Welcome to Ubik's wiki.

Web site: http://www.sapia-oss.org/projects/ubik/

History

We've been using Ubik in production for a couple of years now. In fact, the project has been started in 2002. What a long way! EJBs were all the rage at that time (but slowly loosing ground to more lightweight approaches).

Anyway, Ubik has been designed for ease of use in mind. It's great for quickly implementing remote services, in a manner that is completely compatible with the "lightweight" philosophy (in fact, with exactly that philosophy in mind).

Ubik offers scalability and reliability without the complexity of JINI and the bloat of an appserver.

• History
• News
• Guice and Ubik
• Tips

News

• 2008-12-11: Added Guice support

Guice and Ubik

The Ubik-Guice integration provides:

• the ability to export (to a Ubik JNDI server) objects instantiated by Guice as Ubik services.
• the ability to inject, as dependencies, remote references looked up from a Ubik JNDI server.

Both of these features have been implemented through specific Guice "providers".

Imagine a distributed app where node A depends on node B. There are potentially a few problems:

1. at the startup of A, B may not yet be available. Typically, this involves the startup of A being aborted.
2. B might want to "appear" on the network at startup, but Ubik's JNDI my not be up at that time.

What's been implemented supports the late-binding of services, through discovery:

1. at the startup of A, if B is not available (or if A cannot find a Ubik JNDI server at this time), a proxy is created for B in order to allow for the proper startup of A. The proxy will automatically discover all instances of B that appear on the network, eventually. Before an instance of B is acquired, the proxy will throw exceptions when invoked.
2. if B attempts to binding itself to Ubik's JNDI but no JNDI server is present, B will place itself in watchdog mode and wait that a Ubik JNDI server appears. When it does, B will bind itslef to it.

Here's a snippet to wet your appetite:

final NamingService naming = new NamingServiceImpl("default")
  .setJndiHost(Localhost.getLocalAddress().getHostAddress())
  .setJndiPort(1099);    

Injector injector = Guice.createInjector(new AbstractModule(){
  
  @Override
  protected void configure() {
    bind(NamingService.class).toInstance(naming);
    bind(TimeServiceIF.class).toProvider(new RemoteServiceExporter<TimeServiceIF>(new TimeServiceImpl(), "services/time"));
  }
  
});

// calling getInstance() internally invokes get() on the RemoteServiceExporter, which publishes the service
// to the JNDI.
TimeServiceIF server = injector.getInstance(TimeServiceIF.class);

System.out.println("Bound time server");
while(true){
  Thread.sleep(10000);
}

See the Javadoc for more info.

Tips

How to start a JNDI Server Programmatically

package org.sapia.ubik.rmi.examples;

import org.sapia.ubik.rmi.naming.remote.EmbeddableJNDIServer;

public class JndiRunner {
  
  public static void main(String[] args) throws Exception{
    
    EmbeddableJNDIServer jndi = new EmbeddableJNDIServer("default", 1099);
    jndi.start(true);
    
    while(true){
      Thread.sleep(100000);
    }
  }
}