buffer-slayer

buffer-slayer is tool that buffers requests and send them in batch, of which client supports batch operation. Such as Spring-JdbcTemplate(batchUpdate), Redis(pipeline).

It has a queue that allows multiple producers to send to, and limited so to keep application away from Overflowing.

Also there is a fixed sized buffer to normalize data transportation. The buffer's data will be sent when it is full or a specific timeout is reached whichever comes first.

This project is inspired by zipkin-reporter-java.

Motivation

Consumer is always faster in batch than accepting one by one.
When consumer is slower than producer, don't overflow application's memory.
If a flood of requests is coming, low down the impact on the backing storage (DB, redis, etc.).
A promise is returned for async sending. Even though messages are sent in batch, you can get a one-to-one promise from the message sent to sending result.

JdbcTemplate

bufferslayer-spring-jdbc is a buffer implementation of Spring's JdbcTemplate.

Queries are forwarded to the delegated JdbcTemplate and executed blockingly.

Updates directly goes to the reporter and returns a Promise immediately.

Quick-start

<dependency>
  <groupId>io.github.tramchamploo</groupId>
  <artifactId>bufferslayer-spring-jdbc</artifactId>
  <version>1.3.6</version>
</dependency>

For native implementation:

<dependency>
  <groupId>io.github.tramchamploo</groupId>
  <artifactId>bufferslayer-boundedqueue</artifactId>
  <version>1.3.6</version>
</dependency>

For rx-java implementation:

<dependency>
  <groupId>io.github.tramchamploo</groupId>
  <artifactId>bufferslayer-rx</artifactId>
  <version>1.3.6</version>
</dependency>

AsyncReporterProperties reporterProperties = new AsyncReporterProperties()
        .setFlushThreads(5)
        .setSenderThreads(10)
        .setBufferedMaxMessages(500)
        .setPendingMaxMessages(10000)
        .setMetrics("inmemory")
        .setMetricsExporter("http");

BatchJdbcTemplate template = new BatchJdbcTemplate(yourFormerJdbcTemplate, reporterProperties);

Promise promise = template.update(...);
promise.done(success -> ...)
       .fail(reject -> ...);

Usage

ReporterProperties

This is where you configure all properties.

sender: Sender that messages are flushed into. Necessary but often not needed for users to configure. Implementations like JdbcTemplate will configure it by itself.
senderThreads: Num of threads that sender execute in.
timerThreads: Num of threads in scheduled executor, flushing messages at a fixed rate.
flushThreads: Num of threads that flush messages to sender. They wait until a buffer is full.
metrics: (inmemory, noop) metrics that records nums of sent, dropped, queued messages.
metricsExporter: (http, log) exporter to let users know data of metrics.
bufferedMaxMessages: Max size of buffer that sent in one batch.
messageTimeoutNanos: If buffer size is not reached, flush will be invoked after this timeout.
pendingMaxMessages: Max size of messages to be stashed until OverflowStrategy is triggered.
pendingKeepaliveNanos: Pending queue should die if no messages queued into during in its keepalive.
overflowStrategy: (DropHead, DropTail, DropBuffer, DropNew, Fail) after pendingMaxMessages is reached, the strategy will be triggered.
singleKey: If this value is true, different kinds of messages will be staged in the same SizeBoundedQueue.

Benchmark

Here is a simple jdbc benchmark result on my MacBook Pro (Retina, 13-inch, Late 2013).

Using mysql 5.7.18, keeps executing a simple INSERT INTO test.benchmark(data, time) VALUES(?, ?);

Benchmark                                                    Mode  Cnt       Score  Units
BatchJdbcTemplateBenchmark.high_contention_batched          thrpt   15   27917.086  ops/s
BatchJdbcTemplateBenchmark.high_contention_unbatched        thrpt   15     316.562  ops/s
BatchJdbcTemplateBenchmark.mild_contention_batched          thrpt   15   18672.057  ops/s
BatchJdbcTemplateBenchmark.mild_contention_unbatched        thrpt   15     280.970  ops/s
BatchJdbcTemplateBenchmark.no_contention_batched            thrpt   15    9053.288  ops/s
BatchJdbcTemplateBenchmark.no_contention_unbatched          thrpt   15     198.581  ops/s

Components

Reporter

It sends requests to a queue and keeps flushing them to consumer.

Sender

Sending the messages that the buffer drained in batch.

SizeBoundedQueue

A queue that bounded by a specific size. Supports multi producers in parallel. It supports overflow strategies as listed.

DropHead: drops the oldest element
DropTail: drops the youngest element
DropBuffer: drops all the buffered elements
DropNew: drops the new element
Block: block offer thread, this can be used as a simple back-pressure strategy
Fail: throws an exception

Strategies above are inspired by Akka stream.

QueueManager

Manages SizeBoundedQueue's lifecycle. Be responsible for queue creation and destruction.

Buffer

A list with a fixed size that can only be drained when a timeout is reached or is full.

shan-ge / buffer-slayer