捣鼓了一下，先来个手动挡吧。自动挡要设置ssh无密码登陆啥的，后面开搞。
一、手动多台机链接master
手动链接master其实上篇已经用过。
这里有两台机器：
10.60.215.41 启动master、worker1、application(spark shell)
10.0.2.15 启动worker2
具体步骤如下：
1.在10.60.215.41 上
$SPARK_HOME $ ./sbin/start-master.sh
$SPARK_HOME $./bin/spark-class org.apache.spark.deploy.worker.Worker spark://qpzhangdeMac-mini.local:7077
2.在10.0.2.15上
$SPARK_HOME $./bin/spark-class org.apache.spark.deploy.worker.Worker spark://qpzhangdeMac-mini.local:7077
这里需要注意的是，貌似spark用了akka的库，spark的master URL里面必须要用hostname(尝试从配置文件里面改成IP,也没生效)，否则会报错：
15/03/20 17:14:05 ERROR EndpointWriter: dropping message [class akka.actor.ActorSelectionMessage] for non-local recipient [Actor[akka.tcp://sparkMaster@10.60.215.41:7077/]] arriving at [akka.tcp://sparkMaster@10.60.215.41:7077] inbound addresses are [akka.tcp://sparkMaster@qpzhangdeMac-mini.local:7077]
要在10.0.2.15机器的hosts里面，设置qpzhangdeMac-mini.local对应的IP为master 10.60.215.41,否则无法转换成IP进行链接。
开始以为把master kill之后，master会自动转为worker1 或者 work2中的一个，但是并没有。worker只是不断尝试重连。
15/03/20 17:41:05 INFO Worker: Retrying connection to master (attempt # 2) 15/03/20 17:41:05 WARN EndpointWriter: AssociationError [akka.tcp://sparkWorker@10.60.215.41:53899] -> [akka.tcp://sparkMaster@qpzhangdeMac-mini.local:7077]: Error [Invalid address: akka.tcp://sparkMaster@qpzhangdeMac-mini.local:7077] [ akka.remote.InvalidAssociation: Invalid address: akka.tcp://sparkMaster@qpzhangdeMac-mini.local:7077 Caused by: akka.remote.transport.Transport$InvalidAssociationException: Connection refused: qpzhangdeMac-mini.local/10.60.215.41:7077
重新启动master之后, 重连成功。
15/03/20 18:27:41 INFO Worker: Retrying connection to master (attempt # 10) 15/03/20 18:27:41 INFO Worker: Successfully registered with master spark://qpzhangdeMac-mini.local:7077
这里暂且留下几个疑问：
1）原来salve只是workers 么？worker是不会升级为master的,这里没有选举之说。
2）master挂了之后，重启，任务会丢失么？
3）单个worker是否可以注册到多个master上？
3.在10.60.215.41 上
启动spark shell，下达任务。
scala> val textFile = sc.textFile("/var/spark/README.md") 15/03/20 17:55:41 INFO MemoryStore: ensureFreeSpace(73391) called with curMem=186365, maxMem=555755765 15/03/20 17:55:41 INFO MemoryStore: Block broadcast_2 stored as values in memory (estimated size 71.7 KB, free 529.8 MB) 15/03/20 17:55:41 INFO MemoryStore: ensureFreeSpace(31262) called with curMem=259756, maxMem=555755765 15/03/20 17:55:41 INFO MemoryStore: Block broadcast_2_piece0 stored as bytes in memory (estimated size 30.5 KB, free 529.7 MB) 15/03/20 17:55:41 INFO BlockManagerInfo: Added broadcast_2_piece0 in memory on 10.60.215.41:53983 (size: 30.5 KB, free: 530.0 MB) 15/03/20 17:55:41 INFO BlockManagerMaster: Updated info of block broadcast_2_piece0 15/03/20 17:55:41 INFO SparkContext: Created broadcast 2 from textFile at <console>:21 textFile: org.apache.spark.rdd.RDD[String] = /var/spark/README.md MapPartitionsRDD[3] at textFile at <console>:21 scala> textFile.count() 15/03/20 17:55:45 INFO FileInputFormat: Total input paths to process : 1 15/03/20 17:55:45 INFO SparkContext: Starting job: count at <console>:24 15/03/20 17:55:45 INFO DAGScheduler: Got job 1 (count at <console>:24) with 2 output partitions (allowLocal=false) 15/03/20 17:55:45 INFO DAGScheduler: Final stage: Stage 1(count at <console>:24) 15/03/20 17:55:45 INFO DAGScheduler: Parents of final stage: List() 15/03/20 