Hi Tammo, Can you suggest the best method from these to implement? As first I suggested the master-slaves scenario I think it is easy to implement than distributed lock scenario. However if you can suggest one from these two, then I can think about it.
Thank you On 21 May 2015 at 12:40, Sathwik B P <sathwik...@gmail.com> wrote: > With respect to the hotdeployment, > > We can drop the deployment archive onto the deployment folder. Since the > DeploymentPoller are acquiring the distributed lock for the DeploymentUnit, > only one of the nodes will get the lock and initiate the deployment. > DeploymentPollers on other nodes will fail in acquiring the lock and hence > will silently ignore it. > > On Thu, May 21, 2015 at 12:30 PM, Sathwik B P <sathwik...@gmail.com> > wrote: > > > Hi Tammo, > > > > The distributed lock acquisition on the DeploymentUnit should be added to > > both DeploymentWebService and DeploymentPoller. > > > > When a deployment operation is initiated through the > DeploymentWebService, > > The load balancer routes it to any of the available nodes. > > > > On the routed node, the DeploymentWebService acquires the Distributed > > lock. On the remaining nodes the DeploymentPoller will try to acquire the > > distributed lock and will not get it and hence will silently ignore it. > > > > Once the routed node completes the deployment, it will release the lock. > > This way we don't have to stall the DeploymentPoller in other nodes. > > > > Does it answer the concerns? > > > > > > Now, if we give the responsibility of identifying the master node to the > > hazelcast, how do we plan to intimate the load balancer to change it's > > configuration about the master node? > > Assuming there are 3 nodes in the cluster, > > node1 -master > > node2 - slave > > node3 - slave > > > > Node1 goes down, the LB will promote Node2 as master node, but hazelcast > > might promote Node3 as master node. They are out of sync. > > > > Is this argument valid? > > > > regards, > > sathwik > > > > On Wed, May 20, 2015 at 1:51 PM, Tammo van Lessen <tvanles...@gmail.com> > > wrote: > > > >> Hi Sudharma, > >> > >> what do you expect from the "other nodes deployment"? Compilation is not > >> needed since the CBP file is written to the (shared) FS. Registration is > >> also not needed, since it is done via the shared database. So the only > >> thing that might be needed is to tell the engine that there is a new > >> deployment. I'd need to check that. If this is needed, I revert my last > >> statement, then it is perhaps better to just send an event over > Hazelcast > >> to all nodes that the deployment has changed. > >> > >> Best, > >> Tammo > >> > >> On Wed, May 20, 2015 at 10:13 AM, sudharma subasinghe < > >> suba...@cse.mrt.ac.lk > >> > wrote: > >> > >> > Hi Tammo, > >> > > >> > The master node writes meta data. But runtime information must be > >> available > >> > in all nodes.Since the folder is shared, all nodes will see the > >> > availability of a new process. My idea is for master node to write the > >> meta > >> > data and other nodes to just read the meta data and load process.So we > >> need > >> > a small delay between master node deployment and other nodes > deployment. > >> > > >> > Is there anyway to set the delay between master node and slaves until > >> > master node finish the deployment? > >> > > >> > Thank you > >> > Sudharma > >> > > >> > > >> > On 20 May 2015 at 13:01, Tammo van Lessen <tvanles...@gmail.com> > wrote: > >> > > >> > > Hi Sathwik, > >> > > > >> > > On Wed, May 20, 2015 at 6:40 AM, Sathwik B P <sathwik...@gmail.com> > >> > wrote: > >> > > > >> > > > Sudharma/Tammo, > >> > > > > >> > > > 1) How do we plan to decide which is the master node in the > cluster? > >> > > > > >> > > > >> > > I think the easiest approach is to always elect the oldest node in > the > >> > > cluster to be the master. AFAIK Hazelcast can easily asked for this > >> > > information. > >> > > > >> > > > >> > > > >> > > > 2) Don't we need to stall the Deployment Pollers in the slave > nodes? > >> > > > > >> > > > > >> > > Absolutely. > >> > > > >> > > Suggestion: > >> > > > I am not sure whether do we need Master-SLaves. Why not give every > >> node > >> > > in > >> > > > the cluster the same status (Active-Active). > >> > > > > >> > > > When a new deployment is made, the load balancer can push it to > any > >> of > >> > > the > >> > > > available nodes. That node will probably acquire a distributed > lock > >> on > >> > > the > >> > > > deployment unit and acts as master for that deployment. This > ensures > >> > > > optimum usage of the cluster nodes. Probably no static > >> configuration of > >> > > > Master-Slave in the load balancer nor in the hazelcast. > >> > > > > >> > > > >> > > But this would not allow to have the hotdeployment via filesystem > >> still > >> > > enabled, right? > >> > > > >> > > Best, > >> > > Tammo > >> > > > >> > > > >> > > -- > >> > > Tammo van Lessen - http://www.taval.de > >> > > > >> > > >> > >> > >> > >> -- > >> Tammo van Lessen - http://www.taval.de > >> > > > > >
