Reactive Relational Database Connectivity Connection Pool Implementation

This project contains a R2DBC connection pool using reactor-pool for reactive connection pooling.

Maven

Both milestone and snapshot artifacts (library, source, and javadoc) can be found in Maven repositories.

<dependency>
  <groupId>io.r2dbc</groupId>
  <artifactId>r2dbc-pool</artifactId>
  <version>1.0.0.BUILD-SNAPSHOT</version>
</dependency>

Artifacts can be found at the following repositories.

Repositories

<repository>
    <id>spring-snapshots</id>
    <name>Spring Snapshots</name>
    <url>https://repo.spring.io/snapshot</url>
    <snapshots>
        <enabled>true</enabled>
    </snapshots>
</repository>

<repository>
    <id>spring-milestones</id>
    <name>Spring Milestones</name>
    <url>https://repo.spring.io/milestone</url>
    <snapshots>
        <enabled>false</enabled>
    </snapshots>
</repository>

Usage

Configuration of the ConnectionPool can be accomplished in two ways:

Connection Factory Discovery

ConnectionFactory connectionFactory = ConnectionFactories.get(ConnectionFactoryOptions.builder()
   .option(DRIVER, "pool")
   .option(PROTOCOL, "h2") // driver identifier, PROTOCOL is delegated as DRIVER by the pool.
   .option(HOST, "…")
   .option(PORT, "…") 
   .option(USER, "…")
   .option(PASSWORD, "…")
   .option(DATABASE, "…")
   .build());

The delegated `DRIVER` (via `PROTOCOL`) above refers to the r2dbc-driver, currently one of `h2`, `postgresql`, `mssql`.

Publisher<? extends Connection> connectionPublisher = connectionFactory.create();

// Alternative: Creating a Mono using Project Reactor
Mono<Connection> connectionMono = Mono.from(connectionFactory.create());

Supported Connection Factory Discovery options:

Option	Description
driver	Must be pool
protocol	Driver identifier. The value is propagated by the pool to the driver property.
maxSize	Maximum pool size. Defaults to 10.
validationQuery	Query that will be executed just before a connection is given to you from the pool to validate that the connection to the database is still alive.

All other properties are driver-specific

Programmatic

ConnectionFactory connectionFactory = …;

ConnectionPoolConfiguration configuration = ConnectionPoolConfiguration.builder(connectionFactory)
   .validationQuery("SELECT 1")
   .maxIdleTime(Duration.ofMillis(1000))
   .maxSize(20)
   .build();

ConnectionPool pool = new ConnectionPool(configuration);
 

Mono<Connection> connectionMono = pool.create();

// later

Connection connection = …;
Mono<Void> release = connection.close(); // released the connection back to the pool

// application shutdown
pool.dispose();

License

This project is released under version 2.0 of the Apache License.