Package org.apache.hadoop.ipc

Class WeightedTimeCostProvider

java.lang.Object

org.apache.hadoop.ipc.WeightedTimeCostProvider

All Implemented Interfaces:

CostProvider

public class WeightedTimeCostProvider
extends Object
implements CostProvider

A CostProvider that calculates the cost for an operation as a weighted sum of its processing time values (see ProcessingDetails). This can be used by specifying the CommonConfigurationKeys.IPC_COST_PROVIDER_KEY configuration key.

This allows for configuration of how heavily each of the operations within ProcessingDetails is weighted. By default, ProcessingDetails.Timing.LOCKFREE, ProcessingDetails.Timing.RESPONSE, and ProcessingDetails.Timing.HANDLER times have a weight of 1, ProcessingDetails.Timing.LOCKSHARED has a weight of 10, ProcessingDetails.Timing.LOCKEXCLUSIVE has a weight of 100, and others are ignored. These values can all be configured using the WEIGHT_CONFIG_PREFIX key, prefixed with the IPC namespace, and suffixed with the name of the timing measurement from ProcessingDetails (all lowercase). For example, to set the lock exclusive weight to be 1000, set:

   ipc.8020.cost-provider.impl=org.apache.hadoop.ipc.WeightedTimeCostProvider
   ipc.8020.weighted-cost.lockexclusive=1000
 

Field Summary

Fields

Modifier and Type	Field	Description
static final String	WEIGHT_CONFIG_PREFIX	The prefix used in configuration values specifying the weight to use when determining the cost of an operation.

Constructor Summary

Constructors

Constructor	Description
WeightedTimeCostProvider()

Method Summary

Modifier and Type	Method	Description
long	getCost(ProcessingDetails details)	Calculates a weighted sum of the times stored on the provided processing details to be used as the cost in DecayRpcScheduler.
void	init(String namespace, Configuration conf)	Initialize this provider using the given configuration, examining only ones which fall within the provided namespace.

Methods inherited from class java.lang.Object

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

Field Details

WEIGHT_CONFIG_PREFIX

public static final String WEIGHT_CONFIG_PREFIX

The prefix used in configuration values specifying the weight to use when determining the cost of an operation. See the class Javadoc for more info.

See Also:

• Constant Field Values

Constructor Details

WeightedTimeCostProvider

public WeightedTimeCostProvider()

Method Details

init

public void init(String namespace,
 Configuration conf)

Description copied from interface: CostProvider

Initialize this provider using the given configuration, examining only ones which fall within the provided namespace.

Specified by:

init in interface CostProvider

Parameters:

namespace - The namespace to use when looking up configurations.

conf - The configuration

getCost

public long getCost(ProcessingDetails details)

Calculates a weighted sum of the times stored on the provided processing details to be used as the cost in DecayRpcScheduler.

Specified by:

getCost in interface CostProvider

Parameters:

details - Processing details

Returns:

The weighted sum of the times. The returned unit is the same as the default unit used by the provided processing details.