HA-JNDI

Rationale

Load balancing and failover.

Current

The suggested functionality can be implemented currently as follows:

  $remotespecs= array('xp://jboss01.example.com/', 'xp://jboss02.example.com/');
  shuffle($remotespecs);
  foreach ($remotespecs as $remotespec) {
    try(); {
      $remote= &Remote::forName($remotespec);
    } if (catch('RemoteException', $e)) {
      continue;
    }

    $e= NULL;
    break;
  }
  
  if ($e) {
    $e->printStackTrace();
    exit(1);
  }
  
  $home= &$remote->lookup('xp/demo/IteratorDemo');

Proposed

The new functionality would make this transparent, so one would not have to differ whether there are one or many remoting servers:

  try(); {
    $remote= &Remote::forName('xp://jboss01.example.com/,xp://jboss02.example.com/');
  } if (catch('RemoteException', $e)) {
    $e->printStackTrace();
    exit(1);
  }

  $home= &$remote->lookup('xp/demo/IteratorDemo');

Notes

• Initially, a random value is used to determine which one of the given servers the connection should be made to. This is not real load- balancing!

• If connecting to jboss01 fails, jboss02 will be used (the other way around respectively).

n/a

- Minimalistic for round-robbing load balancing

n/a

- http://unittests.xp-framework.net/?net.xp_framework.unittest.remote.RemoteTest Unittest verifying new functionality

- friebe, Mon Jun 26 10:33:49 CEST 2006 More ideas using Remote::forName():

  Remote::forName(array('xp://jboss01.example.com/', 'xp://jboss02.example.com/'));
  Remote::forName('xp://jboss01.example.com/', 'xp://jboss02.example.com/');
  Remote::forName('xp+ha://jboss01.example.com,jboss02.example.com');
  Remote::forName('xp://[jboss01.example.com,jboss02.example.com]');

- friebe, Mon Jun 26 11:19:24 CEST 2006 Maybe an extra flag could be added as follows:

  Remote::forName('xp://jboss01.example.com/?master', 'xp://jboss02.example.com/?failover');

In this case, no random value would be used - rather, the connection would always go to jboss01, and only if that fails, jboss02 would be used.

- friebe, Fri Jun 30 09:48:25 2006 Initial implementation comitted, needs further testing but should be available soon.

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