hadoop Capacity Scheduler计算能力调度器配置

计算能力调度器介绍

Capacity Scheduler支持以下特性：

(1) 计算能力保证。支持多个队列，某个作业可被提交到某一个队列中。每个队列会配置一定比例的计算资源，且所有提交到队列中的作业共享该队列中的资源。

(2) 灵活性。空闲资源会被分配给那些未达到资源使用上限的队列，当某个未达到资源的队列需要资源时，一旦出现空闲资源资源，便会分配给他们。

(3) 支持优先级。队列支持作业优先级调度（默认是FIFO）

(4) 多重租赁。综合考虑多种约束防止单个作业、用户或者队列独占队列或者集群中的资源。

(5) 基于资源的调度。 支持资源密集型作业，允许作业使用的资源量高于默认值，进而可容纳不同资源需求的作业。不过，当前仅支持内存资源的调度。

配置方法为

1. 复制$HADOOP_HOME/contrib/capacity-scheduler/hadoop-capacity-scheduler.jar  到$HADOOP_HOME/lib目录中

2. 修改namenode节点中的conf/mapred-site.xml文件

  <property>    <name>mapred.jobtracker.taskScheduler</name>    <value>org.apache.hadoop.mapred.CapacityTaskScheduler</value>  </property>  <property>    <name>mapred.queue.names</name>    <value>default,hadoop,hive</value>  </property>

3. 修改conf/capacity-scheduler.xml 配置文件

<?xml version="1.0"?><!-- This is the configuration file for the resource manager in Hadoop. --><!-- You can configure various scheduling parameters related to queues. --><!-- The properties for a queue follow a naming convention,such as, --><!-- mapred.capacity-scheduler.queue.<queue-name>.property-name. --><configuration>  <!-- Capacity scheduler Job Initialization configuration parameters -->  <property>    <name>mapred.capacity-scheduler.init-poll-interval</name>    <value>5000</value>    <description>The amount of time in miliseconds which is used to poll the job queues for jobs to initialize.    </description>  </property>  <property>    <name>mapred.capacity-scheduler.init-worker-threads</name>    <value>5</value>    <description>Number of worker threads which would be used by    Initialization poller to initialize jobs in a set of queue.    If number mentioned in property is equal to number of job queues    then a single thread would initialize jobs in a queue. If lesser    then a thread would get a set of queues assigned. If the number    is greater then number of threads would be equal to number of     job queues.    </description>  </property>  <property>      <name>mapred.capacity-scheduler.maximum-system-jobs</name>      <value>30</value>      <description>Maximum number of jobs in the system which can be initialized, concurrently, by the Capacity Scheduler.      </description>   </property> <!--hadoop queue-->  <property>    <name>mapred.capacity-scheduler.queue.hadoop.capacity</name>    <value>30</value>    <description>Percentage of the number of slots in the cluster that are to be available for jobs in this queue.    </description>      </property>    <property>    <name>mapred.capacity-scheduler.queue.hadoop.maximum-capacity</name>    <value>-1</value>    <description>    </description>      </property>    <property>    <name>mapred.capacity-scheduler.queue.hadoop.supports-priority</name>    <value>true</value>    <description></description>  </property>      <property>    <name>mapred.capacity-scheduler.queue.hadoop.minimum-user-limit-percent</name>    <value>100</value>    <description> </description>  </property>  <property>    <name>mapred.capacity-scheduler.queue.hadoop.user-limit-factor</name>    <value>3</value>    <description></description>  </property>  <property>    <name>mapred.capacity-scheduler.queue.hadoop.maximum-initialized-active-tasks</name>    <value>200000</value>    <description></description>  </property>  <property>    <name>mapred.capacity-scheduler.queue.hadoop.maximum-initialized-active-tasks-per-user</name>    <value>100000</value>    <description></description>  </property>    <property>    <name>mapred.capacity-scheduler.queue.hadoop.init-accept-jobs-factor</name>    <value>10</value>    <description></description>  </property>  <property>    <name>mapred.capacity-scheduler.default-maximum-initialized-jobs-per-user</name>    <value>5</value>    <description>The maximum number of jobs to be pre-initialized for a user    of the job queue.    </description>  </property>  <!-- hive --><property>    <name>mapred.capacity-scheduler.queue.hive.capacity</name>    <value>30</value>    <description></description>      </property>    <property>    <name>mapred.capacity-scheduler.queue.hive.maximum-capacity</name>    <value>-1</value>    <description></description>      </property>    <property>    <name>mapred.capacity-scheduler.queue.hive.supports-priority</name>    <value>true</value>    <description>If true, priorities of jobs will be taken into account in scheduling decisions.    </description>  </property>      <property>    <name>mapred.capacity-scheduler.queue.hive.minimum-user-limit-percent</name>    <value>100</value>    <description></description>  </property>  <property>    <name>mapred.capacity-scheduler.queue.hive.user-limit-factor</name>    <value>4</value>    <description>The multiple of the queue capacity which can be configured to allow a single user to acquire more slots.    </description>  </property>  <property>    <name>mapred.capacity-scheduler.queue.hive.maximum-initialized-active-tasks</name>    <value>200000</value>    <description></description>  </property>  <property>    <name>mapred.capacity-scheduler.queue.hive.maximum-initialized-active-tasks-per-user</name>    <value>100000</value>    <description></description>  </property>    <property>    <name>mapred.capacity-scheduler.queue.hive.init-accept-jobs-factor</name>    <value>10</value>    <description></description>  </property><!-- default -->   <property>    <name>mapred.capacity-scheduler.queue.default.capacity</name>    <value>40</value>    <description></description>      </property>    <property>    <name>mapred.capacity-scheduler.queue.default.maximum-capacity</name>    <value>-1</value>    <description></description>      </property>    <property>    <name>mapred.capacity-scheduler.queue.default.supports-priority</name>    <value>true</value>    <description></description>  </property>  <property>    <name>mapred.capacity-scheduler.queue.default.minimum-user-limit-percent</name>    <value>100</value>    <description></description>  </property>    <property>    <name>mapred.capacity-scheduler.queue.default.user-limit-factor</name>    <value>4</value>    <description></description>  </property>  <property>    <name>mapred.capacity-scheduler.queue.default.maximum-initialized-active-tasks</name>    <value>200000</value>    <description></description>  </property>  <property>    <name>mapred.capacity-scheduler.queue.default.maximum-initialized-active-tasks-per-user</name>    <value>100000</value>    <description></description>  </property>  <property>    <name>mapred.capacity-scheduler.queue.default.init-accept-jobs-factor</name>    <value>10</value>    <description></description>  </property></configuration>

保存文件后，重启jobtracker  

以后修改capacity-scheduler.xml文件后只需要执行命令hadoop mradmin -refreshQueues 就可以重新加载配置项。

4. 最后，如何使用该队列呢:
mapreduce:在Job的代码中，设置Job属于的队列,例如hive：
conf.setQueueName("hive");
hive:在执行hive任务时，设置hive属于的队列,例如hive:
set mapred.job.queue.name=hive;

设置队列的任务名称set mapred.job.name=hadooptest;

设置队列的优先级别set mapred.job.priority=HIGH;