Hi guys, Any update on this?
Best On Tue, Apr 12, 2016 at 12:46 PM, Niranda Perera <niranda.per...@gmail.com> wrote: > Hi all, > > I have encountered a small issue in the standalone recovery mode. > > Let's say there was an application A running in the cluster. Due to some > issue, the entire cluster, together with the application A goes down. > > Then later on, cluster comes back online, and the master then goes into > the 'recovering' mode, because it sees some apps, workers and drivers have > already been in the cluster from Persistence Engine. While in the recovery > process, the application comes back online, but now it would have a > different ID, let's say B. > > But then, as per the master, application registration logic, this > application B will NOT be added to the 'waitingApps' with the message > ""Attempted to re-register application at same address". [1] > > private def registerApplication(app: ApplicationInfo): Unit = { > val appAddress = app.driver.address > if (addressToApp.contains(appAddress)) { > logInfo("Attempted to re-register application at same address: " + > appAddress) > return > } > > > The problem here is, master is trying to recover application A, which is > not in there anymore. Therefore after the recovery process, app A will be > dropped. However app A's successor, app B was also omitted from the > 'waitingApps' list because it had the same address as App A previously. > > This creates a deadlock in the cluster, app A nor app B is available in > the cluster. > > When the master is in the RECOVERING mode, shouldn't it add all the > registering apps to a list first, and then after the recovery is completed > (once the unsuccessful recoveries are removed), deploy the apps which are > new? > > This would sort this deadlock IMO? > > look forward to hearing from you. > > best > > [1] > https://github.com/apache/spark/blob/master/core/src/main/scala/org/apache/spark/deploy/master/Master.scala#L834 > > -- > Niranda > @n1r44 <https://twitter.com/N1R44> > +94-71-554-8430 > https://pythagoreanscript.wordpress.com/ > -- Niranda @n1r44 <https://twitter.com/N1R44> +94-71-554-8430 https://pythagoreanscript.wordpress.com/