The way I assured liveness for the YARN installer was to try running "for $x in dataset Metadata.Dataset return $x" via the API. I just polled for a reasonable amount of time (though honestly, thinking about it now, the correct parameter to use for the polling interval is the startup wait time in the parameters file :) ). It's not perfect, but it gives less false positives than just checking ps for processes that look like CCs/NCs.
- Ian. On Mon, Aug 24, 2015 at 5:03 AM, abdullah alamoudi <[email protected]> wrote: > Now that I think about it. Maybe we should provide multiple ways to do > this. A polling mechanism to be used for arbitrary time and a pushing > mechanism on startup. > I am going to start implementation of this and will probably use RMI for > this task both ways (CC to InstallerDriver and InstallerDriver to CC). > > Cheers, > Abdullah. > > On Mon, Aug 24, 2015 at 2:19 PM, abdullah alamoudi <[email protected]> > wrote: > > > So after further investigation, turned out our startup process just > starts > > the CC and NC processes and then make sure the processes are running and > if > > the processes were found to be running, it returns the state of the > cluster > > to be active and the subsequent test commands can start immediately. > > > > This means that the CC could've started but is not yet ready when we try > > to process the next command. To address this, we need a better way to > tell > > when the startup procedure has completed. we can do this by pushing (CC > > informs installer driver when the startup is complete) or polling (The > > installer driver needs to actually query the CC for the state of the > > cluster). > > > > I can do either way so let's vote. My vote goes to the pushing mechanism. > > Thoughts? > > > > On Mon, Aug 24, 2015 at 10:15 AM, abdullah alamoudi <[email protected]> > > wrote: > > > >> This solution turned out to be incorrect. Actually, the test cases when > I > >> build after using the join method never fails but running an actual > asterix > >> instance never succeeds which is quite confusing. > >> > >> I also think that the startup script has a major bug where it might > >> returns before the startup is complete. More on this later...... > >> > >> On Mon, Aug 24, 2015 at 7:48 AM, abdullah alamoudi <[email protected]> > >> wrote: > >> > >>> It is highly unlikely that it is related. > >>> > >>> Cheers, > >>> Abdullah. > >>> > >>> On Mon, Aug 24, 2015 at 5:45 AM, Chen Li <[email protected]> wrote: > >>> > >>>> @Abdullah: Is this issue related to > >>>> https://issues.apache.org/jira/browse/ASTERIXDB-1074? Ian and I plan > to > >>>> look into the details on Monday. > >>>> > >>>> On Sun, Aug 23, 2015 at 10:08 AM, abdullah alamoudi < > [email protected] > >>>> > > >>>> wrote: > >>>> > >>>> > About 3-4 days ago, I was working on the addition of the filesystem > >>>> based > >>>> > feed adapter and it didn't take anytime to complete. However, when I > >>>> wanted > >>>> > to build and make sure all tests pass, I kept getting > >>>> ConnectionRefused > >>>> > errors which caused the installer tests to fail every now and then. > >>>> > > >>>> > I knew the new change had nothing to do with this failure, yet, I > >>>> couldn't > >>>> > direct my attention away from this bug (It just bothered me so much > >>>> and I > >>>> > knew it needs to be resolved ASAP). After wasting countless hours, I > >>>> was > >>>> > finally able to figure out what was happening :-) > >>>> > > >>>> > In the startup routine, we start three Jetty web servers (Web > >>>> interface > >>>> > server, JSON API server, and Feed server). Sometime ago, we used to > >>>> end the > >>>> > startup call before making sure the server.isStarted() method > returns > >>>> true > >>>> > on all servers. At that time, I introduced the waitUntilServerStarts > >>>> method > >>>> > to make sure we don't return before the servers are ready. Turned > >>>> out, that > >>>> > was an incorrect way to handle this (We can blame stackoverflow for > >>>> this > >>>> > one!) and it is not enough that the server isStarted() returns true. > >>>> The > >>>> > correct way to do this is to call the server.join() method after the > >>>> > server.start(). > >>>> > > >>>> > See: > >>>> > > >>>> > http://stackoverflow.com/questions/15924874/embedded-jetty-why-to-use-join > >>>> > > >>>> > This was equally satisfying as it was frustrating and you are > welcome > >>>> for > >>>> > the future time I saved each of you :) > >>>> > -- > >>>> > Amoudi, Abdullah. > >>>> > > >>>> > >>> > >>> > >>> > >>> -- > >>> Amoudi, Abdullah. > >>> > >> > >> > >> > >> -- > >> Amoudi, Abdullah. > >> > > > > > > > > -- > > Amoudi, Abdullah. > > > > > > -- > Amoudi, Abdullah. >
