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From Matt <dromitl...@gmail.com>
Subject Re: [BUG?] Cannot Load User Class on Local Environment
Date Tue, 25 Apr 2017 20:50:26 GMT
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 <dromitlabs@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.richter@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 <dromitlabs@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

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