Jstorm源码分析--kill、rebanlance、activate、deactivate方法流程

这几个kill、rebanlance、activate、deactivate方法放在一起分析，是因为他们都依赖于nimbus定义的通用的 状态转移方法：

transitionName

********************************************这里只具体分析kill方法*********************************

一：初始化LocalCluster同拓扑提交一样，详见大神http://www.maoxiangyi.cn/index.php/archives/734；

二：LocalCluster完成构造之后，即可使用killTopology/ killTopologyWithOpts杀死拓扑。

方法的实现都会调用nimbus的对应方法。追踪nimbus的实现类，就能看到killTopology/ killTopologyWithOpts这两个方法，真正的实现类就是killTopologyWithOpts

@Override
	public void killTopology(String name) throws NotAliveException, TException {
		killTopologyWithOpts(name, new KillOptions());

	}

跟踪killTopologyWithOpts方法，方法定义如下：

public void killTopologyWithOpts(String topologyName, KillOptions options)

可以看到需要两个参数，分别是拓扑的名称和kill的操作。

@Override
	public void killTopologyWithOpts(String topologyName, KillOptions options)
			throws NotAliveException, TException {
		try {

			checkTopologyActive(data, topologyName, true);
			Integer wait_amt = null;
            //查看是否设置了杀死拓扑的等待时间，如果设置了就等待
			if (options.is_set_wait_secs()) {
				wait_amt = options.get_wait_secs();
			}
            //
			NimbusUtils.transitionName(data, topologyName, true,
					StatusType.kill, wait_amt);
		} catch (NotAliveException e) {
			String errMsg = "KillTopology Error, no this topology "
					+ topologyName;
			LOG.error(errMsg, e);
			throw new NotAliveException(errMsg);
		} catch (Exception e) {
			String errMsg = "Failed to kill topology " + topologyName;
			LOG.error(errMsg, e);
			throw new TException(errMsg);
		}

	}

流程：1，先查看拓扑是否Active,

public void checkTopologyActive(NimbusData nimbus, String topologyName,
			boolean bActive) throws Exception {
		if (isTopologyActive(nimbus.getStormClusterState(), topologyName) != bActive) {
			if (bActive) {
				throw new NotAliveException(topologyName + " is not alive");
			} else {
				throw new AlreadyAliveException(topologyName
						+ " is already active");
			}
		}
	}

跟下去

public boolean isTopologyActive(StormClusterState stormClusterState,
			String topologyName) throws Exception {
		boolean rtn = false;
		if (Cluster.get_topology_id(stormClusterState, topologyName) != null) {
			rtn = true;
		}
		return rtn;
	}

2：查看是否设置了kill操作是否设置了等待时间，如果设置了就等待后再执行

3：transitionName:这是在nimbus定义的通用的 状态转移方法，，他们会根据传入的转移事件做相应的处理。

public static <T> void transitionName(NimbusData data, String topologyName,
			boolean errorOnNoTransition, StatusType transition_status,
			T... args) throws Exception {
        //获得nimbus的信息，通过getStormClusterState查找对应的storm-id（实际上就是将storm-name 转换为storm-id的状态）,如果找到了，就调用transition方法。
		StormClusterState stormClusterState = data.getStormClusterState();
		String topologyId = Cluster.get_topology_id(stormClusterState,
				topologyName);
		if (topologyId == null) {
			throw new NotAliveException(topologyName);
		}
        //开始执行kill操作，转变拓扑状态。

		transition(data, topologyId, errorOnNoTransition, transition_status,
				args);
	}

</pre><p><span style="white-space:pre"></span></p><pre name="code" class="java">public static <T> void transitionName(NimbusData data, String topologyName,
			boolean errorOnNoTransition, StatusType transition_status,
			T... args) throws Exception {
        //通过nimbus的信息，获得storm客户端的状态。
		StormClusterState stormClusterState = data.getStormClusterState();
        //通过cluster的状态和拓扑的名称获得拓扑的ID。
		String topologyId = Cluster.get_topology_id(stormClusterState,
				topologyName);
		if (topologyId == null) {
			throw new NotAliveException(topologyName);
		}
        //开始执行kill操作，转变拓扑状态
		transition(data, topologyId, errorOnNoTransition, transition_status,
				args);
	}

4:transition：这是在nimbus定义的通用的 状态转移方法

transition方法会根据传入的转移事件，获取与当前Topology状态对应的状态转移函数，并且执行该函数取得转换后的新状态。

public static <T> void transition(NimbusData data, String topologyid,
			boolean errorOnNoTransition, StatusType transition_status,
			T... args) {
		try {
            //转变拓扑的状态
			data.getStatusTransition().transition(topologyid,
					errorOnNoTransition, transition_status, args);
		} catch (Exception e) {
			// TODO Auto-generated catch block
			LOG.error("Failed to do status transition,", e);
		}
	}

*********

最后一步追踪trantion有一步topologyLocks还没看太明白%>_<%

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