Revelator framework

Revelator is a low latency messages processing framework in Java 17.

Features

• With the original Disruptor design, EventHandler is dealing with each incoming message independently by performing complete piece work over it. With Revelator it is possible to easily handle different processing stages on the same core, depending on how other cores are progressing (relying on relevant memory fences). This design allows to utilize L1 and L2 caches much more efficiently, and avoid unnecessary cache coherency traffic. It is also possible to do as much as possible work when receiving batches of messages - Revelator operates as a Kanban-style processor - refer to the PipelinedFlowProcessor.java for more details.

• A pool of fixed number of parallel message processors does not always work well. Volatile reads contention increases the message processing latency. For latency-critical services, Revelator will offer a more efficient scaling design, where more worker threads can facilitate spikes.

• To combine N multiple fences into a single sequential constraint, Diruptor only has a min-aggregation rule ( SequenceGroup.java), where the handler always makes N volatile reads and then processes all available messages up to a less progressing predecessor. There is no simple way to conditionally wait for specific sequence barriers. For latency-critical services, Revelator offers a more flexible design to improve mean latency - it is possible to define a function that maps message properties (such as account id) into a relevant fence, therefore avoiding unnecessary volatile reads.

• In the Disruptor - message handlers are not batch-aware. There is no way to break a large spike batch into smaller pieces, so that the follower can start catching up earlier, before the batch is completed. The Revelator offers such functionality to provide optimal balance between latency and throughput.

• Revelator will support extended metrics collection. It can be helpful when identifying bottlenecks of the processing pipeline and measuring latency penalties in each processing stage.

Installation

1. Install library into your Maven's local repository by running mvn install
2. Add the following Maven dependency to your project's pom.xml:

<dependency>
    <groupId>exchange.core2</groupId>
    <artifactId>revelator</artifactId>
    <version>0.1.0</version>
</dependency>

Usage examples

TBD

Testing

TBD

Contributing

Revelator is an open-source project and contributions are welcome!