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| |
| ## What is Samza? |
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| Apache Samza is a distributed stream processing framework. It uses <a target="_blank" href="http://kafka.apache.org">Apache Kafka</a> for messaging, and <a target="_blank" href="http://hadoop.apache.org/docs/current/hadoop-yarn/hadoop-yarn-site/YARN.html">Apache Hadoop YARN</a> to provide fault tolerance, processor isolation, security, and resource management. |
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| * **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. |
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| Check out [Hello Samza](/startup/hello-samza/{{site.version}}) to try Samza. Read the [Background](/learn/documentation/{{site.version}}/introduction/background.html) page to learn more about Samza. |
| |
| ### Apache Software Foundation |
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| Apache Samza is a top level project of the [Apache Software Foundation](http://www.apache.org/). |
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