# Cassandra

From the [Apache Cassandra](https://cassandra.apache.org/) website:

The database is the right choice when you need scalability and high availability without compromising performance. [Linear scalability](http://techblog.netflix.com/2011/11/benchmarking-cassandra-scalability-on.html) and proven fault-tolerance on commodity hardware or cloud infrastructure make it the perfect platform for mission-critical data. Cassandra’s support for replicating across multiple datacenters is best-in-class, providing lower latency for your users and the peace of mind of knowing that you can survive regional outages.

From [Wikipedia](https://en.wikipedia.org/wiki/Apache_Cassandra):

Apache Cassandra is a free and open-source, distributed, wide-column store, NoSQL database management system designed to handle large amounts of data across many commodity servers, providing high availability with no single point of failure. Cassandra offers support for clusters spanning multiple datacenters,\[2] with asynchronous masterless replication allowing low latency operations for all clients. Cassandra was designed to implement a combination of Amazon’s Dynamo distributed storage and replication techniques combined with Google’s Bigtable data and storage engine model.\[3]

### Cassandra Support in Hop

Hop supports Cassandra 4 (since version 2.2.0) with the following:

#### Metadata Types

* [Cassandra Connection](/data-shaper-1.21/knowing-the-data-shaper-designer/index-2/cassandra-connection.md): Create a connection to your Cassandra database cluster.

#### Workflow Actions

* [Cassandra Exec CQL](/data-shaper-1.21/knowing-the-data-shaper-designer/workflows/actions/cassandra-exec-cql.md): Execute Cassandra [CQL](https://cassandra.apache.org/doc/latest/cql/)

#### Pipeline Transforms

* [Cassandra Input](/data-shaper-1.21/knowing-the-data-shaper-designer/pipelines/transforms/cassandra-input.md): Reads from a Cassandra cluster through a CQL query.
* [Cassandra Output](/data-shaper-1.21/knowing-the-data-shaper-designer/pipelines/transforms/cassandra-output.md): Write data to a table in a Cassandra cluster.
* [SSTable Output](/data-shaper-1.21/knowing-the-data-shaper-designer/pipelines/transforms/sstable-output.md): Write data to a filesystem directory as a Cassandra SSTable.


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