Resolution: Not A Problem
Affects Version/s: 1.6.3, 1.7.0
Fix Version/s: None
Steps to reproduce:
- Instantiate a MiniAccumuloCluster with at least two tablet servers
- Create a table; add splits to the table.
- Add some mutations to the table distributed across the splits; flush the mutations.
- Create a BatchScanner across the full range of the table.
- Assert that the batch scanner has at least one KV pair by calling scanner.iterator().hasNext()
It doesn't seem to matter if you close the scanner and create a new one in between calls to hasNext, or if you re-seek the same scanner, or if the scanner is created in a static context and re-used by multiple tests or created by each test. Eventually you will see that the TabletServerBatchReaderIterator gets stuck polling its resultsQueue, preventing further tests from running.
This happens roughyl 20% of the time in 1.6 when I run mvn clean test -Dtest=org.apache.accumulo.minicluster.MultipleHasNextTest --projects minicluster, maybe less often in 1.7, and 100% of the time when I try to use the MAC in my company's product build environment, which uses gradle.
(I'll update with a link to a failing unit test as soon as I get an issue ID)