docs/Hooks.md - storm - Git at Google

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 title: Hooks
 layout: documentation
 documentation: true
 ---
 Storm provides hooks with which you can insert custom code to run on any number of events within Storm. You create a hook by extending the [BaseTaskHook](javadocs/org/apache/storm/hooks/BaseTaskHook.html) class and overriding the appropriate method for the event you want to catch. There are two ways to register your hook:

 1. In the open method of your spout or prepare method of your bolt using the [TopologyContext](javadocs/org/apache/storm/task/TopologyContext.html#addTaskHook) method.
 2. Through the Storm configuration using the ["topology.auto.task.hooks"](javadocs/org/apache/storm/Config.html#TOPOLOGY_AUTO_TASK_HOOKS) config. These hooks are automatically registered in every spout or bolt, and are useful for doing things like integrating with a custom monitoring system.
	---
	title: Hooks
	layout: documentation
	documentation: true
	---
	Storm provides hooks with which you can insert custom code to run on any number of events within Storm. You create a hook by extending the [BaseTaskHook](javadocs/org/apache/storm/hooks/BaseTaskHook.html) class and overriding the appropriate method for the event you want to catch. There are two ways to register your hook:

	1. In the open method of your spout or prepare method of your bolt using the [TopologyContext](javadocs/org/apache/storm/task/TopologyContext.html#addTaskHook) method.
	2. Through the Storm configuration using the ["topology.auto.task.hooks"](javadocs/org/apache/storm/Config.html#TOPOLOGY_AUTO_TASK_HOOKS) config. These hooks are automatically registered in every spout or bolt, and are useful for doing things like integrating with a custom monitoring system.