When testing for our next release, our internal tests written by Wing Yew Poon caught a regression in Spark Streaming between 1.2.0 and 1.3.0. The test runs FlumePolling stream to read data from Flume, then kills the Application Master. Once YARN restarts it, the test waits until no more data is to be written and verifies the original against the data on HDFS. This was passing in 1.2.0, but is failing now.
Since the test ties into Cloudera's internal infrastructure and build process, it cannot be directly run on an Apache build. But I have been working on isolating the commit that may have caused the regression. I have confirmed that it was caused by
SPARK-5147 (PR # 4149). I confirmed this several times using the test and the failure is consistently reproducible.
To re-confirm, I reverted just this one commit (and Clock consolidation one to avoid conflicts), and the issue was no longer reproducible.