paluch.biz

Redis Client lettuce 3.2 Final released

This release features Unix domain sockets on linux-x86_64 systems. Local connections to a Redis instance are now possible without the use of the network. A second feature with a huge impact is client options. Client options allow to control behavior on a fine-grained base. It is now possible to turn off auto-reconnect, validate the connection with a PING before activating the connection for client usage and many more.

We tested lettuce using YourKit for performance. Subtracting all IO, the most time is spent on constructing the return futures and command objects. The async API can issue about 300Kops/sec whereas the sync API performs about 13Kops/sec (GET’s, PING’s) on a single thread.
Sync performance depends on the Redis performance (tested on a Mac, 2,7 GHz Intel Core i7).

lettuce provides now also base functionality for building clients using the Redis protocol.
An example is spinach (https://github.com/mp911de/spinach).

lettuce is built with Java 8 but can be used with Java 6, 7 and 8. Java 6 and 7 support will be
dropped with lettuce 4.0. The new lettuce-testcontainer project ensures until then.
You can find the build results at https://travis-ci.org/mp911de/lettuce-testcontainer

If you need any support, meet lettuce at https://gitter.im/mp911de/lettuce

Unix Domain Sockets

Unix Domain Sockets are inter-process communication channels on POSIX compliant systems. They allow to exchange data between processes on the same host operating system. When using Redis, which is usually a network service, Unix Domain Sockets are usable only if connecting locally to a single instance. Redis Sentinel and Redis Cluster,maintain tables of remote or local nodes and act therefore as registry. Unix Domain Sockets are not beneficial with Redis Sentinel and Redis Cluster.
Using RedisClusterClient with Unix Domain Sockets would connect to the local node using a socket and then open TCP connection to all the other hosts. A good example is connecting locally to a standalone or a single cluster node to gain performance.

Unix Domain Socket connections are currently only available to Linux x86_64 systems with a minimum netty version of 4.0.26.Final. You can, however, port the native library to your system. The netty guys would appreciate.

See https://github.com/mp911de/lettuce/wiki/Unix-Domain-Sockets

Enhancements

  • Provide an option to connect to Redis via Unix Domain Sockets #52
  • Add new cluster command MYID #53 (Thanks to @taer)
  • Expose futures of re-subscription on reconnect #62 (Thanks to @kichik)
  • Ping before connect #61 (Thanks to @kichik)
  • Introduce ClientOptions to control specific behavior #58
  • Enhance stability when reconnecting #56
  • Extract and use interfaces for improved extensibility
  • Upgrade netty to 4.0.28.Final

Fixes

  • RedisPubSubConnectionImpl.activated does not call super.activated() #55
  • RedisPubSubConnectionImpl.activated() deadlock #57
  • Fix zrevrangebyscoreWithScores signature bug #65
  • Handle absence of optional epoll library in a reasonable way bug #64

Other

  • Inspect lettuce using YourKit #54

lettuce requires a minimum of Java 8 to build and Java 6 run. It is tested continuously against Redis 3.0.

For complete information on lettuce see the websites:

Links

Maven coordinates:

<dependency>
    <groupId>biz.paluch.redis</groupId>
    <artifactId>lettuce</artifactId>
    <version>3.2.Final</version>
</dependency>

<dependency>
    <groupId>biz.paluch.redis</groupId>
    <artifactId>lettuce</artifactId>
    <version>3.2.Final</version>
    <classifier>shaded</classifier>
</dependency>

Any feedback is appreciated or create issues on GitHub.

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