Package com.yahoo.vespa.http.client.core.operationProcessor

Class IncompleteResultsThrottler

java.lang.Object

com.yahoo.vespa.http.client.core.operationProcessor.IncompleteResultsThrottler

public class IncompleteResultsThrottler
extends Object

Adjusts in-flight operations based on throughput. It will walk the graph and try to find local optimum. It looks at the throughput, adjust max in-flight based on the previous throughput and settings. In the beginning it moves faster, and then stabilizes. It will wait a bit after adjusting before it starts to sample, since there is a latency between adjustment and result. There are several mechanisms to reduce impact of several clients running in parallel. The window size has a random part, and the wait time before sampling after adjustment has a random part as well. To avoid running wild with large values of max-in flight, it is tuned to stay on the smaller part, and rather reduce max-in flight than to have a too large value. In case the where the queue is moved to minimum size, it will now and then increase queue size to get more sample data and possibly grow size. Class is fully thread safe, i.e. all public methods are thread safe.

Author:

dybis

Field Summary

Fields

Modifier and Type	Field	Description
protected static int	INITIAL_MAX_IN_FLIGHT_VALUE
final long	phaseSizeMs
protected static int	SECOND_MAX_IN_FLIGHT_VALUE

Constructor Summary

Constructors

Constructor	Description
IncompleteResultsThrottler(int minInFlightValue, int maxInFlightValue, Clock clock, ThrottlePolicy policy)	Creates the throttler.

Method Summary

Modifier and Type	Method	Description
int	availableCapacity()
String	getDebugMessage()
void	operationStart()
void	resultReady(boolean success)
protected int	waitingThreads()

Methods inherited from class java.lang.Object

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

Field Details

phaseSizeMs

public final long phaseSizeMs

INITIAL_MAX_IN_FLIGHT_VALUE

protected static int INITIAL_MAX_IN_FLIGHT_VALUE

SECOND_MAX_IN_FLIGHT_VALUE

protected static int SECOND_MAX_IN_FLIGHT_VALUE

Constructor Details

IncompleteResultsThrottler

public IncompleteResultsThrottler(int minInFlightValue,
 int maxInFlightValue,
 Clock clock,
 ThrottlePolicy policy)

Creates the throttler.

Parameters:

minInFlightValue - the throttler will never throttle beyond this limit.

maxInFlightValue - the throttler will never throttle above this limit. If zero, no limit.

clock - use to calculate window size. Can be null if minWindowSize and maxInFlightValue are equal.

policy - is the algorithm for finding next value of the number of in-flight documents operations.

Method Details

availableCapacity

public int availableCapacity()

operationStart

public void operationStart()

getDebugMessage

public String getDebugMessage()

resultReady

public void resultReady(boolean success)

waitingThreads

protected int waitingThreads()