Package org.apache.hc.client5.http.impl.schedule

Class ExponentialBackOffSchedulingStrategy

  • All Implemented Interfaces:
    SchedulingStrategy
    @Contract(threading=STATELESS)
public class ExponentialBackOffSchedulingStrategy
extends java.lang.Object
implements SchedulingStrategy
    An implementation that backs off exponentially based on the number of consecutive failed attempts. It uses the following defaults: 
          no delay in case it was never tried or didn't fail so far
     6 s delay for one failed attempt (= getInitialExpiry())
    60 s delay for two failed attempts
  10 min delay for three failed attempts
 100 min delay for four failed attempts
   ~16 h delay for five failed attempts
    24 h delay for six or more failed attempts (= getMaxExpiry())
    The following equation is used to calculate the delay for a specific pending operation: 
         delay = getInitialExpiry() * Math.pow(getBackOffRate(),
     consecutiveFailedAttempts - 1))
    The resulting delay won't exceed getMaxExpiry().
    Since:
    5.0

    • Field Detail

      • DEFAULT_INITIAL_EXPIRY

        public static final org.apache.hc.core5.util.TimeValue DEFAULT_INITIAL_EXPIRY

      • DEFAULT_MAX_EXPIRY

        public static final org.apache.hc.core5.util.TimeValue DEFAULT_MAX_EXPIRY

      • backOffRate

        private final long backOffRate

      • initialExpiry

        private final org.apache.hc.core5.util.TimeValue initialExpiry

      • maxExpiry

        private final org.apache.hc.core5.util.TimeValue maxExpiry

    • Constructor Detail

      • ExponentialBackOffSchedulingStrategy

        public ExponentialBackOffSchedulingStrategy​(long backOffRate,
                                            org.apache.hc.core5.util.TimeValue initialExpiry,
                                            org.apache.hc.core5.util.TimeValue maxExpiry)

      • ExponentialBackOffSchedulingStrategy

        public ExponentialBackOffSchedulingStrategy​(long backOffRate,
                                            org.apache.hc.core5.util.TimeValue initialExpiry)

      • ExponentialBackOffSchedulingStrategy

        public ExponentialBackOffSchedulingStrategy​(long backOffRate)

      • ExponentialBackOffSchedulingStrategy

        public ExponentialBackOffSchedulingStrategy()

    • Method Detail

      • schedule

        public org.apache.hc.core5.util.TimeValue schedule​(int attemptNumber)
        Description copied from interface: SchedulingStrategy
        Schedules execution time for an operation.
        Specified by:
        schedule in interface SchedulingStrategy

      • getBackOffRate

        public long getBackOffRate()

      • getInitialExpiry

        public org.apache.hc.core5.util.TimeValue getInitialExpiry()

      • getMaxExpiry

        public org.apache.hc.core5.util.TimeValue getMaxExpiry()

      • calculateDelay

        protected org.apache.hc.core5.util.TimeValue calculateDelay​(int consecutiveFailedAttempts)