Redisson Sync Context for Maven Resolver

Note: This component is still considered to be experimental, use with caution!

The Redisson Sync Context Factory is a Redisson-based distributed locks factory for Maven Resolver on top of Redis to provide a fast, concurrent-safe access from one or multiple Maven instances to the same local Maven repository.

For further details about the factory read the Javadoc.

Open Issues/Notes

It only works when dependency injection is used and not the bundled AetherModule or ServiceLocator (Maven uses dependency injection).
It includes a lot of trace logging which partially will go way as soon as it has been stabilized.
Usage from plugins has not been tested yet.
The furnace-maven-plugin does not work this implementation because it uses ServiceLocator instead of dependency injection.

Installation/Testing

Create the directory ${maven.home}/lib/ext/redisson/.
Modify ${maven.home}/bin/m2.conf by adding load ${maven.home}/lib/ext/redisson/*.jar right after the ${maven.conf}/logging line.

Copy the following dependencies from Maven Central to ${maven.home}/lib/ext/redisson/:

  ├── byte-buddy-1.10.7.jar
  ├── cache-api-1.0.0.jar
  ├── jackson-annotations-2.11.1.jar
  ├── jackson-core-2.11.1.jar
  ├── jackson-databind-2.11.1.jar
  ├── jackson-dataformat-yaml-2.11.1.jar
  ├── javax.annotation-api-1.3.2.jar
  ├── jboss-marshalling-2.0.9.Final.jar
  ├── jboss-marshalling-river-2.0.9.Final.jar
  ├── jodd-bean-5.0.13.jar
  ├── jodd-core-5.0.13.jar
  ├── maven-resolver-synccontext-redisson-1.6.2.jar
  ├── netty-buffer-4.1.51.Final.jar
  ├── netty-codec-4.1.51.Final.jar
  ├── netty-codec-dns-4.1.51.Final.jar
  ├── netty-common-4.1.51.Final.jar
  ├── netty-handler-4.1.51.Final.jar
  ├── netty-resolver-4.1.51.Final.jar
  ├── netty-resolver-dns-4.1.51.Final.jar
  ├── netty-transport-4.1.51.Final.jar
  ├── reactive-streams-1.0.3.jar
  ├── reactor-core-3.3.4.RELEASE.jar
  ├── redisson-3.13.3.jar
  ├── rxjava-2.2.19.jar
  └── snakeyaml-1.26.jar

Start your Redis instance on localhost or configure a remote instance with ${maven.conf}/maven-resolver-redisson.yaml.
Now start a multithreaded Maven build on your project.

Debugging

Add/modify the following entries in ${maven.home}/conf/logging/simplelogger.properties:

org.slf4j.simpleLogger.showDateTime=true
org.slf4j.simpleLogger.showThreadName=true
org.slf4j.simpleLogger.showShortLogName=true
org.slf4j.simpleLogger.log.org.eclipse.aether.synccontext=trace
#org.slf4j.simpleLogger.log.org.redisson=debug
#org.slf4j.simpleLogger.log.io.netty=debug

Now start a multithreaded Maven build on your project and you should see at least these lines:

# This line does not appear for the default configuration
2316 [main] [TRACE] RedissonSyncContextFactory - Reading Redisson config file from '${maven.conf}/maven-resolver-redisson.yaml'
4626 [main] [TRACE] RedissonSyncContextFactory - Created Redisson client with id '1c8db59b-7939-4014-8506-ae841c74608c'
...
35318 [main] [TRACE] RedissonSyncContextFactory - Shutting down Redisson client with id '1c8db59b-7939-4014-8506-ae841c74608c'

Configuration Options

Option	Type	Description	Default Value
`aether.syncContext.redisson.configFile`	String	Path to a Redisson configuration file in YAML format. Read official documentation for details.	`${maven.conf}/maven-resolver-redisson.yaml`
`aether.syncContext.redisson.discriminator`	String	A discriminator uniquely identifying a host and repository pair. If the generation of the default value fails, it will use `sha1('')`.	`sha1('${hostname:-localhost}:${maven.repo.local}')`

Set Configuration from Apache Maven

To set one of the configuration options from above just use system variables.