spark count统计元素个数

太简单了，直接上代码，不解析

public static void myCount(){

SparkConf conf=new SparkConf()
       .setMaster("local")
       .setAppName("myCount");
       JavaSparkContext sc=new JavaSparkContext(conf);
       List<Integer> list=Arrays.asList(1,2,3,4,4);
       JavaRDD<Integer> listRdd=sc.parallelize(list, 2);
       long counts=listRdd.count();
       System.out.println("count:"+counts);
       sc.close();

}

结果：

count:5

我始终觉得打印出来的日志很重要：

Using Spark's default log4j profile: org/apache/spark/log4j-defaults.properties
16/05/03 22:54:42 INFO SparkContext: Running Spark version 1.6.1
16/05/03 22:55:02 WARN NativeCodeLoader: Unable to load native-hadoop library for your platform... using builtin-java classes where applicable
16/05/03 22:55:02 INFO SecurityManager: Changing view acls to: admin
16/05/03 22:55:02 INFO SecurityManager: Changing modify acls to: admin
16/05/03 22:55:02 INFO SecurityManager: SecurityManager: authentication disabled; ui acls disabled; users with view permissions: Set(admin); users with modify permissions: Set(admin)
16/05/03 22:55:04 INFO Utils: Successfully started service 'sparkDriver' on port 55095.
16/05/03 22:55:05 INFO Slf4jLogger: Slf4jLogger started
16/05/03 22:55:05 INFO Remoting: Starting remoting
16/05/03 22:55:05 INFO Remoting: Remoting started; listening on addresses :[akka.tcp://sparkDriverActorSystem@192.168.213.1:55108]
16/05/03 22:55:06 INFO Utils: Successfully started service 'sparkDriverActorSystem' on port 55108.
16/05/03 22:55:06 INFO SparkEnv: Registering MapOutputTracker
16/05/03 22:55:06 INFO SparkEnv: Registering BlockManagerMaster
16/05/03 22:55:06 INFO DiskBlockManager: Created local directory at C:\Users\admin\AppData\Local\Temp\blockmgr-3aaa5046-0d05-4c75-8734-02b0121f3a1e
16/05/03 22:55:06 INFO MemoryStore: MemoryStore started with capacity 2.4 GB
16/05/03 22:55:06 INFO SparkEnv: Registering OutputCommitCoordinator
16/05/03 22:55:07 INFO Utils: Successfully started service 'SparkUI' on port 4040.
16/05/03 22:55:07 INFO SparkUI: Started SparkUI at http://192.168.213.1:4040
16/05/03 22:55:07 INFO Executor: Starting executor ID driver on host localhost
16/05/03 22:55:07 INFO Utils: Successfully started service 'org.apache.spark.network.netty.NettyBlockTransferService' on port 55116.
16/05/03 22:55:07 INFO NettyBlockTransferService: Server created on 55116
16/05/03 22:55:07 INFO BlockManagerMaster: Trying to register BlockManager
16/05/03 22:55:07 INFO BlockManagerMasterEndpoint: Registering block manager localhost:55116 with 2.4 GB RAM, BlockManagerId(driver, localhost, 55116)
16/05/03 22:55:07 INFO BlockManagerMaster: Registered BlockManager
16/05/03 22:55:09 INFO SparkContext: Starting job: count at ActionOperation.java:84
16/05/03 22:55:09 INFO DAGScheduler: Got job 0 (count at ActionOperation.java:84) with 2 output partitions
16/05/03 22:55:09 INFO DAGScheduler: Final stage: ResultStage 0 (count at ActionOperation.java:84)
16/05/03 22:55:09 INFO DAGScheduler: Parents of final stage: List()
16/05/03 22:55:09 INFO DAGScheduler: Missing parents: List()
16/05/03 22:55:09 INFO DAGScheduler: Submitting ResultStage 0 (ParallelCollectionRDD[0] at parallelize at ActionOperation.java:83), which has no missing parents
16/05/03 22:55:10 INFO MemoryStore: Block broadcast_0 stored as values in memory (estimated size 1320.0 B, free 1320.0 B)
16/05/03 22:55:10 INFO MemoryStore: Block broadcast_0_piece0 stored as bytes in memory (estimated size 927.0 B, free 2.2 KB)
16/05/03 22:55:10 INFO BlockManagerInfo: Added broadcast_0_piece0 in memory on localhost:55116 (size: 927.0 B, free: 2.4 GB)
16/05/03 22:55:10 INFO SparkContext: Created broadcast 0 from broadcast at DAGScheduler.scala:1006
16/05/03 22:55:10 INFO DAGScheduler: Submitting 2 missing tasks from ResultStage 0 (ParallelCollectionRDD[0] at parallelize at ActionOperation.java:83)
16/05/03 22:55:10 INFO TaskSchedulerImpl: Adding task set 0.0 with 2 tasks
16/05/03 22:55:10 INFO TaskSetManager: Starting task 0.0 in stage 0.0 (TID 0, localhost, partition 0,PROCESS_LOCAL, 2140 bytes)
16/05/03 22:55:10 INFO Executor: Running task 0.0 in stage 0.0 (TID 0)
16/05/03 22:55:10 INFO Executor: Finished task 0.0 in stage 0.0 (TID 0). 953 bytes result sent to driver
16/05/03 22:55:10 INFO TaskSetManager: Starting task 1.0 in stage 0.0 (TID 1, localhost, partition 1,PROCESS_LOCAL, 2145 bytes)
16/05/03 22:55:10 INFO Executor: Running task 1.0 in stage 0.0 (TID 1)
16/05/03 22:55:10 INFO TaskSetManager: Finished task 0.0 in stage 0.0 (TID 0) in 257 ms on localhost (1/2)
16/05/03 22:55:10 INFO Executor: Finished task 1.0 in stage 0.0 (TID 1). 953 bytes result sent to driver
16/05/03 22:55:10 INFO TaskSetManager: Finished task 1.0 in stage 0.0 (TID 1) in 55 ms on localhost (2/2)
16/05/03 22:55:10 INFO DAGScheduler: ResultStage 0 (count at ActionOperation.java:84) finished in 0.352 s
16/05/03 22:55:10 INFO TaskSchedulerImpl: Removed TaskSet 0.0, whose tasks have all completed, from pool
16/05/03 22:55:10 INFO DAGScheduler: Job 0 finished: count at ActionOperation.java:84, took 1.136850 s
count:5
16/05/03 22:55:10 INFO SparkUI: Stopped Spark web UI at http://192.168.213.1:4040
16/05/03 22:55:10 INFO MapOutputTrackerMasterEndpoint: MapOutputTrackerMasterEndpoint stopped!
16/05/03 22:55:10 INFO MemoryStore: MemoryStore cleared
16/05/03 22:55:10 INFO BlockManager: BlockManager stopped
16/05/03 22:55:10 INFO BlockManagerMaster: BlockManagerMaster stopped
16/05/03 22:55:10 INFO OutputCommitCoordinator$OutputCommitCoordinatorEndpoint: OutputCommitCoordinator stopped!
16/05/03 22:55:10 INFO SparkContext: Successfully stopped SparkContext
16/05/03 22:55:10 INFO ShutdownHookManager: Shutdown hook called
16/05/03 22:55:10 INFO ShutdownHookManager: Deleting directory C:\Users\admin\AppData\Local\Temp\spark-221cf0db-fb4a-4577-8785-ac392b53425e
16/05/03 22:55:10 INFO RemoteActorRefProvider$RemotingTerminator: Shutting down remote daemon.

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