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:

  • Constructor Details

    • 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 Details

    • 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