org.apache.spark.storage

Class DefaultTopologyMapper

Object

org.apache.spark.storage.TopologyMapper

org.apache.spark.storage.DefaultTopologyMapper

public class DefaultTopologyMapper
extends TopologyMapper

A TopologyMapper that assumes all nodes are in the same rack

Constructor Summary

Constructors

Constructor and Description
DefaultTopologyMapper(SparkConf conf)

Method Summary

Methods

Modifier and Type	Method and Description
scala.Option<String>	getTopologyForHost(String hostname) Gets the topology information given the host name

Methods inherited from class Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

DefaultTopologyMapper

public DefaultTopologyMapper(SparkConf conf)

Method Detail

getTopologyForHost

public scala.Option<String> getTopologyForHost(String hostname)

Description copied from class: TopologyMapper

Gets the topology information given the host name

Specified by:

getTopologyForHost in class TopologyMapper

Parameters:

hostname - Hostname

Returns:

topology information for the given hostname. One can use a 'topology delimiter' to make this topology information nested. For example : ‘/myrack/myhost’, where ‘/’ is the topology delimiter, ‘myrack’ is the topology identifier, and ‘myhost’ is the individual host. This function only returns the topology information without the hostname. This information can be used when choosing executors for block replication to discern executors from a different rack than a candidate executor, for example.

An implementation can choose to use empty strings or None in case topology info is not available. This would imply that all such executors belong to the same rack.