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ReplicatedSpace - 10 years later

· 2 min read
Alejandro Revilla

/by apr/

10 years ago I add an experimental ReplicatedSpace implementation to the jPOS-EE project. While it was fun to develop and test, it didn't get too much traction (or so I thought).

It turned out that I've started to hear about several high-end production systems using it, so I migrated it from the old GoogleCode repo to the new Github one.

Want to give it a quick try? Here are the very simple instructions:

Clone de jPOS-Template into a test directory​

git clone https://github.com/jpos/jPOS-template.git rspace && cd rspace

Edit build.gradle​

Add the dependency compile "org.jpos.ee:jposee-rspace:2.0.9-SNAPSHOT", your dependencies will look like this:

    dependencies {
      compile ('org.jpos:jpos:2.0.+') {
        exclude(module: 'junit')
        exclude(module: 'hamcrest-core')
      }
      testCompile 'junit:junit:4.8.2'
      compile "org.jpos.ee:jposee-rspace:2.0.9-SNAPSHOT"
    }

Install resources​

Call gradle installResources

This will extract the ReplicatedSpace configuration from its jar and will place it in your src/dist directory

Remove the file src/dist/deploy/01_multi_instance_prevention.xml so that you can run multiple instances on the same machine

Build a distribution​

    gradle dist

This will create a build/distributions/rspace-2.0.0.tar.gz that you can extract in several boxes. For a quick local run, you can gradle installApp and cd build/install/rspace to have the same effect.

Run the system​

Call bin/q2 and you'll see something like this:

    <log realm="org.jpos.space.ReplicatedSpaceAdaptor" at="Thu Jun 04 15:18:17.406 UYT 2015" lifespan="1ms">
      <info>
       view-accepted
       [apr-19136|0] (1) [apr-19136]
     </info>
    </log>

If you run it again, or in a different box in the same LAN, you'll see several view-accepted messages.

At this point, you can create a little script to perform some space operations, i.e:

    import org.jpos.space.*;
    Space sp = SpaceFactory.getSpace("rspace:rspace");
    sp.out ("TEST", "REPLICATED MESSAGE");

A nice way to run a script is to deploy something like this:

Add a file called say 90_script.xml to your deploy directory:

    <script> server(6666); </script>

Then telnet localhost 6667 (please note the server says '6666' but you connect to 6666+1, this is BeanShell stuff.

At the bsh% prompt, you can type your space operations.