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apache / samza / release-0.9.0-rc0
tag1039f7ede6490f9420dcecd6adc7677b97e78bcf
taggerYan Fang <yanfang724@gmail.com>Tue Mar 24 14:27:08 2015 -0700
object6b85a1a88216c668442fa7fe7e52dab216f0e858 
Apache Samza 0.9.0 release candidate 0
commit6b85a1a88216c668442fa7fe7e52dab216f0e858[log] [tgz]
authorYan Fang <yanfang724@gmail.com>Tue Mar 24 13:53:34 2015 -0700
committerYan Fang <yanfang724@gmail.com>Tue Mar 24 13:53:34 2015 -0700
tree09fe15130f3d62381f0566c4bbe77e4e190fb05b
parentc91cea5ed9544a84aea9547e4d8e906c4cd321d6 [diff]
SAMZA-613: update 0.9.0 release version
2 files changed
tree: 09fe15130f3d62381f0566c4bbe77e4e190fb05b
  1. bin/
  2. docs/
  3. gradle/
  4. samza-api/
  5. samza-core/
  6. samza-kafka/
  7. samza-kv/
  8. samza-kv-inmemory/
  9. samza-kv-rocksdb/
  10. samza-log4j/
  11. samza-shell/
  12. samza-test/
  13. samza-yarn/
  14. .gitignore
  15. .reviewboardrc
  16. .travis.yml
  17. bootstrap.gradle
  18. build.gradle
  19. doap_Samza.rdf
  20. gradle.properties
  21. gradlew
  22. HEADER
  23. KEYS
  24. LICENSE
  25. NOTICE
  26. README.md
  27. RELEASE.md
  28. settings.gradle
README.md

What is Samza?

Apache Samza is a distributed stream processing framework. It uses Apache Kafka for messaging, and Apache Hadoop YARN to provide fault tolerance, processor isolation, security, and resource management.

Samza's key features include:

  • Simple API: Unlike most low-level messaging system APIs, Samza provides a very simple callback-based “process message” API comparable to MapReduce.
  • Managed state: Samza manages snapshotting and restoration of a stream processor's state. When the processor is restarted, Samza restores its state to a consistent snapshot. Samza is built to handle large amounts of state (many gigabytes per partition).
  • Fault tolerance: Whenever a machine in the cluster fails, Samza works with YARN to transparently migrate your tasks to another machine.
  • Durability: Samza uses Kafka to guarantee that messages are processed in the order they were written to a partition, and that no messages are ever lost.
  • Scalability: Samza is partitioned and distributed at every level. Kafka provides ordered, partitioned, replayable, fault-tolerant streams. YARN provides a distributed environment for Samza containers to run in.
  • Pluggable: Though Samza works out of the box with Kafka and YARN, Samza provides a pluggable API that lets you run Samza with other messaging systems and execution environments.
  • Processor isolation: Samza works with Apache YARN, which supports Hadoop's security model, and resource isolation through Linux CGroups.

Check out Hello Samza to try Samza. Read the Background page to learn more about Samza.

Building Samza

To build Samza from a git checkout, run:

./gradlew clean build

To build Samza from a source release, it is first necessary to download the gradle wrapper script above. This bootstrapping process requires Gradle to be installed on the source machine. Gradle is available through most package managers or directly from its website. To bootstrap the wrapper, run:

gradle -b bootstrap.gradle

After the bootstrap script has completed, the regular gradlew instructions below are available.

Scala and YARN

Samza builds with Scala 2.10 and YARN 2.4.0, by default. Use the -PscalaVersion switches to change Scala versions. Samza supports building Scala with 2.10.

./gradlew -PscalaVersion=2.10 clean build

Testing Samza

Build Status

To run all tests:

./gradlew clean test

To run a single test:

./gradlew clean :samza-test:test -Dtest.single=TestStatefulTask

To run key-value performance tests:

./gradlew samza-shell:kvPerformanceTest -PconfigPath=file://$PWD/samza-test/src/main/resources/perf/kv-perf.properties

To run all integration tests:

./bin/integration-tests.sh <dir>

Job Management

To run a job (defined in a properties file):

./gradlew samza-shell:runJob -PconfigPath=file:///path/to/job/config.properties

To inspect a job's latest checkpoint:

./gradlew samza-shell:checkpointTool -PconfigPath=file:///path/to/job/config.properties

To modify a job's checkpoint (assumes that the job is not currently running), give it a file with the new offset for each partition, in the format systems.<system>.streams.<topic>.partitions.<partition>=<offset>:

./gradlew samza-shell:checkpointTool -PconfigPath=file:///path/to/job/config.properties \
    -PnewOffsets=file:///path/to/new/offsets.properties

Developers

To get Eclipse projects, run:

./gradlew eclipse

For IntelliJ, run:

./gradlew idea

Apache Software Foundation

Apache Samza is a top level project of the Apache Software Foundation.

Apache Software Foundation Logo