Hi Michael! The only safe way in Java to isolate the user code from the platform would be to completely run them in different JVMs.
Other than that, Max's method to ensure the correct instantiation should work in most cases. We also continuously try to have fewer dependencies in Flink, to that there is less to clash. Stephan On Wed, Jul 20, 2016 at 3:53 PM, Maximilian Michels <m...@apache.org> wrote: > Sure. No Problem. > > The issue is a bit more involved. You're right, the user classes have > precedence over the Flink classpath. So your classes were probably > loaded fine. However, the user code also calls Flink code which can > use a library version different from the job jar library. And boom, it > crashes because the job jar library has been loaded previously :) > > The only way we could circumvent this problem would be to explicitly > set a different classloader and load Flink internal classes via > reflection. I think the performance penalty for this would be way too > high. > > Best, > Max > > On Wed, Jul 20, 2016 at 2:23 PM, Michal Budzyn > <michal.budzyn.ext...@zalando.de> wrote: > > Thanks for the prompt replay. > > > > You are right. The conflict was between "com.fasterxml.jackson.core" > libs. > > > > I am just wondering. If the the jobs were separted from the platform, > > > > the jobs libs should have precedence and no versioning problem should > have > > happened. > > > > Regards, > > > > Michal > > > > > > > > On 20.07.2016 14:00, Maximilian Michels wrote: > >> > >> Hi Michal, > >> > >> I couldn't find Joda in flink-dist. Possibly there is some other clash? > >> > >> There are two potential issues here: > >> > >> 1) Flink shades some libraries (Guava) but not all. If you use a > >> version of a library in your Flink job which doesn't match the one in > >> flink-dist, you're bound for trouble. > >> > >> 2) Flink separates jobs from each other to avoid potential class > >> version mismatches. Each job has its own classloader. In this sense, > >> "job versioning" is supported. > >> > >> Cheers, > >> Max > >> > >> On Wed, Jul 20, 2016 at 1:02 PM, Michal Budzyn > >> <michal.budzyn.ext...@zalando.de> wrote: > >>> > >>> Hi all, > >>> We had a class versioning problem within Flink Job. > >>> The job uses Joda 2.6, but the flink-dist 1.0.3 packages 2.5. > >>> The problem was solved by relocating job classes with shade plug-in. > >>> > >>> Does flink separate jobs from each other to avoid class conflicts > between > >>> them and the platform ? > >>> Is job versioning supported or is shading always required ? > >>> > >>> Regards, > >>> Michal > >>> > > >