17:55:45 INFO DAGScheduler: Missing parents: List() 15/03/20 17:55:45 INFO DAGScheduler: Submitting Stage 1 (/var/spark/README.md MapPartitionsRDD[3] at textFile at <console>:21), which has no missing parents 15/03/20 17:55:45 INFO MemoryStore: ensureFreeSpace(2640) called with curMem=291018, maxMem=555755765 15/03/20 17:55:45 INFO MemoryStore: Block broadcast_3 stored as values in memory (estimated size 2.6 KB, free 529.7 MB) 15/03/20 17:55:45 INFO MemoryStore: ensureFreeSpace(1931) called with curMem=293658, maxMem=555755765 15/03/20 17:55:45 INFO MemoryStore: Block broadcast_3_piece0 stored as bytes in memory (estimated size 1931.0 B, free 529.7 MB) 15/03/20 17:55:45 INFO BlockManagerInfo: Added broadcast_3_piece0 in memory on 10.60.215.41:53983 (size: 1931.0 B, free: 530.0 MB) 15/03/20 17:55:45 INFO BlockManagerMaster: Updated info of block broadcast_3_piece0 15/03/20 17:55:45 INFO SparkContext: Created broadcast 3 from broadcast at DAGScheduler.scala:839 15/03/20 17:55:45 INFO DAGScheduler: Submitting 2 missing tasks from Stage 1 (/var/spark/README.md MapPartitionsRDD[3] at textFile at <console>:21) 15/03/20 17:55:45 INFO TaskSchedulerImpl: Adding task set 1.0 with 2 tasks 15/03/20 17:55:45 INFO TaskSetManager: Starting task 0.0 in stage 1.0 (TID 3, 10.60.215.41, PROCESS_LOCAL, 1289 bytes) 15/03/20 17:55:45 INFO TaskSetManager: Starting task 1.0 in stage 1.0 (TID 4, 10.0.2.15, PROCESS_LOCAL, 1289 bytes) 15/03/20 17:55:45 INFO BlockManagerInfo: Added broadcast_3_piece0 in memory on 10.60.215.41:53990 (size: 1931.0 B, free: 265.1 MB) 15/03/20 17:55:45 INFO BlockManagerInfo: Added broadcast_2_piece0 in memory on 10.60.215.41:53990 (size: 30.5 KB, free: 265.1 MB) 15/03/20 17:55:45 INFO BlockManagerInfo: Added broadcast_3_piece0 in memory on 10.0.2.15:53284 (size: 1931.0 B, free: 267.2 MB) 15/03/20 17:55:45 INFO BlockManagerInfo: Added broadcast_2_piece0 in memory on 10.0.2.15:53284 (size: 30.5 KB, free: 267.2 MB) 15/03/20 17:55:45 INFO TaskSetManager: Finished task 0.0 in stage 1.0 (TID 3) in 127 ms on 10.60.215.41 (1/2) 15/03/20 17:55:46 INFO TaskSetManager: Finished task 1.0 in stage 1.0 (TID 4) in 470 ms on 10.0.2.15 (2/2) 15/03/20 17:55:46 INFO DAGScheduler: Stage 1 (count at <console>:24) finished in 0.471 s 15/03/20 17:55:46 INFO TaskSchedulerImpl: Removed TaskSet 1.0, whose tasks have all completed, from pool 15/03/20 17:55:46 INFO DAGScheduler: Job 1 finished: count at <console>:24, took 0.487544 s res2: Long = 98 scala> val linesWithSpark = textFile.filter(line => line.contains("Spark")) linesWithSpark: org.apache.spark.rdd.RDD[String] = MapPartitionsRDD[4] at filter at <console>:23 scala> linesWithSpark.count() 15/03/20 17:56:53 INFO SparkContext: Starting job: count at <console>:26 15/03/20 17:56:53 INFO DAGScheduler: Got job 2 (count at <console>:26) with 2 output partitions (allowLocal=false) 15/03/20 17:56:53 INFO DAGScheduler: Final stage: Stage 2(count at <console>:26) 15/03/20 17:56:53 INFO DAGScheduler: Parents of final stage: List() 15/03/20 17:56:53 INFO DAGScheduler: Missing parents: List() 15/03/20 17:56:53 INFO DAGScheduler: Submitting Stage 2 (MapPartitionsRDD[4] at filter at <console>:23), which has no missing parents 15/03/20 17:56:53 INFO MemoryStore: ensureFreeSpace(2848) called