Yes Chetan, I am claiming that :-) I still don't understand the need for having two step checkpointing in LocalMode by default.
StramLocalCluster should simplify test execution environment as pointed out by Thomas. Async checkpoint should have its own test cases using StramLocalCluster that should not break when new features are added to the platform. But by default I think StramLocalCluster should use synchronous checkpointing. -Chandni On Thu, Sep 3, 2015 at 2:43 PM, Chetan Narsude <[email protected]> wrote: > Changing the storage agent is one of the ways to address the symptoms of > the problem. But it's not treating the problem. > > In this case - change the basePath to a location under target and all the > opinions are moot. And someone is claiming that we should not do it. Not > sure why. Or is anyone claiming that anymore? > > -- > Chetan > > On Thu, Sep 3, 2015 at 1:43 PM, Thomas Weise <[email protected]> > wrote: > >> Good point regarding the coverage. These JUnit tests are supposed to test >> individual components and all the tests collectively should strive to >> achieve high coverage. There are tests in Apex to cover storage agents, >> recovery semantics etc. Components that fall outside of the test scope >> are >> reduced as much as possible through mocks (even though there is room for >> improvement). >> >> The tests in Malhar are for operators and applications, not for the >> engine. >> In those cases where LM is used, the intention is to test the application >> functionality. It is expected that certain configurations are adjusted for >> the test and dependencies mocked. >> >> For the local mode, it should not be an issue to use a different storage >> agent when it simplifies the test execution. Specifically, in this case, >> we >> don't want to go and change many tests to make something work that isn't >> needed. LM is not "production", it is not using HDFS and there are a >> number >> of other important differences that make it possible to run within the >> IDE. >> >> Instead, focus should be on those things that help with app coverage. For >> example, in the past we had seen issues with serialization of operators >> that were not uncovered in LM, until we made the serialization part of the >> execution, even when it was not needed for execution. >> >> Thomas >> >> >> >> >> On Thu, Sep 3, 2015 at 11:21 AM, Chetan Narsude <[email protected]> >> wrote: >> >> > I think Ram explained in a little more detail on what I am thinking. >> > >> > Tests are supposed to provide code coverage. Having localcluster is >> already >> > a variable, it's not what runs in production. Having a different storage >> > agent is another variable and it misses out on testing the asynchronous >> > flow. The gap keeps on increasing if we continue to do that. AsyncFSSA >> is >> > our default because it's supposed to do everything that FSStorageAgent >> does >> > and some more. So not clear as to why the test which creates stray >> folders >> > is not configuring the storage agent properly instead of completely >> > changing it out which brings some other problems in as I just explained. >> > >> > If changing the storage agent is the only way to fix the problem with >> > reasonable effort, then I would concede. I highly doubt that. >> > >> > -- >> > Chetan >> > >> > On Thu, Sep 3, 2015 at 11:05 AM, Chandni Singh <[email protected] >> > >> > wrote: >> > >> > > The local mode was so far using FSStorageAgent which was used in >> > > production. >> > > In production using Async is needed because hdfs writes are slow but >> is >> > > that the case with LocalMode? >> > > >> > > In local mode if we use Async we are creating checkpoints under one >> local >> > > directory and then copying it to another local directory which will >> not >> > > improve any performance. >> > > >> > > In my opinion StramLocalCluster use synchronous checkpointing as >> default. >> > > >> > > Chandni >> > > >> > > >> > > >> > > On Thu, Sep 3, 2015 at 10:09 AM, Chetan Narsude < >> [email protected]> >> > > wrote: >> > > >> > >> That sounds a lot like self contradicting reason; Let's make a change >> > >> because we don't want to make change. :-) >> > >> >> > >> The code is in certain state. This certain state is consistent with >> how >> > >> things run in production. In test environment there is a problem that >> > stray >> > >> files are created. It's