Actually it looks like the root cause of IMPALA-3367 is not fixed (and maybe never will be?). So running these tests in parallel might just be wishful thinking.

Lars Volker - do you know if IMPALA-2479 (specifically this comment) has been or can be addressed by your scheduler changes?

Henry Robinson - yes, IMPALA-2479 should not happen after this change. The scheduler now takes a copy of the current backend configuration and does round-robin based on that. Concurrent queries and concurrent updates to the scheduler's backend configuration should not interfere with this.

Thanks for confirming, Lars Volker! FWIW I could also not reproduce the issue by running test_runtime_filters.py in a loop with parallelism.

commit 16f1c8d8de0ad33e52524fd4761e7728852c27cc
Author: Alex Behm <alex.behm@cloudera.com>
Date: Wed Aug 31 18:53:32 2016 -0700

IMPALA-4054: Remove serial test workarounds for IMPALA-2479.

The underlying issue IMPALA-2479 has been fixed, so it
should be safe to execute these tests in parallel again:

• test_runtime_filters.py (all tests)
• test_scanners.py::TestParquet::test_multiple_blocks
• test_scanners.py::testParquet::test_multiple_blocks_one_row_group

Testing: Ran the tests locally in a loop. Did a private core/hdfs run.

Change-Id: I8f046e67eb1de1c6ff87980f906870ec9816f551
Reviewed-on: http://gerrit.cloudera.org:8080/4291
Reviewed-by: Tim Armstrong <tarmstrong@cloudera.com>
Reviewed-by: Lars Volker <lv@cloudera.com>
Tested-by: Internal Jenkins