org.forgerock.http.filter.throttling

Class TokenBucketThrottlingStrategy

java.lang.Object

org.forgerock.http.filter.throttling.TokenBucketThrottlingStrategy

All Implemented Interfaces:

ThrottlingStrategy

public class TokenBucketThrottlingStrategy
extends Object
implements ThrottlingStrategy

The rate limiting is implemented as a token bucket strategy that gives us the ability to handle rate limits through a sliding window. Multiple rates can be supported in parallel with the support of a partition key (we first try to find the bucket to use for each incoming request, then we apply the rate limit).

Constructor Summary

Constructors

Constructor and Description
TokenBucketThrottlingStrategy(com.google.common.base.Ticker ticker, ScheduledExecutorService scheduledExecutor, org.forgerock.util.time.Duration cleaningInterval) Constructs a new TokenBucketThrottlingStrategy.

Method Summary

Modifier and Type	Method and Description
void	stop() Stop and free any resources needed by the strategy.
org.forgerock.util.promise.Promise<Long,org.forgerock.util.promise.NeverThrowsException>	throttle(String partitionKey, ThrottlingRate throttlingRate) Based on the given partitionKey and throttlingRate, return if the call is accepted or not.

Methods inherited from class java.lang.Object

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

Constructor Detail

TokenBucketThrottlingStrategy

public TokenBucketThrottlingStrategy(com.google.common.base.Ticker ticker,
                                     ScheduledExecutorService scheduledExecutor,
                                     org.forgerock.util.time.Duration cleaningInterval)

Constructs a new TokenBucketThrottlingStrategy.

Parameters:

ticker - the Ticker to use to follow the timeline.

scheduledExecutor - the ScheduledExecutorService used to schedule cleaning tasks.

cleaningInterval - the interval between 2 cleaning tasks.

Method Detail

throttle

public org.forgerock.util.promise.Promise<Long,org.forgerock.util.promise.NeverThrowsException> throttle(String partitionKey,
                                                                                                         ThrottlingRate throttlingRate)

Description copied from interface: ThrottlingStrategy

Based on the given partitionKey and throttlingRate, return if the call is accepted or not. The returned promise is succeeded with a value of 0 if the call is accepted. Any value greater than 0 means that the next call that could be accepted after value nanoseconds.

This method returns a promise as the decision to let this call going through can be queued and thus completed later. That may allow for example to queue the first calls and complete the returned promises at a constant rate.

Specified by:

throttle in interface ThrottlingStrategy

Parameters:

partitionKey - the key used to identify the different groups

throttlingRate - the throttling rate to apply

Returns:

a Promise meaning that the call is accepted (succeeds with 0) or refused (succeeds with value greater than 0)

stop

public void stop()

Description copied from interface: ThrottlingStrategy

Stop and free any resources needed by the strategy.

Specified by:

stop in interface ThrottlingStrategy