org.apache.hc.client5.http.impl.classic

Class LinearBackoffManager

java.lang.Object

org.apache.hc.client5.http.impl.classic.AbstractBackoff

org.apache.hc.client5.http.impl.classic.LinearBackoffManager

All Implemented Interfaces:

BackoffManager

@Contract(threading=SAFE)
public class LinearBackoffManager
extends AbstractBackoff

An implementation of BackoffManager that uses a linear backoff strategy to adjust the maximum number of connections per route in an PoolingHttpClientConnectionManager. This class is designed to be thread-safe and can be used in multi-threaded environments.

The linear backoff strategy increases or decreases the maximum number of connections per route by a fixed increment when backing off or probing, respectively. The adjustments are made based on a cool-down period, during which no further adjustments will be made.

The LinearBackoffManager is intended to be used with a PoolingHttpClientConnectionManager, which provides the ConnPoolControl interface. This class interacts with the PoolingHttpClientConnectionManager to adjust the maximum number of connections per route.

Example usage:

 PoolingHttpClientConnectionManager connectionManager = new PoolingHttpClientConnectionManager();
 LinearBackoffManager backoffManager = new LinearBackoffManager(connectionManager, 1);
 // Use the backoffManager with the connectionManager in your application
 

Since:

5.3

See Also:

BackoffManager, ConnPoolControl, PoolingHttpClientConnectionManager

Constructor Summary

Constructors

Constructor and Description
LinearBackoffManager(org.apache.hc.core5.pool.ConnPoolControl<HttpRoute> connPoolControl) Constructs a new LinearBackoffManager with the specified connection pool control.
LinearBackoffManager(org.apache.hc.core5.pool.ConnPoolControl<HttpRoute> connPoolControl, int increment) Constructs a new LinearBackoffManager with the specified connection pool control and backoff increment.

Method Summary

Modifier and Type	Method and Description
void	backOff(HttpRoute route) Reduces the number of maximum allowed connections for the specified route based on the exponential backoff algorithm.
protected int	getBackedOffPoolSize(int curr) Returns the new pool size after applying the linear backoff algorithm.
void	probe(HttpRoute route) Adjusts the maximum number of connections for the specified route, decreasing it by the increment value.
void	setBackoffFactor(double d) This method is not used in LinearBackoffManager's implementation.

Methods inherited from class org.apache.hc.client5.http.impl.classic.AbstractBackoff

getBackoffFactor, getCap, getConnPerRoute, getCoolDown, getLastRouteBackoffs, getLastRouteProbes, getLastUpdate, getTimeInterval, setCoolDown, setPerHostConnectionCap

Methods inherited from class java.lang.Object

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

Constructor Detail

LinearBackoffManager

public LinearBackoffManager(org.apache.hc.core5.pool.ConnPoolControl<HttpRoute> connPoolControl)

Constructs a new LinearBackoffManager with the specified connection pool control. The backoff increment is set to 1 by default.

Parameters:

connPoolControl - the connection pool control to be used by this LinearBackoffManager

LinearBackoffManager

public LinearBackoffManager(org.apache.hc.core5.pool.ConnPoolControl<HttpRoute> connPoolControl,
                            int increment)

Constructs a new LinearBackoffManager with the specified connection pool control and backoff increment.

Parameters:

connPoolControl - the connection pool control to be used by this LinearBackoffManager

increment - the backoff increment to be used when adjusting connection pool sizes

Throws:

IllegalArgumentException - if connPoolControl is null or increment is not positive

Method Detail

backOff

public void backOff(HttpRoute route)

Description copied from class: AbstractBackoff

Reduces the number of maximum allowed connections for the specified route based on the exponential backoff algorithm.

Specified by:

backOff in interface BackoffManager

Overrides:

backOff in class AbstractBackoff

Parameters:

route - the HttpRoute for which the backoff needs to be applied

probe

public void probe(HttpRoute route)

Adjusts the maximum number of connections for the specified route, decreasing it by the increment value. The method ensures that adjustments only happen after the cool-down period has passed since the last adjustment.

Specified by:

probe in interface BackoffManager

Overrides:

probe in class AbstractBackoff

Parameters:

route - the HttpRoute for which the maximum number of connections will be decreased

getBackedOffPoolSize

protected int getBackedOffPoolSize(int curr)

Returns the new pool size after applying the linear backoff algorithm. The new pool size is calculated by adding the increment value to the current pool size.

Specified by:

getBackedOffPoolSize in class AbstractBackoff

Parameters:

curr - the current pool size

Returns:

the new pool size after applying the linear backoff

setBackoffFactor

public void setBackoffFactor(double d)

This method is not used in LinearBackoffManager's implementation. It is provided to fulfill the interface requirement and for potential future extensions or modifications of LinearBackoffManager that may use the backoff factor.

Parameters:

d - the backoff factor, not used in the current implementation