Apache Flink 1.13.6 Release: Bug Fixes, Improvements, and Updated Maven Dependencies

The Apache Flink community has published a new bug‑fix release, Flink 1.13.6. This version contains 99 bug and vulnerability fixes, a minor set of improvements to Flink 1.13, and an upgrade of Apache Log4j to 2.17.1. Users are strongly encouraged to upgrade.

New Maven Dependencies

<dependency>
  <groupId>org.apache.flink</groupId>
  <artifactId>flink-java</artifactId>
  <version>1.13.6</version>
</dependency>
<dependency>
  <groupId>org.apache.flink</groupId>
  <artifactId>flink-streaming-java_2.11</artifactId>
  <version>1.13.6</version>
</dependency>
<dependency>
  <groupId>org.apache.flink</groupId>
  <artifactId>flink-clients_2.11</artifactId>
  <version>1.13.6</version>
</dependency>

Bug Fixes

FLINK-15987 – SELECT 1.0e0 / 0.0e0 throws NumberFormatException.

FLINK-17914 – HistoryServer deletes cached archives when the archive list fails.

FLINK-20195 – Jobs endpoint returns duplicate jobs.

FLINK-20370 – Incorrect results when sink primary key differs from query.

FLINK-21289 – Application mode ignores pipeline.classpaths configuration.

FLINK-23919 – PullUpWindowTableFunctionIntoWindowAggregateRule generates invalid Calc for Window TVF.

FLINK-24232 – Paused job archives prevent subsequent archive attempts after interruption.

FLINK-24255 – Test/minicluster does not forward configuration.

FLINK-24310 – Documentation error in BufferingSink example.

FLINK-24318 – Inconsistent boolean conversion results between SELECT fields and POSITION conditions.

FLINK-24334 – Configuration kubernetes.flink.log.dir has no effect.

FLINK-24366 – Misleading error message when a cancelled job fails to restore.

FLINK-24401 – TM cannot exit after Metaspace OOM.

FLINK-24465 – Incorrect Javadoc and documentation for buffer timeout error.

FLINK-24492 – Wrong implicit type conversion between numeric and (var)char.

FLINK-24506 – Checkpoint directory cannot be configured via Flink config passed to StreamExecutionEnvironment.

FLINK-24509 – FlinkKafkaProducer example fails to compile due to wrong constructor signature.

FLINK-24540 – Fix resource leak caused by Files.list.

FLINK-24543 – Zookeeper connection issues cause state inconsistency in Flink.

FLINK-24563 – Comparing timstamp_ltz with random strings throws NullPointerException.

FLINK-24597 – RocksDBStateBackend getKeysAndNamespaces returns duplicate data when using MapState.

FLINK-24621 – JobManager cannot recover 1.13.1 checkpoints due to InflightDataRescalingDescriptor.

FLINK-24662 – PyFlink Sphinx check fails: node class 'meta' already registered.

FLINK-24667 – Channel state writer fails tasks directly after previous exception.

FLINK-24676 – Schema mismatch when inserting with partial column list.

FLINK-24678 – Correct metric name for map state to include latency.

FLINK-24708 – ConvertToNotInOrInRule produces incorrect results. ConvertToNotInOrInRule FLINK-24728 – Batch SQL sink forgets to close output stream.

FLINK-24761 – Fix compilation failure in PartitionPruner code generation.

FLINK-24846 – AsyncWaitOperator fails during stop‑with‑savepoint.

FLINK-24860 – Fix incorrect position mapping in Python UDTF.

FLINK-24885 – NullPointerException in ProcessElement collector parameter.

FLINK-24922 – Correct spelling error "parallism".

FLINK-25022 – ThreadLocal ClassLoader leak on JobManager when submitting jobs via REST API.

FLINK-25067 – Clarify description of RocksDB background thread.

FLINK-25084 – Field names must be unique; duplicate detection added.

FLINK-25091 – Documentation error for FileSink ORC compression property.

FLINK-25096 – Issues in exception API (/jobs/:jobid/exceptions) for Flink 1.13.2.

FLINK-25199 – StreamEdges not unique in self‑join, blocking watermark propagation.

FLINK-25362 – Incorrect dependency in Table Confluent/Avro documentation.

FLINK-25468 – Local recovery fails when local state store and RocksDB work directory are on different volumes.

FLINK-25486 – Per‑job cannot recover from checkpoint when Zookeeper leader changes.

FLINK-25494 – Duplicate element serializer during DefaultOperatorStateBackendSnapshotStrategy#syncPrepareResources.

FLINK-25513 – CoFlatMapFunction requires two flat_map calls to produce output.

FLINK-25559 – Data loss caused by SQL JOIN.

FLINK-25683 – Incorrect results when converting table to DataStream and then windowing in batch mode.

FLINK-25728 – Potential memory leak in StreamMultipleInputProcessor.

FLINK-25732 – Dispatcher#requestMultipleJobDetails returns non‑serializable collection.

Improvements

FLINK-21407 – Clarify which sources and APIs support which formats.

FLINK-20443 – ContinuousProcessingTimeTrigger does not fire at window end.

FLINK-21467 – Document recommended usage of Bounded{One/Multi}Input.endInput and emphasize repeatability.

FLINK-23842 – Add log messages for reader registration and split requests.

FLINK-24631 – Avoid using labels directly as selectors for deployments and services.

FLINK-24739 – Document requirements for Flink application mode.

FLINK-24987 – Enhance ExternalizedCheckpointCleanup enum.

FLINK-25160 – Clarify documentation: tolerable failure checkpoint count for consecutive failures.

FLINK-25415 – Implement retry for Cassandra connector.

FLINK-25611 – Remove thread‑creation guard from CoordinatorExecutorThreadFactory.

FLINK-25818 – Explain how Kafka Source handles idle partitions when parallelism exceeds partition count.

Technical Debt

FLINK-24740 – Update testcontainers dependency to v1.16.2.

FLINK-24796 – Exclude certain directories (javadocs / node_modules) from CI build artifacts. javadocs / node[_modules] FLINK-25472 – Upgrade to Log4j 2.17.1.

FLINK-25375 – Upgrade Log4j to 2.17.0.

FLINK-25576 – Update com.h2database:h2 to 2.0.206.

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