusterlabs.org http://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