NOTE: We may introduce backward incompatible changes regarding samza job submission in the future 1.5 release. Details can be found on SEP-23: Simplify Job Runner

We are thrilled to announce the release of Apache Samza 1.4.0.

Today, Samza forms the backbone of hundreds of real-time production applications across a multitude of companies, such as LinkedIn, Slack, and Redfin, among many others. Samza provides leading support for large-scale stateful stream processing with:

  • First class support for local state (with RocksDB store). This allows a stateful application to scale up to 1.1 Million events/sec on a single machine with SSD.
  • Support for incremental checkpointing of state instead of full snapshots. This enables Samza to scale to applications with very large state.
  • A fully asynchronous programming model that makes parallelizing remote calls efficient and effortless.
  • High level API for expressing complex stream processing pipelines in a few lines of code.
  • Beam Samza Runner that marries Beam’s best in class support for EventTime based windowed processing and sophisticated triggering with Samza’s stable and scalable stateful processing model.
  • A fully pluggable model for input sources (e.g. Kafka, Kinesis, DynamoDB streams etc.) and output systems (HDFS, Kafka, ElastiCache etc.).
  • A Table API that provides a common abstraction for accessing remote or local databases and allowing developers are able to “join” an input event stream with such a Table.
  • Flexible deployment model for running the applications in any hosting environment and with cluster managers other than YARN.

New Features, Upgrades and Bug Fixes:

This release brings the following features, upgrades, and capabilities (highlights):

  • Improvements regarding management and monitoring of local state
  • Improvements to the Samza SQL API
  • New system producer for Azure blob storage
  • Bug fixes

Full list of the jiras addressed in this release can be found here.

Upgrading your application to Apache Samza 1.4.0

If an application is being upgraded to Samza 1.4, please note the following usage changes.

  • The samza-autoscaling module is no longer supported, and the module has been removed.


  • SAMZA-2386 Get store names should return correct store names in the presence of side inputs
  • SAMZA-2324 Adding KV store metrics for rocksdb
  • SAMZA-2416 Adding null-check before incrementing metrics for bytesSerialized
  • SAMZA-2397 Samza rocksdb metrics do not emit values after Samza version >= 1.1
  • SAMZA-2447 Checkpoint dir removal should only search in valid store dirs


  • SAMZA-2362 Include the ScalarUDF implementations with the configured package prefix in ReflectionBasedUdfResolver.
  • SAMZA-2375 Samza-sql: Store udf original name for display purposes
  • SAMZA-2376 Samza-sql: Samza sql should handle sql statements with trailing semi-colon (;)
  • SAMZA-2396 Support dynamic addition of jars in ReflectionUdfResolver.
  • SAMZA-2415 Samza-Sql: Fix AvroRelConverter to only consider cached schema while populating SamzaSqlRelRecord for all the nested records.
  • SAMZA-2425 Samza-sql: support subquery in joins
  • SAMZA-2455 Validate the argument types in SamzaSQL UDF on execution planning phase

Azure Bob Storage system producer

  • SAMZA-2421 Add SystemProducer for Azure Blob Storage

Job coordinator dependency isolation (experimental)

  • SAMZA-2421 Add SystemProducer for Azure Blob Storage
  • SAMZA-2332 [AM isolation] YarnJob should pass new command and additional environment variables for AM deployment
  • SAMZA-2333 [AM isolation] Use cytodynamics classloader to launch job coordinator

Bug fixes

  • SAMZA-2334 ProxyGrouper selection based on Host Affinity not whether job is stateful
  • SAMZA-2372 Null pointer exception in LocalApplicationRunner
  • SAMZA-2443 Upgrade Jetty version to prevent AM file descriptor leak
  • SAMZA-2446 Invoke onCheckpoint only for registered SSPs
  • SAMZA-2463 Duplicate firings of processing timers
  • SAMZA-2461 Fix Concurrent Modification Exception in InMemorySystem

Other improvements

  • SAMZA-2364 Include the localized resource lib directory in the classpath of SamzaContainer
  • Clean up unused org.apache.samza.autoscaling module
  • SAMZA-2444 JobModel save in CoordinatorStreamStore resulting flush for each message
  • SAMZA-2452 Adding internal autosizing related configs

Sources downloads

A source download of Samza 1.4.0 is available here, and is also available in Apache’s Maven repository. See Samza’s download page for details and Samza’s feature preview for new features.