DoRebalanceTransitionCallback.java

package org.act.tstream.callback.impl;

import org.act.tstream.callback.BaseCallback;
import org.apache.log4j.Logger;

import org.act.tstream.cluster.StormStatus;
import org.act.tstream.daemon.nimbus.NimbusData;
import org.act.tstream.daemon.nimbus.TopologyAssign;
import org.act.tstream.daemon.nimbus.TopologyAssignEvent;

/**
 * Do real rebalance action.
 * 
 * After nimbus receive one rebalance command, it will do as following: 1. set
 * topology status as rebalancing 2. delay 2 * timeout seconds 3. do this
 * callback
 * 
 * @author Xin.Li/Longda
 * 
 */
public class DoRebalanceTransitionCallback extends BaseCallback {

	private static Logger LOG = Logger
			.getLogger(DoRebalanceTransitionCallback.class);

	private String topologyid;
	private StormStatus oldStatus;

	public DoRebalanceTransitionCallback(NimbusData data, String topologyid,
			StormStatus status) {
		// this.data = data;
		this.topologyid = topologyid;
		this.oldStatus = status;
	}

	@Override
	public <T> Object execute(T... args) {
		try {
			TopologyAssignEvent event = new TopologyAssignEvent();

			event.setTopologyId(topologyid);
			event.setScratch(true);
			event.setOldStatus(oldStatus);

			TopologyAssign.push(event);

		} catch (Exception e) {
			LOG.error("do-rebalance error!", e);
		}
		// FIXME Why oldStatus?
		return oldStatus.getOldStatus();
	}

}