Apache Flink 1.5.6 Released

December 26, 2018 -

The Apache Flink community released the sixth and last bugfix version of the Apache Flink 1.5 series.

This release includes more than 47 fixes and minor improvements for Flink 1.5.5. The list below includes a detailed list of all fixes.

We highly recommend all users to upgrade to Flink 1.5.6.

Updated Maven dependencies:


You can find the binaries on the updated Downloads page.

List of resolved issues:



  • [FLINK-8336] - YarnFileStageTestS3ITCase.testRecursiveUploadForYarnS3 test instability
  • [FLINK-9646] - ExecutionGraphCoLocationRestartTest.testConstraintsAfterRestart failed on Travis
  • [FLINK-10166] - Dependency problems when executing SQL query in sql-client
  • [FLINK-10309] - Cancel with savepoint fails with java.net.ConnectException when using the per job-mode
  • [FLINK-10419] - ClassNotFoundException while deserializing user exceptions from checkpointing
  • [FLINK-10455] - Potential Kafka producer leak in case of failures
  • [FLINK-10482] - java.lang.IllegalArgumentException: Negative number of in progress checkpoints
  • [FLINK-10491] - Deadlock during spilling data in SpillableSubpartition
  • [FLINK-10566] - Flink Planning is exponential in the number of stages
  • [FLINK-10581] - YarnConfigurationITCase.testFlinkContainerMemory test instability
  • [FLINK-10642] - CodeGen split fields errors when maxGeneratedCodeLength equals 1
  • [FLINK-10655] - RemoteRpcInvocation not overwriting ObjectInputStream's ClassNotFoundException
  • [FLINK-10669] - Exceptions & errors are not properly checked in logs in e2e tests
  • [FLINK-10670] - Fix Correlate codegen error
  • [FLINK-10674] - Fix handling of retractions after clean up
  • [FLINK-10690] - Tests leak resources via Files.list
  • [FLINK-10693] - Fix Scala EitherSerializer duplication
  • [FLINK-10715] - E2e tests fail with ConcurrentModificationException in MetricRegistryImpl
  • [FLINK-10750] - SocketClientSinkTest.testRetry fails on Travis
  • [FLINK-10752] - Result of AbstractYarnClusterDescriptor#validateClusterResources is ignored
  • [FLINK-10753] - Propagate and log snapshotting exceptions
  • [FLINK-10770] - Some generated functions are not opened properly.
  • [FLINK-10773] - Resume externalized checkpoint end-to-end test fails
  • [FLINK-10821] - Resuming Externalized Checkpoint E2E test does not resume from Externalized Checkpoint
  • [FLINK-10839] - Fix implementation of PojoSerializer.duplicate() w.r.t. subclass serializer
  • [FLINK-10856] - Harden resume from externalized checkpoint E2E test
  • [FLINK-10857] - Conflict between JMX and Prometheus Metrics reporter
  • [FLINK-10880] - Failover strategies should not be applied to Batch Execution
  • [FLINK-10913] - ExecutionGraphRestartTest.testRestartAutomatically unstable on Travis
  • [FLINK-10925] - NPE in PythonPlanStreamer
  • [FLINK-10990] - Enforce minimum timespan in MeterView
  • [FLINK-10998] - flink-metrics-ganglia has LGPL dependency
  • [FLINK-11011] - Elasticsearch 6 sink end-to-end test unstable


  • [FLINK-4173] - Replace maven-assembly-plugin by maven-shade-plugin in flink-metrics
  • [FLINK-9869] - Send PartitionInfo in batch to Improve perfornance
  • [FLINK-10613] - Remove logger casts in HBaseConnectorITCase
  • [FLINK-10614] - Update test_batch_allround.sh e2e to new testing infrastructure
  • [FLINK-10637] - Start MiniCluster with random REST port
  • [FLINK-10678] - Add a switch to run_test to configure if logs should be checked for errors/excepions
  • [FLINK-10906] - docker-entrypoint.sh logs credentails during startup
  • [FLINK-10916] - Include duplicated user-specified uid into error message
  • [FLINK-11005] - Define flink-sql-client uber-jar dependencies via artifactSet


  • [FLINK-10606] - Construct NetworkEnvironment simple for tests
  • [FLINK-10607] - Unify to remove duplicated NoOpResultPartitionConsumableNotifier
  • [FLINK-10827] - Add test for duplicate() to SerializerTestBase