Package org.apache.storm.redis.bolt
Class AbstractRedisBolt
java.lang.Object
org.apache.storm.topology.base.BaseComponent
org.apache.storm.topology.base.BaseRichBolt
org.apache.storm.topology.base.BaseTickTupleAwareRichBolt
org.apache.storm.redis.bolt.AbstractRedisBolt
- All Implemented Interfaces:
Serializable
,IBolt
,IComponent
,IRichBolt
- Direct Known Subclasses:
RedisFilterBolt
,RedisLookupBolt
,RedisStoreBolt
AbstractRedisBolt class is for users to implement custom bolts which makes interaction with Redis.
Due to environment abstraction, AbstractRedisBolt provides JedisCommands which contains only single key operations.
Custom Bolts may want to follow this pattern:
JedisCommands jedisCommands = null; try { jedisCommand = getInstance(); // do some works } finally { if (jedisCommand != null) { returnInstance(jedisCommand); } }
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Field Summary
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Constructor Summary
ConstructorDescriptionAbstractRedisBolt
(JedisClusterConfig config) Constructor for Redis Cluster environment (JedisCluster).AbstractRedisBolt
(JedisPoolConfig config) Constructor for single Redis environment (JedisPool). -
Method Summary
Modifier and TypeMethodDescriptionvoid
cleanup()
Called when an IBolt is going to be shutdown.protected JedisCommandsContainer
Borrow JedisCommands instance from container.void
prepare
(Map<String, Object> map, TopologyContext topologyContext, OutputCollector collector) Called when a task for this component is initialized within a worker on the cluster.Methods inherited from class org.apache.storm.topology.base.BaseTickTupleAwareRichBolt
execute, onTickTuple, process
Methods inherited from class org.apache.storm.topology.base.BaseComponent
getComponentConfiguration
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
Methods inherited from interface org.apache.storm.topology.IComponent
declareOutputFields, getComponentConfiguration
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Field Details
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collector
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Constructor Details
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AbstractRedisBolt
Constructor for single Redis environment (JedisPool).- Parameters:
config
- configuration for initializing JedisPool
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AbstractRedisBolt
Constructor for Redis Cluster environment (JedisCluster).- Parameters:
config
- configuration for initializing JedisCluster
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Method Details
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prepare
public void prepare(Map<String, Object> map, TopologyContext topologyContext, OutputCollector collector) Called when a task for this component is initialized within a worker on the cluster. It provides the bolt with the environment in which the bolt executes.This includes the:
- Parameters:
map
- The Storm configuration for this bolt. This is the configuration provided to the topology merged in with cluster configuration on this machine.topologyContext
- This object can be used to get information about this task's place within the topology, including the task id and component id of this task, input and output information, etc.collector
- The collector is used to emit tuples from this bolt. Tuples can be emitted at any time, including the prepare and cleanup methods. The collector is thread-safe and should be saved as an instance variable of this bolt object.
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getInstance
Borrow JedisCommands instance from container. JedisCommands is an interface which contains single key operations.- Returns:
- implementation of JedisCommands
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cleanup
public void cleanup()Description copied from interface:IBolt
Called when an IBolt is going to be shutdown. Storm will make a best-effort attempt to call this if the worker shutdown is orderly. TheConfig.SUPERVISOR_WORKER_SHUTDOWN_SLEEP_SECS
setting controls how long orderly shutdown is allowed to take. There is no guarantee that cleanup will be called if shutdown is not orderly, or if the shutdown exceeds the time limit.The one context where cleanup is guaranteed to be called is when a topology is killed when running Storm in local mode.
- Specified by:
cleanup
in interfaceIBolt
- Overrides:
cleanup
in classBaseRichBolt
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