[beam_PostCommit_Java_Nexmark_Dataflow] Several queries are failing

https://builds.apache.org/job/beam_PostCommit_Java_Nexmark_Dataflow/4484/

This test suite has been failing most of the time recently.

 
18:33:14 java.lang.RuntimeException: Execution was not successful*18:33:14* at org.apache.beam.sdk.nexmark.Main.runAll(Main.java:170)18:33:14 at org.apache.beam.sdk.nexmark.Main.main(Main.java:415)18:33:14 18:33:14 >
Task :sdks:java:testing:nexmark:run
FAILED*18:33:14* 18:33:14 FAILURE: Build failed with an exception.18:33:14 18:33:14 * What went wrong:18:33:14 Execution failed for task ':sdks:java:testing:nexmark:run'.18:33:14 > Process 'command '/usr/lib/jvm/java-8-openjdk-amd64/bin/java'' finished with non-zero exit