a small fix to relocate these files >> elsewhere. >> > What >> > >> I am trying to understand is that is not being done? >> > >> >> > >> -- >> > >> Chetan >> > >> >> > >> On Thu, Sep 3, 2015 at 9:41 AM, Thomas Weise <[email protected] >> > >> > >> wrote: >> > >> >> > >>> There is no need to configure anything extra with the proposed >> change, >> > it >> > >>> just brings back LM to how it worked before. >> > >>> >> > >>> There is no point modifying n tests for extra setup with no gain. >> > >>> >> > >>> Thomas >> > >>> >> > >>> On Thu, Sep 3, 2015 at 9:14 AM, Chetan Narsude < >> [email protected] >> > > >> > >>> wrote: >> > >>> >> > >>> > Why does it matter that AsyncFSStorageAgent is being used with >> > >>> > LocalCluster? It using the localfs and hence no gain is the >> > >>> implementation >> > >>> > detail that's abstracted out by FileSystem already. >> > >>> > >> > >>> > If there is a problem of random artifacts left behind after the >> test, >> > >>> there >> > >>> > is a reason and most likely it's misconfiguration of the >> > StorageAgent. >> > >>> Why >> > >>> > wouldn't that be fixed. >> > >>> > >> > >>> > -- >> > >>> > Chetan >> > >>> > >> > >>> > >> > >>> > On Thu, Sep 3, 2015 at 8:59 AM, Amol Kekre <[email protected]> >> > >>> wrote: >> > >>> > >> > >>> > > Clean up container files left over should be a distributed OS >> task. >> > >>> Clean >> > >>> > > up, back up, archive, ... all is for the OS (aka YARN). We must >> > >>> assume >> > >>> > kill >> > >>> > > -9. >> > >>> > > >> > >>> > > The only thing where the operator comes into play is >> "teardown()", >> > >>> which >> > >>> > is >> > >>> > > business logic (not Apex engine) issue. This could be db >> connection >> > >>> etc. >> > >>> > > >> > >>> > > Thks, >> > >>> > > Amol >> > >>> > > >> > >>> > > On Thu, Sep 3, 2015 at 8:52 AM, Thomas Weise < >> > [email protected] >> > >>> > >> > >>> > > wrote: >> > >>> > > >> > >>> > > > When the container gets killed, we should not assume anything >> > about >> > >>> > > > cleanup. It can be a kill -9. Any related "cleanup" falls >> under >> > >>> nice to >> > >>> > > > have, no guarantees. >> > >>> > > > >> > >>> > > > On Thu, Sep 3, 2015 at 8:49 AM, Chandni Singh < >> > >>> [email protected] >> > >>> > > >> > >>> > > > wrote: >> > >>> > > > >> > >>> > > > > I have a question regarding what Gaurav mentioned >> > >>> > > > > ---- >> > >>> > > > > When container runs in cluster, "." specifies the containers >> > >>> local >> > >>> > path >> > >>> > > > on >> > >>> > > > > the node where container specific jars and other resources >> > >>> resides. >> > >>> > It >> > >>> > > > > creates a folder under that which is live as long as >> container >> > >>> lives. >> > >>> > > So >> > >>> > > > > there are no vagrant folders anywhere >> > >>> > > > > --- >> > >>> > > > > >> > >>> > > > > When the container gets killed, do we cleanup the folders >> > >>> created by >> > >>> > > > Async >> > >>> > > > > under the containers working dir? >> > >>> > > > > >> > >>> > > > > On Thu, Sep 3, 2015 at 8:42 AM, Thomas Weise < >> > >>> [email protected] >> > >>> > > >> > >>> > > > > wrote: >> > >>> > > > > >> > >>> > > > >> It makes sense to use the synchronous checkpointing for the >> > >>> local >> > >>> > > mode. >> > >>> > > > >> LM is meant to simplify dependencies and setup. The default >> > for >> > >>> > > > execution >> > >>> > > > >> on YARN remains async. >> > >>> > > > >> >> > >>> > > > >> Thomas >> > >>> > > > >> >> > >>> > > > >> >> > >>> > > > >> On Thu, Sep 3, 2015 at 8:34 AM, Chandni Singh < >> > >>> > > [email protected]> >> > >>> > > > >> wrote: >> > >>> > > > >> >> > >>> > > > >>> APPLICATION_PATH isn't related to local base dir of Async >> as >> > >>> far >> > >>> > as I >> > >>> > > > >>> know. StramLocalCluster sets the APP_PATH to "target/...". >> > >>> > > > >>> StramLocalCluster should use FSStorageAgent. >> > >>> > > > >>> >> > >>> > > > >>> - Chandni >> > >>> > > > >>> >> > >>> > > > >>> On Thu, Sep 3, 2015 at 8:20 AM, Gaurav Gupta < >> > >>> > [email protected] >> > >>> > > > >> > >>> > > > >>> wrote: >> > >>> > > > >>> >> > >>> > > > >>>> As Thomas mentioned as default remains to be async. You >> can >> > >>> either >> > >>> > > > >>>> change the storage agent or set the APPLICATION_PATH. >> > >>> > > > >>>> >> > >>> > > > >>>> When container runs in cluster, "." specifies the >> containers >> > >>> local >> > >>> > > > path >> > >>> > > > >>>> on the node where container specific jars and other >> > resources >> > >>> > > > resides. It >> > >>> > > > >>>> creates a folder under that which is live as long as >> > container >> > >>> > > lives. >> > >>> > > > So >> > >>> > > > >>>> there are no vagrant folders anywhere >> > >>> > > > >>>> >> > >>> > > > >>>> Thanks >> > >>> > > > >>>> -Gaurav >> > >>> > > > >>>> >> > >>> > > > >>>> On Wed, Sep 2, 2015 at 11:33 PM, Chandni Singh < >> > >>> > > > [email protected] >> > >>> > > > >>>> > wrote: >> > >>> > > > >>>> >> > >>> > > > >>>>> I think there is a problem in the default Async as >> well. It >> > >>> also >> > >>> > > uses >> > >>> > > > >>>>> the working directory as its local base path. >> > >>> > > > >>>>> >> > >>> > > > >>>>> In the Async -> copyToHdfs() method, we delete the >> window >> > >>> files >> > >>> > > but >> > >>> > > > >>>>> the folder with the operator name never gets deleted. >> > >>> > > > >>>>> So on the cluster there will be such vagrant folders in >> > the >> > >>> > > working >> > >>> > > > >>>>> directory? >> > >>> > > > >>>>> >> > >>> > > > >>>>> On Wed, Sep 2, 2015 at 11:17 PM, Thomas Weise < >> > >>> > > > [email protected]> >> > >>> > > > >>>>> wrote: >> > >>> > > > >>>>> >> > >>> > > > >>>>>> Chandni, >> > >>> > > > >>>>>> >> > >>> > > > >>>>>> Agreed. See whether the tests work with the synchronous >> > >>> storage >> > >>> > > > >>>>>> agent. If yes, change them. The default needs to remain >> > >>> async. >> > >>> > > > >>>>>> >> > >>> > > > >>>>>> Thomas >> > >>> > > > >>>>>> >> > >>> > > > >>>>>> >> > >>> > > > >>>>>> On Wed, Sep 2, 2015 at 11:05 PM, Chandni Singh < >> > >>> > > > >>>>>> [email protected]> wrote: >> > >>> > > > >>>>>> >> > >>> > > > >>>>>>> Hi, >> > >>> > > > >>>>>>> >> > >>> > > > >>>>>>> I would like to know what was the reason to use >> > >>> > > AsyncFSStorageAgent >> > >>> > > > >>>>>>> with StramLocalCluster? >> > >>> > > > >>>>>>> StramLocalCluster is mainly for testing in a >> > >>> non-distributed >> > >>> > mode >> > >>> > > > >>>>>>> and I am unclear how AsyncFSStorageAgent is helpful in >> > this >> > >>> > mode. >> > >>> > > > >>>>>>> >> > >>> > > > >>>>>>> Thanks, >> > >>> > > > >>>>>>> Chandni >> > >>> > > > >>>>>>> >> > >>> > > > >>>>>>> On Wed, Sep 2, 2015 at 10:45 PM, Chandni Singh < >> > >>> > > > >>>>>>> [email protected]> wrote: >> > >>> > > > >>>>>>> >> > >>> > > > >>>>>>>> This is because of recent changes to >> StramLocalCluster >> > >>> where >> > >>> > > > >>>>>>>> AsyncFSStorageAgent is used for checkpointing >> > >>> > > > >>>>>>>> >> > >>> > > > >>>>>>>> dag.setAttribute(OperatorContext.STORAGE_AGENT, new >> > >>> > > > AsyncFSStorageAgent(new Path(pathUri, >> > >>> > > > LogicalPlan.SUBDIR_CHECKPOINTS).toString(), null)); >> > >>> > > > >>>>>>>> >> > >>> > > > >>>>>>>> The AsyncFSStorageAgent(String path, Configuration >> conf) >> > >>> uses >> > >>> > > "." >> > >>> > > > as localBasePath and therefore creates sub-directories per >> > >>> operator in >> > >>> > > the >> > >>> > > > current working directory. >> > >>> > > > >>>>>>>> >> > >>> > > > >>>>>>>> I am going to create a ticket to address this and >> will >> > >>> fix it. >> > >>> > > > >>>>>>>> >> > >>> > > > >>>>>>>> -Chandni >> > >>> > > > >>>>>>>> >> > >>> > > > >>>>>>>> >> > >>> > > > >>>>>>>> On Wed, Sep 2, 2015 at 7:13 PM, Chandni Singh < >> > >>> > > > >>>>>>>> [email protected]> wrote: >> > >>> > > > >>>>>>>> >> > >>> > > > >>>>>>>>> Hi, >> > >>> > > > >>>>>>>>> >> > >>> > > > >>>>>>>>> I can see empty folders getting created under >> > Malhar/lib >> > >>> > called >> > >>> > > > >>>>>>>>> '1' and '2'. >> > >>> > > > >>>>>>>>> I think this is because of using LocalMode to run a >> > test >> > >>> > > > >>>>>>>>> application. >> > >>> > > > >>>>>>>>> >> > >>> > > > >>>>>>>>> >> > >>> > > > >>>>>>>>> If anyone has checked in such cases please do check >> and >> > >>> let >> > >>> > us >> > >>> > > > >>>>>>>>> know. >> > >>> > > > >>>>>>>>> >> > >>> > > > >>>>>>>>> Thanks, >> > >>> > > > >>>>>>>>> Chandni >> > >>> > > > >>>>>>>>> >> > >>> > > > >>>>>>>> >> > >>> > > > >>>>>>>> >> > >>> > > > >>>>>>> >> > >>> > > > >>>>>> >> > >>> > > > >>>>> >> > >>> > > > >>>> >> > >>> > > > >>> >> > >>> > > > >> >> > >>> > > > > >> > >>> > > > >> > >>> > > >> > >>> > >> > >>> >> > >> >> > >> >> > > >> > >> > >
