org.wikidata.query.rdf.blazegraph.throttling

Class ThrottlingState

java.lang.Object

org.wikidata.query.rdf.blazegraph.throttling.ThrottlingState

public final class ThrottlingState
extends Object

Keeps track of resource useage for a client. This class tracks of the request time consumed and of the errors.

Constructor Summary

Constructors

Constructor and Description
ThrottlingState(org.isomorphism.util.TokenBucket timeBucket, org.isomorphism.util.TokenBucket errorsBucket) Constructor.

Method Summary

Modifier and Type	Method and Description
void	consumeError() Consumes errors from the error bucket.
void	consumeTime(Duration elapsed) Consumes request time from the time bucket.
Duration	getBackoffDelay() How long should a client wait before sending the next request.
boolean	isThrottled() Should this client be throttled.

Methods inherited from class java.lang.Object

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

Constructor Detail

ThrottlingState

public ThrottlingState(org.isomorphism.util.TokenBucket timeBucket,
                       org.isomorphism.util.TokenBucket errorsBucket)

Constructor.

Parameters:

timeBucket - bucket to track requests time

errorsBucket - bucket to track errors

Method Detail

isThrottled

public boolean isThrottled()

Should this client be throttled.

getBackoffDelay

public Duration getBackoffDelay()

How long should a client wait before sending the next request.

Returns:

0 if the client is not throttled, or the backoff delay otherwise.

consumeTime

public void consumeTime(Duration elapsed)

Consumes request time from the time bucket. If the time bucket contains less tokens than what the request consumed, all available tokens will be consumed: min(elapsed.toMillis(), timeBucket.getNumTokens()).

Parameters:

elapsed - time elapsed during the request

consumeError

public void consumeError()

Consumes errors from the error bucket. If the error bucket is already empty, does nothing.