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apache / samza / 5e34ec9bf9d486caa464aca1e8bc5ce2a1f780f1
commit5e34ec9bf9d486caa464aca1e8bc5ce2a1f780f1[log] [tgz]
authorJakob Homan <jghoman@apache.org>Wed Jun 25 09:57:41 2014 -0700
committerJakob Homan <jghoman@apache.org>Wed Jun 25 09:57:41 2014 -0700
tree3daf621a0b174d5c4c4990be01e12a7b55456da9
parentaa0e7636c77a5d16e1bbc7c56c1b7e8ed46cae21 [diff]
SAMZA-284: Resolve bundled Kafka jar issue
4 files changed
tree: 3daf621a0b174d5c4c4990be01e12a7b55456da9
  1. docs/
  2. gradle/
  3. samza-api/
  4. samza-core/
  5. samza-kafka/
  6. samza-kv/
  7. samza-serializers/
  8. samza-shell/
  9. samza-test/
  10. samza-yarn/
  11. .gitignore
  12. .reviewboardrc
  13. bootstrap.gradle
  14. build.gradle
  15. DISCLAIMER
  16. gradle.properties
  17. gradlew
  18. HEADER
  19. KEYS
  20. LICENSE
  21. NOTICE
  22. README.md
  23. RELEASE.md
  24. settings.gradle
README.md

What is Samza?

Apache Incubator 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.

  • Simpe API: Unlike most low-level messaging system APIs, Samza provides a very simple call-back based “process message” API that should be familiar to anyone that's used Map/Reduce.
  • Managed state: Samza manages snapshotting and restoration of a stream processor‘s state. Samza will restore a stream processor’s state to a snapshot consistent with the processor's last read messages when the processor is restarted.
  • Fault tolerance: Samza will work with YARN to restart your stream processor if there is a machine or processor failure.
  • Durability: Samza uses Kafka to guarantee that messages will be processed in the order they were written to a partition, and that no messages will ever be lost.
  • Scalability: Samza is partitioned and distributed at every level. Kafka provides ordered, partitioned, re-playable, 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 processor security through 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 or binary release, 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 2.2.0, by default. Use the -PscalaVersion switches to change Scala versions. Samza supports building Scala with 2.9.2, or 2.10.

./gradlew -PscalaVersion=2.9.2 clean build

Testing Samza

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

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

Maven

Samza uses Kafka, which is not managed by Maven. To use Kafka as though it were a Maven artifact, Samza installs Kafka into a local repository using the mvn install command. You must have Maven installed to build Samza.

Developers

To get eclipse projects, run:

./gradlew eclipse

For IntelliJ, run:

./gradlew idea

Pardon our Dust

Apache Samza is currently undergoing incubation at the Apache Software Foundation.