loadbalancing & failover of stateless beans

• Key: OPENEJB-816
• Type: New Feature
• Status: Open
• Priority: Major
• Assignee: Unassigned
• Reporter: Youcef HILEM
• Component/s: general
• Affects Version/s: 3.1.x

Description

Following the exchanges in the mailing-list [e-mail]: "loadbalancing & failover of stateless beans," I ask adding:

- a way to specify a list of URLs as an InitialContext param
- a way to specify the ConnectionFactoryStrategy via an additional InitialContext param
- one ore more conection strategies

Comments

[David Blevins]

These linked issues released in 3.1 solve this request for the most part. It is possible to failover from one server to the next. We don't yet have the ability to feed the server list via a initialcontext parameter -- we should be able to get that in, it was simply overlooked.

If multicast is used a server list will be created automatically and each client on first request which gives a stateless failover where the server list automatically updates as servers come and go from the cluster.

Alternatively, you can now register a new ConnectionFactory by simply including a "META-INF/org.apache.openejb.client.ConnectionFactory/foo" file in your classpath where "foo" is the protocol prefix you wish to control and the file "foo" points to an implementation of org.apache.openejb.client.ConnectionFactory. A basic implementation might look like:

{code}
import java.io.IOException;
import java.net.URI;
import org.apache.openejb.client.ConnectionFactory;
import org.apache.openejb.client.ConnectionManager;

/**
 * Handles any connection requests for URIs that start with "foo:"
 *
 * @version $Rev$ $Date$
 */
public class FooConnectionFactory implements ConnectionFactory {

    /**
     * Get a connection using the URI specified.
     *
     * @param uri in most cases will be the value of "java.naming.provider.url"
     * as specified in the InitialContext parameters
     * @return
     * @throws IOException
     */
    public Connection getConnection(URI uri) throws IOException {
        // Get the URIs from a System property or possibly
        // create some URI format that can be split or expanded
        // into a list of "ejbd:" URIs
        URI[] uris = null;

        for (URI serverURI : uris) {
            // serverURI should be an "ejbd:" or similar URI handleable
            // by the built-in ConnectionFactory implementations.
            return ConnectionManager.getConnection(serverURI);
        }

        throw new IOException("No Server URIs specified");
    }
}
{code}