with curMem=295589, maxMem=555755765 15/03/20 17:56:53 INFO MemoryStore: Block broadcast_4 stored as values in memory (estimated size 2.8 KB, free 529.7 MB) 15/03/20 17:56:53 INFO MemoryStore: ensureFreeSpace(2034) called with curMem=298437, maxMem=555755765 15/03/20 17:56:53 INFO MemoryStore: Block broadcast_4_piece0 stored as bytes in memory (estimated size 2034.0 B, free 529.7 MB) 15/03/20 17:56:53 INFO BlockManagerInfo: Added broadcast_4_piece0 in memory on 10.60.215.41:53983 (size: 2034.0 B, free: 530.0 MB) 15/03/20 17:56:53 INFO BlockManagerMaster: Updated info of block broadcast_4_piece0 15/03/20 17:56:53 INFO SparkContext: Created broadcast 4 from broadcast at DAGScheduler.scala:839 15/03/20 17:56:53 INFO DAGScheduler: Submitting 2 missing tasks from Stage 2 (MapPartitionsRDD[4] at filter at <console>:23) 15/03/20 17:56:53 INFO TaskSchedulerImpl: Adding task set 2.0 with 2 tasks 15/03/20 17:56:53 INFO TaskSetManager: Starting task 0.0 in stage 2.0 (TID 5, 10.0.2.15, PROCESS_LOCAL, 1289 bytes) 15/03/20 17:56:53 INFO TaskSetManager: Starting task 1.0 in stage 2.0 (TID 6, 10.60.215.41, PROCESS_LOCAL, 1289 bytes) 15/03/20 17:56:53 INFO BlockManagerInfo: Added broadcast_4_piece0 in memory on 10.60.215.41:53990 (size: 2034.0 B, free: 265.1 MB) 15/03/20 17:56:53 INFO BlockManagerInfo: Added broadcast_4_piece0 in memory on 10.0.2.15:53284 (size: 2034.0 B, free: 267.2 MB) 15/03/20 17:56:53 INFO TaskSetManager: Finished task 1.0 in stage 2.0 (TID 6) in 113 ms on 10.60.215.41 (1/2) 15/03/20 17:56:53 INFO TaskSetManager: Finished task 0.0 in stage 2.0 (TID 5) in 122 ms on 10.0.2.15 (2/2) 15/03/20 17:56:53 INFO DAGScheduler: Stage 2 (count at <console>:26) finished in 0.122 s 15/03/20 17:56:53 INFO TaskSchedulerImpl: Removed TaskSet 2.0, whose tasks have all completed, from pool 15/03/20 17:56:53 INFO DAGScheduler: Job 2 finished: count at <console>:26, took 0.137589 s res3: Long = 19
从日志里面看到，任务都是分解成2个，分别发送到2个worker上面执行。
这里不免想到以下问题：
1）master的任务是怎么分配的？local file 是传递path到不同的worker上去，还是把内容读取了传递过去？
2）如果仅仅是传递path过去，那么每个work都要读一遍文件？全部读取，还是移位读取的呢？
多执行几次，然后看worker的日志，发现是传path，加上文件分片的；不同的分片应该是随机分到对应的worker的，因为几次命令，每个worker收到的分片地址不一样。
这里还有一个问题，如果是从HDFS上面读取文件，一个地址是可以被不同机器的worker读取到的。如果是读本地local path的话，那么就呵呵了，你要自己把文件内容分派到不同的worker机器上去了。
可在 http://10.60.215.41:4040/executors/ 上面可以看到当前执行task的 workers list，以及task被执行的状态。
二，自动挡部署
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其实原理也很简单，就是shell脚本，根据配置的slavers机器，通过ssh登录到slaver机器上面，切换到对应的目录，启动slave。
相比手动启动slaver，这个一键启动只需要在一台master机器上完成。
前提是，你必须配置好ssh的无密码登录，你可以参考这里。
配置好后，修改conf目录下的slavers列表：
root@qp-zhang:/var/spark# cat conf/slaves
# A Spark Worker will be started on each of the machines listed below.
localhost
root@qpzhangdeMac-mini.local
采用对应的slavers脚本启动即可：
root@qp-zhang:/var/spark# ./sbin/start-slaves.sh root@qpzhangdeMac-mini.local: starting org.apache.spark.deploy.worker.Worker, logging to /private/var/spark/sbin/../logs/spark-root-org.apache.spark.deploy.worker.Worker-1-qpzhangdeMac-mini.local.out localhost: starting org.apache.spark.deploy.worker.Worker, logging to /var/spark/sbin/../logs/spark-root-org.apache.spark.deploy.worker.Worker-1-qp-zhang.out
这时，可以通过
http://localhost:8080/ 查看当前master的slavers（也可以说是workers）。
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