Scylla Java Driver for Scylla and Apache Cassandra®¶
If you’re reading this on github.com, please note that this is the readme for the development version and that some features described here might not yet have been released. You can find the documentation for the latest version through the Java driver docs or via the release tags, e.g. 18.104.22.168.
A modern, feature-rich and highly tunable Java client library for Apache Cassandra (2.1+) and using exclusively Cassandra’s binary protocol and Cassandra Query Language v3.
The Scylla Java Driver is a fork from DataStax Java Driver, including some non-breaking changes for Scylla optimization, with more updates planned.
Like all Scylla Drivers, the Scylla Java Driver is Shard Aware and contains extensions for a
tokenAwareHostPolicy. Using this policy, the driver can select a connection to a particular shard based on the shard’s token. As a result, latency is significantly reduced because there is no need to pass data between the shards.
Asynchronous IO, parallel execution, request pipelining
Auto node discovery
Works with any cluster size
The driver architecture is based on layers. At the bottom lies the driver core. This core handles everything related to the connections to a Cassandra cluster (for example, connection pool, discovering new nodes, etc.) and exposes a simple, relatively low-level API on top of which higher level layers can be built.
The driver contains the following modules:
driver-core: the core layer.
driver-mapping: the object mapper.
driver-extras: optional features for the Java driver.
driver-examples: example applications using the other modules which are only meant for demonstration purposes.
driver-tests: tests for the java-driver.
SCYLLA UNIVERSITY JAVA CLASS
DOCS: the manual has quick start material and technical details about the driver and its features.
GITHUB REPOSITORY: https://github.com/scylladb/java-driver
Getting the driver¶
The last release of the driver is available on Maven Central. You can install it in your application using the following Maven dependency
<dependency> <groupId>com.scylladb</groupId> <artifactId>scylla-driver-core</artifactId> <version>22.214.171.124</version> </dependency>
Note that the object mapper is published as a separate artifact:
<dependency> <groupId>com.scylladb</groupId> <artifactId>scylla-driver-mapping</artifactId> <version>126.96.36.199</version> </dependency>
The ‘extras’ module is also published as a separate artifact:
<dependency> <groupId>com.scylladb</groupId> <artifactId>scylla-driver-extras</artifactId> <version>188.8.131.52</version> </dependency>
We also provide a shaded JAR to avoid the explicit dependency to Netty.
The Java client driver 184.108.40.206 (branch 3.x) is compatible with Apache Cassandra 2.1, 2.2 and 3.0+.
UDT and tuple support is available only when using Apache Cassandra 2.1 or higher.
Other features are available only when using Apache Cassandra 2.0 or higher (e.g. result set paging, lightweight transactions)
The java driver supports Java JDK versions 6 and above.
Disclaimer: Some Scylla products might partially work on big-endian systems, but Scylla does not officially support these systems.
Upgrading from previous versions¶
If you are upgrading from a previous version of the driver, be sure to have a look at the upgrade guide.
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© 2016, The Apache Software Foundation.
Apache®, Apache Cassandra®, Cassandra®, the Apache feather logo and the Apache Cassandra® Eye logo are either registered trademarks or trademarks of the Apache Software Foundation in the United States and/or other countries. No endorsement by The Apache Software Foundation is implied by the use of these marks.