com.bigdata.service.jini
Class MetadataServer

java.lang.Object
  com.bigdata.service.jini.AbstractServer
      com.bigdata.service.jini.DataServer
          com.bigdata.service.jini.MetadataServer

All Implemented Interfaces:

Runnable, EventListener, net.jini.lease.LeaseListener, net.jini.lookup.ServiceIDListener

public class MetadataServer
extends DataServer

A metadata server.

The metadata server is used to manage the life cycles of scale-out indices and exposes proxies for read and write operations on indices to clients. Clients use index proxies, which automatically direct reads and writes to the IDataService on which specific index partitions are located.

On startup, the metadata service discovers active data services configured in the same group. While running, it tracks when data services start and stop so that it can (re-)allocate index partitions as necessary.

Version:

$Id$

Author:

Bryan Thompson

TODO:

should destroy destroy the service instance or the persistent state as well? Locally, or as replicated?

Nested Class Summary

static class	MetadataServer.AdministrableMetadataService Adds jini administration interfaces to the basic MetadataService.
static interface	MetadataServer.Options Options for this server.

Nested classes/interfaces inherited from class com.bigdata.service.jini.DataServer

DataServer.AdministrableDataService

Nested classes/interfaces inherited from class com.bigdata.service.jini.AbstractServer

AbstractServer.ConfigurationOptions, AbstractServer.MasterElectionTask

Field Summary

Fields inherited from class com.bigdata.service.jini.AbstractServer

config, impl, logicalServiceZPath, physicalServiceZPath, proxy

Constructor Summary

MetadataServer(String[] args, com.sun.jini.start.LifeCycle lifeCycle)

Method Summary

static void	main(String[] args) Starts a new MetadataServer.
protected MetadataService	newService(Properties properties) This method is responsible for creating the remote service implementation object.

Methods inherited from class com.bigdata.service.jini.AbstractServer

destroy, fatal, getClient, getFileFilter, getHostName, getJoinManager, getProxy, getServiceID, getServiceName, isPersistent, isShuttingDown, notify, notifyServiceUUID, readServiceId, run, runDestroy, serviceIDNotify, setSecurityManager, shutdownNow, terminate, toString, unexport

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

MetadataServer

public MetadataServer(String[] args,
                      com.sun.jini.start.LifeCycle lifeCycle)

Parameters:

args - Either the command line arguments or the arguments from the ServiceDescriptor. Either way they identify the jini Configuration (you may specify either a file or URL) and optional overrides for that Configuration.

lifeCycle - The life cycle object. This is used if the server is started by the jini ServiceStarter. Otherwise specify a FakeLifeCycle.

Method Detail

main

public static void main(String[] args)

Starts a new MetadataServer. This can be done programmatically by executing

    new MetadataServer(args,new FakeLifeCycle()).run();
 

within a Thread.

Parameters:

args - The name of the Configuration file for the service.

newService

protected MetadataService newService(Properties properties)

Description copied from class: DataServer

This method is responsible for creating the remote service implementation object. This object MUST declare one or more interfaces that extent the Remote interface. The server will use JERI to create a proxy for the remote object and configure and manage the protocol for communications between the client (service proxy) and the remote object (the service implementation).

Note: You have to implement JoinAdmin in order to show up as an administerable service (blue folder) in the jini Service Browser.

Overridden to setup a delegate that let's us customize some of the federation behaviors on the behalf of the data service.

Overrides:

newService in class DataServer

Parameters:

properties - The contents of the Properties file whose name was given by the propertyFile value in the Configuration identified to main by its command line arguments.