Hadoop Yarn:如何限制Spark的动态自分配资源

Question

在Yarn下运行的Hadoop集群中，我们遇到了一个问题，一些"聪明"的人能够通过在pySpark Jupyter笔记本中配置Spark作业来消耗大量资源，例如:

conf = (SparkConf()
        .setAppName("name")
        .setMaster("yarn-client")
        .set("spark.executor.instances", "1000")
        .set("spark.executor.memory", "64g")
        )
sc = SparkContext(conf=conf)

这就导致了这样一种情况:这些人实际上排挤了那些不那么"聪明"的人。

是否有一种方法可以禁止用户自分配资源并将资源分配单独留给Yarn?

Answer 1

YARN对多租户集群的队列容量规划有很好的支持，YARN ResourceManager默认使用CapacityScheduler。

这里我们将队列名称作为alpha在spark提交中用于演示。

$ ./bin/spark-submit --class path/to/class/file 
    --master yarn-cluster 
    --queue alpha 
    jar/location 
    args

设置队列:

CapacityScheduler有一个名为root的预定义队列。系统中的所有队列都是根队列的子队列。在capacity-scheduler.xml中，参数yarn.scheduler.capacity.root.queues用于定义子队列;

例如，要创建3个队列，则以逗号分隔的列表指定队列的名称。

<property>
    <name>yarn.scheduler.capacity.root.queues</name>
    <value>alpha,beta,default</value>
    <description>The queues at the this level (root is the root queue).</description>
</property>

这些是容量规划需要考虑的几个重要属性。

<property>
    <name>yarn.scheduler.capacity.root.alpha.capacity</name>
    <value>50</value>
    <description>Queue capacity in percentage (%) as a float (e.g. 12.5). The sum of capacities for all queues, at each level, must be equal to 100. Applications in the queue may consume more resources than the queue’s capacity if there are free resources, providing elasticity.</description>
</property>
<property>
    <name>yarn.scheduler.capacity.root.alpha.maximum-capacity</name>
    <value>80</value>
    <description>Maximum queue capacity in percentage (%) as a float. This limits the elasticity for applications in the queue. Defaults to -1 which disables it.</description>
</property>
<property>
    <name>yarn.scheduler.capacity.root.alpha.minimum-capacity</name>
    <value>10</value>
    <description>Each queue enforces a limit on the percentage of resources allocated to a user at any given time, if there is demand for resources. The user limit can vary between a minimum and maximum value. The former (the minimum value) is set to this property value and the latter (the maximum value) depends on the number of users who have submitted applications. For e.g., suppose the value of this property is 25. If two users have submitted applications to a queue, no single user can use more than 50% of the queue resources. If a third user submits an application, no single user can use more than 33% of the queue resources. With 4 or more users, no user can use more than 25% of the queues resources. A value of 100 implies no user limits are imposed. The default is 100. Value is specified as a integer.</description>
</property>

链接:YARN CapacityScheduler Queue Properties