一个storm程序的执行流程 [英] Execution flow of a storm program

问题描述

我是 Storm 的新手，试图了解从 spout 到 bolt 的不同方法的执行流程.就像 spout 有不同的方法，比如

I am new in storm and trying to understand the flow of execution of different methods from spout to bolt . Like spout has different methods like

nextTuple()

nextTuple()

打开()

declareOutputFields()

declareOutputFields()

激活()

停用()

和 bolt 有类似

and bolt has methods like

准备()

执行()

清理()

declareOutputFields()

declareOutputFields()

那么谁能告诉我这些方法的执行顺序?

so can anyone tell me the sequence of execution of these methods ?

推荐答案

首先，当您的拓扑启动时...

First, when your topology is started...

1. 创建喷口和螺栓
2. declareOutputFields
3. 喷口/螺栓序列化并分配给工人

其次，在集群上某处的每个工作线程中...

Second, in each worker somewhere on the cluster...

1. Spouts open 和 Bolts prepare(发生一次)
2. 在一个循环中...
   • Spouts 调用 ack、fail 和 nextTuple
   • 螺栓调用execute

1. Spouts open and Bolts prepare (happens once)
2. In a loop...
   • Spouts call ack, fail, and nextTuple
   • Bolts call execute

<小时>

如果您的拓扑已停用...

---

If your topology is deactivated...

• 您的 spouts deactivate 方法将被调用.当您再次激活拓扑时，将调用 activate.

• Your spouts deactivate method will be called. When you activate the topology again then activate will be called.

如果您的拓扑被终止...

If your topology is killed...

• Spouts 可能有 close 调用
• 螺栓可能调用了cleanup

• Spouts might have close called
• Bolts might have cleanup called

注意:

不保证 close 会被调用，因为主管 kill -9 在集群上的工作进程.来源

There is no guarentee that close will be called, because the supervisor kill -9's worker processes on the cluster. source

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