org.apache.hadoop.mapred
Class QueueManager
java.lang.Object
org.apache.hadoop.mapred.QueueManager
@InterfaceAudience.Private
public class QueueManager
- extends Object
Class that exposes information about queues maintained by the Hadoop
Map/Reduce framework.
The Map/Reduce framework can be configured with one or more queues,
depending on the scheduler it is configured with. While some
schedulers work only with one queue, some schedulers support multiple
queues. Some schedulers also support the notion of queues within
queues - a feature called hierarchical queues.
Queue names are unique, and used as a key to lookup queues. Hierarchical
queues are named by a 'fully qualified name' such as q1:q2:q3, where
q2 is a child queue of q1 and q3 is a child queue of q2.
Leaf level queues are queues that contain no queues within them. Jobs
can be submitted only to leaf level queues.
Queues can be configured with various properties. Some of these
properties are common to all schedulers, and those are handled by this
class. Schedulers might also associate several custom properties with
queues. These properties are parsed and maintained per queue by the
framework. If schedulers need more complicated structure to maintain
configuration per queue, they are free to not use the facilities
provided by the framework, but define their own mechanisms. In such cases,
it is likely that the name of the queue will be used to relate the
common properties of a queue with scheduler specific properties.
Information related to a queue, such as its name, properties, scheduling
information and children are exposed by this class via a serializable
class called JobQueueInfo
.
Queues are configured in the configuration file mapred-queues.xml.
To support backwards compatibility, queues can also be configured
in mapred-site.xml. However, when configured in the latter, there is
no support for hierarchical queues.
Constructor Summary |
QueueManager(org.apache.hadoop.conf.Configuration clusterConf)
Construct a new QueueManager using configuration specified in the passed
in Configuration object. |
Methods inherited from class java.lang.Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
QUEUE_CONF_FILE_NAME
public static final String QUEUE_CONF_FILE_NAME
- See Also:
- Constant Field Values
QueueManager
public QueueManager(org.apache.hadoop.conf.Configuration clusterConf)
- Construct a new QueueManager using configuration specified in the passed
in
Configuration
object.
This instance supports queue configuration specified in mapred-site.xml,
but without support for hierarchical queues. If no queue configuration
is found in mapred-site.xml, it will then look for site configuration
in mapred-queues.xml supporting hierarchical queues.
- Parameters:
clusterConf
- mapreduce cluster configuration
toFullPropertyName
public static final String toFullPropertyName(String queue,
String property)
Copyright © 2013 Apache Software Foundation. All Rights Reserved.