Hi Till, Great! Do you know if it's planned to be included in v1.2.x or should we wait for v1.3? I'll give it a try as soon as it's merged.
You're right about this approach launching a mini cluster on each Ignite node. That is intentional, as described in my previous message on the list [1]. The idea is to collocate Flink jobs on Ignite nodes, so each dataflow only processes the elements stored on the local in-memory database. I get the impression this should be much faster than randomly picking a Flink node and sending all the data over the network. Any insight on this? Cheers, Matt [1] http://apache-flink-user-mailing-list-archive.2336050.n4.nabble.com/Flink-on-Ignite-Collocation-td12780.html On Thu, Apr 27, 2017 at 5:33 AM, Till Rohrmann <trohrm...@apache.org> wrote: > I just copied my response because my other email address is not accepted > on the user mailing list. > > Hi Matt, > > I think Stefan's analysis is correct. I have a PR open [1], where I fix > the issue with the class loader. > > As a side note, by doing what you're doing, you will spawn on each Ignite > node a new Flink mini cluster. These mini cluster won't communicate with > each other and run independently. Is this what you intend to do? > > [1] https://github.com/apache/flink/pull/3781 > > Cheers, > Till > > On Wed, Apr 26, 2017 at 11:12 PM, Matt <dromitl...@gmail.com> wrote: > >> Let's wait for Till then, I hope he can figure this out. >> >> On Wed, Apr 26, 2017 at 11:03 AM, Stefan Richter < >> s.rich...@data-artisans.com> wrote: >> >>> Ok, now the question is also about what classloaders Ignite is creating >>> and how they are used, but the relevant code line in Flink is probably in >>> FlinkMiniCluster.scala, line 538 (current master): >>> >>> try { >>> JobClient.submitJobAndWait( >>> clientActorSystem, >>> configuration, >>> leaderRetrievalService, >>> jobGraph, >>> timeout, >>> printUpdates, >>> this.getClass.getClassLoader()) >>> } finally { >>> if(!useSingleActorSystem) { >>> // we have to shutdown the just created actor system >>> shutdownJobClientActorSystem(clientActorSystem) >>> } >>> } >>> >>> >>> This is what is executed as part of executing a job through >>> LocalEnvironment. As we can see, the classloader is set to the classloader >>> of FlinkMiniCluster. Depending on the classloader structure inside Ignite, >>> this classloader might not know your user code. What you could do is >>> changing this line in a custom Flink build, changing line 538 for example >>> to Thread.currentThread().getContextClassloader() and ensuring that the >>> context classloader ins the runnable is a classloader that a) knows the >>> user code and b) is a child of the classloader that knows the Ignite and >>> Flink classes. Notice that this is not a general solution and should not >>> become a general fix. >>> >>> I have heard that Till is about to change some things about local >>> execution, so I included him in CC. Maybe he can provide additional hints >>> how your use case might be better supported in the upcoming Flink 1.3. >>> >>> Best, >>> Stefan >>> >>> Am 25.04.2017 um 22:50 schrieb Matt <dromitl...@gmail.com>: >>> >>> I updated the code a little bit for clarity, now the line #56 mentioned >>> in my previous message is line #25. >>> >>> In summary the error I'm getting is this: >>> >>> --- >>> Caused by: org.apache.flink.streaming.runtime.tasks.StreamTaskException: >>> Cannot load user class: com.test.Test >>> ClassLoader info: URL ClassLoader: >>> Class not resolvable through given classloader. >>> --- >>> >>> But if I'm not wrong, after trying to load the class through >>> URLClassLoader, Flink should try loading it with its parent ClassLoader, >>> which should be the same ClassLoader that executed the environment, and it >>> does have access to the class. >>> >>> Not sure what is wrong. >>> >>> On Tue, Apr 25, 2017 at 5:38 PM, Matt <dromitl...@gmail.com> wrote: >>> >>>> Hi Stefan, >>>> >>>> Check the code here: https://gist.github.com/ >>>> 17d82ee7dd921a0d649574a361cc017d , the output is at the bottom of the >>>> page. >>>> >>>> Here are the results of the additional tests you mentioned: >>>> >>>> 1. I was able to instantiate an inner class (Test$Foo) inside the >>>> Ignite closure, no problem with that >>>> 2. I tried implementing SourceFunction and SinkFunction in Test itself, >>>> I was able to instantiate the class inside the Ignite closure >>>> 3. I'm not sure what you meant in this point, is it something like what >>>> I tried in line #56? >>>> >>>> Additionally, I tried implementing the SourceFunction and SinkFunction >>>> in Test$Foo with the same result: it says "Cannot load user class: >>>> com.test.Test$Foo" >>>> >>>> Looks like Flink is not using the correct ClassLoader. Any idea? >>>> >>>> Regards, >>>> Matt >>>> >>>> On Tue, Apr 25, 2017 at 7:00 AM, Stefan Richter < >>>> s.rich...@data-artisans.com> wrote: >>>> >>>>> Hi, >>>>> >>>>> I would expect that the local environment picks up the class path from >>>>> the code that launched it. So I think the question is what happens behind >>>>> the scenes when you call ignite.compute().broadcast(runnable); . >>>>> Which classes are shipped and how is the classpath build in the >>>>> environment >>>>> that runs the code. Your example is also not fully conclusive, because >>>>> com.myproj.Test (which you can successfully instantiate) and >>>>> com.myproj.Test$1$2 (which fails) are different classes, so maybe only the >>>>> outer class is shipped with the broadcast call. My theory is that not all >>>>> classes are shipped (e.g. inner classes), but only Test . You could try >>>>> three things to analyze to problem a little more: >>>>> >>>>> 1) Create another inner class inside Test and try if you are still >>>>> able to instantiate also this class via reflection. >>>>> 2) Let Test class itself implement the map function (avoiding the >>>>> usage of other/inner classes) and see if this works. >>>>> 3) Check and set the thread’s context classloader inside the runnable >>>>> to something that contains all required classes and see if this gets >>>>> picked >>>>> up by Flink. >>>>> >>>>> Best, >>>>> Stefan >>>>> >>>>> Am 25.04.2017 um 07:27 schrieb Matt <dromitl...@gmail.com>: >>>>> >>>>> Hi all, >>>>> >>>>> I'm trying to run Flink using a local environment, but on an Ignite >>>>> node to achieve collocation (as mentioned in my previous message on this >>>>> list). >>>>> >>>>> Have a look at the code in [1]. It's pretty simple, but I'm getting a >>>>> "cannot load user class" error as shown in [2]. >>>>> >>>>> If you check line #29 on the code, I'm able to create an instance of >>>>> class Test, and it's the same context from which I'm creating the Flink >>>>> job. Shouldn't it work provided I'm using a local environment? >>>>> >>>>> It would be really nice to be able to inject a ClassLoader into the >>>>> chunk of code that creates the job. Is this currently possible? >>>>> >>>>> Any fix or workaround is appreciated! >>>>> >>>>> Best, >>>>> Matt >>>>> >>>>> [1] https://gist.github.com/f248187b9638023b95ba8bd9d7f06215 >>>>> [2] https://gist.github.com/796ee05425535ece1736df7b1e884cce >>>>> >>>>> >>>>> >>>> >>> >>> >> >
