We implement the "context dependent switching" of the execution
environments (cluster / local / test) with static variables in the ExecutionEnvironment. That means that these environments are potentially shared between multiple threads that run programs (also in case where they run one after the other). This may lead to exceptions, as we sometimes see in the tests, when using forked test execution: The later test in the same JVM may access the same environment object as the prior ones. In particular, we see that half finished programs may still be associated with the execution environment, such that mixes between programs occur, producing hard to understand cast exceptions (see trace below) This is so far only relevant to tests with forked execution, but may become relevant to users that build different programs at the same time. I propose to change the static members from environments to environment factories. That way, we can switch type of environment depending on the context as before, and we guarantee that each call to "ExecutionEnvironment.getEnvironment()" returns a dedicated and fresh environment. Running org.apache.flink.api.scala.operators.translation.DistinctTranslationTest java.lang.ClassCastException: org.apache.flink.api.common.operators.base.DeltaIterationBase cannot be cast to org.apache.flink.api.common.operators.base.GroupReduceOperatorBase at org.apache.flink.api.scala.operators.translation.DistinctTranslationTest.testCombinable(DistinctTranslationTest.scala:39) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:483) at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:47) at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12) at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:44) at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17) at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:271) at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:70) at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:50) at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238) at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63) at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236) at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53) at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229) at org.junit.runners.ParentRunner.run(ParentRunner.java:309) at org.apache.maven.surefire.junit4.JUnit4Provider.execute(JUnit4Provider.java:264) at org.apache.maven.surefire.junit4.JUnit4Provider.executeTestSet(JUnit4Provider.java:153) at org.apache.maven.surefire.junit4.JUnit4Provider.invoke(JUnit4Provider.java:124) at org.apache.maven.surefire.booter.ForkedBooter.invokeProviderInSameClassLoader(ForkedBooter.java:200) at org.apache.maven.surefire.booter.ForkedBooter.runSuitesInProcess(ForkedBooter.java:153) at org.apache.maven.surefire.booter.ForkedBooter.main(ForkedBooter.java:103) Tests run: 1, Failures: 1, Errors: 0, Skipped: 0, Time elapsed: 0.027 sec <<< FAILURE! - in org.apache.flink.api.scala.operators.translation.DistinctTranslationTest testCombinable(org.apache.flink.api.scala.operators.translation.DistinctTranslationTest) Time elapsed: 0.024 sec <<< FAILURE! java.lang.AssertionError: org.apache.flink.api.common.operators.base.DeltaIterationBase cannot be cast to org.apache.flink.api.common.operators.base.GroupReduceOperatorBase at org.junit.Assert.fail(Assert.java:88) at org.apache.flink.api.scala.operators.translation.DistinctTranslationTest.testCombinable(DistinctTranslationTest.scala:46) |
+1
Yes, this seems like a very good idea and the Environment is very lightweight, so this would not worsen performance. On Mon, Nov 3, 2014 at 11:19 PM, Stephan Ewen <[hidden email]> wrote: > We implement the "context dependent switching" of the execution > environments (cluster / local / test) with static variables in the > ExecutionEnvironment. > > That means that these environments are potentially shared between multiple > threads that run programs (also in case where they run one after the other). > > This may lead to exceptions, as we sometimes see in the tests, when using > forked test execution: The later test in the same JVM may access the same > environment object as the prior ones. In particular, we see that half > finished programs may still be associated with the execution environment, > such that mixes between programs occur, producing hard to understand cast > exceptions (see trace below) > > This is so far only relevant to tests with forked execution, but may become > relevant to users that build different programs at the same time. > > I propose to change the static members from environments to environment > factories. That way, we can switch type of environment depending on the > context as before, and we guarantee that each call to > "ExecutionEnvironment.getEnvironment()" returns a dedicated and fresh > environment. > > > Running org.apache.flink.api.scala.operators.translation.DistinctTranslationTest > java.lang.ClassCastException: > org.apache.flink.api.common.operators.base.DeltaIterationBase cannot > be cast to org.apache.flink.api.common.operators.base.GroupReduceOperatorBase > at org.apache.flink.api.scala.operators.translation.DistinctTranslationTest.testCombinable(DistinctTranslationTest.scala:39) > at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) > at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) > at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) > at java.lang.reflect.Method.invoke(Method.java:483) > at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:47) > at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12) > at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:44) > at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17) > at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:271) > at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:70) > at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:50) > at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238) > at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63) > at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236) > at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53) > at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229) > at org.junit.runners.ParentRunner.run(ParentRunner.java:309) > at org.apache.maven.surefire.junit4.JUnit4Provider.execute(JUnit4Provider.java:264) > at org.apache.maven.surefire.junit4.JUnit4Provider.executeTestSet(JUnit4Provider.java:153) > at org.apache.maven.surefire.junit4.JUnit4Provider.invoke(JUnit4Provider.java:124) > at org.apache.maven.surefire.booter.ForkedBooter.invokeProviderInSameClassLoader(ForkedBooter.java:200) > at org.apache.maven.surefire.booter.ForkedBooter.runSuitesInProcess(ForkedBooter.java:153) > at org.apache.maven.surefire.booter.ForkedBooter.main(ForkedBooter.java:103) > Tests run: 1, Failures: 1, Errors: 0, Skipped: 0, Time elapsed: 0.027 > sec <<< FAILURE! - in > org.apache.flink.api.scala.operators.translation.DistinctTranslationTest > testCombinable(org.apache.flink.api.scala.operators.translation.DistinctTranslationTest) > Time elapsed: 0.024 sec <<< FAILURE! > java.lang.AssertionError: > org.apache.flink.api.common.operators.base.DeltaIterationBase cannot > be cast to org.apache.flink.api.common.operators.base.GroupReduceOperatorBase > at org.junit.Assert.fail(Assert.java:88) > at org.apache.flink.api.scala.operators.translation.DistinctTranslationTest.testCombinable(DistinctTranslationTest.scala:46) |
+1 as well and nice catch with the exception.
On 03 Nov 2014, at 14:32, Aljoscha Krettek <[hidden email]> wrote: > +1 > > Yes, this seems like a very good idea and the Environment is very > lightweight, so this would not worsen performance. > > On Mon, Nov 3, 2014 at 11:19 PM, Stephan Ewen <[hidden email]> wrote: >> We implement the "context dependent switching" of the execution >> environments (cluster / local / test) with static variables in the >> ExecutionEnvironment. >> >> That means that these environments are potentially shared between multiple >> threads that run programs (also in case where they run one after the other). >> >> This may lead to exceptions, as we sometimes see in the tests, when using >> forked test execution: The later test in the same JVM may access the same >> environment object as the prior ones. In particular, we see that half >> finished programs may still be associated with the execution environment, >> such that mixes between programs occur, producing hard to understand cast >> exceptions (see trace below) >> >> This is so far only relevant to tests with forked execution, but may become >> relevant to users that build different programs at the same time. >> >> I propose to change the static members from environments to environment >> factories. That way, we can switch type of environment depending on the >> context as before, and we guarantee that each call to >> "ExecutionEnvironment.getEnvironment()" returns a dedicated and fresh >> environment. >> >> >> Running org.apache.flink.api.scala.operators.translation.DistinctTranslationTest >> java.lang.ClassCastException: >> org.apache.flink.api.common.operators.base.DeltaIterationBase cannot >> be cast to org.apache.flink.api.common.operators.base.GroupReduceOperatorBase >> at org.apache.flink.api.scala.operators.translation.DistinctTranslationTest.testCombinable(DistinctTranslationTest.scala:39) >> at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) >> at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) >> at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) >> at java.lang.reflect.Method.invoke(Method.java:483) >> at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:47) >> at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12) >> at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:44) >> at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17) >> at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:271) >> at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:70) >> at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:50) >> at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238) >> at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63) >> at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236) >> at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53) >> at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229) >> at org.junit.runners.ParentRunner.run(ParentRunner.java:309) >> at org.apache.maven.surefire.junit4.JUnit4Provider.execute(JUnit4Provider.java:264) >> at org.apache.maven.surefire.junit4.JUnit4Provider.executeTestSet(JUnit4Provider.java:153) >> at org.apache.maven.surefire.junit4.JUnit4Provider.invoke(JUnit4Provider.java:124) >> at org.apache.maven.surefire.booter.ForkedBooter.invokeProviderInSameClassLoader(ForkedBooter.java:200) >> at org.apache.maven.surefire.booter.ForkedBooter.runSuitesInProcess(ForkedBooter.java:153) >> at org.apache.maven.surefire.booter.ForkedBooter.main(ForkedBooter.java:103) >> Tests run: 1, Failures: 1, Errors: 0, Skipped: 0, Time elapsed: 0.027 >> sec <<< FAILURE! - in >> org.apache.flink.api.scala.operators.translation.DistinctTranslationTest >> testCombinable(org.apache.flink.api.scala.operators.translation.DistinctTranslationTest) >> Time elapsed: 0.024 sec <<< FAILURE! >> java.lang.AssertionError: >> org.apache.flink.api.common.operators.base.DeltaIterationBase cannot >> be cast to org.apache.flink.api.common.operators.base.GroupReduceOperatorBase >> at org.junit.Assert.fail(Assert.java:88) >> at org.apache.flink.api.scala.operators.translation.DistinctTranslationTest.testCombinable(DistinctTranslationTest.scala:46) |
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