Package io.deephaven.util

Class RetryBackoffContext.Exponential

java.lang.Object
io.deephaven.util.RetryBackoffContext.Exponential
All Implemented Interfaces:
RetryBackoffContext
Enclosing interface:
RetryBackoffContext
public static class RetryBackoffContext.Exponential extends Object implements RetryBackoffContext
Implementation based on an exponential backoff. Borrowing the retry backoff algorithm from gRPC reconnection

  • Field Details

  • Constructor Details

    • Exponential

      public Exponential(long initialDelayMillis, long maxDelayMillis, double backoffFactor, double jitterFactor)
      Create an exponential backoff RetryBackoffContext.
      Parameters:
      initialDelayMillis - Initial delay to retry. Subsequent retries happen at double the previous retry delay as long as that value does not exceed the max delay; when double the previous value would exceed the max delay and from then on the max delay is used.
      maxDelayMillis - max delay to apply; once the exponential increase of initial reaches this value, retries happen linearly at this value; they wait the same amount for every subsequent retry.
      backoffFactor - multiplier factor to apply to a delay to get the next delay; this factor is applied as long as the result is below the max delay, at that point each subsequent delay is that max delay.
      jitterFactor - a factor to apply to randomize the exact retry delay; a given calculated delay is randomized in the interval [(1-jitterFactor)*delay, (1+jitterFactor)*delay]

  • Method Details

    • start

      public void start(long timeOfDeadlineMillis)
      Description copied from interface: RetryBackoffContext
      Start tracking time to execute a backoff retry strategy using this context object. A deadline is defined when this method is called.
      Specified by:
      start in interface RetryBackoffContext
      Parameters:
      timeOfDeadlineMillis - absolute time as milliseconds from the epoch to the deadline.

    • startIfNotAlreadyStarted

      public void startIfNotAlreadyStarted(long timeOfDeadlineMillis)
      Description copied from interface: RetryBackoffContext
      If not already started, start tracking time to execute a backoff retry strategy using this context object exactly like RetryBackoffContext.start(long), including defining a deadline. If already started, this call does nothing.
      Specified by:
      startIfNotAlreadyStarted in interface RetryBackoffContext
      Parameters:
      timeOfDeadlineMillis - absolute time as milliseconds from the epoch to the deadline.

    • reset

      public void reset()
      Description copied from interface: RetryBackoffContext
      Reset this object to a state where no errors have occurred, and it has not been started.
      Specified by:
      reset in interface RetryBackoffContext

    • retryCount

      public int retryCount()
      Description copied from interface: RetryBackoffContext
      Number of retries performed since last started. Useful for clients that want to log a retry summary after deadline exceeded.
      Specified by:
      retryCount in interface RetryBackoffContext
      Returns:
      number of retries performed.

    • startMillis

      public long startMillis()
      Description copied from interface: RetryBackoffContext
      Absolute point in time when the last call to RetryBackoffContext.startMillis() was invoked.
      Specified by:
      startMillis in interface RetryBackoffContext
      Returns:
      a milliseconds from the epoch timestamp.

    • deadlineExceeded

      public boolean deadlineExceeded()
      Description copied from interface: RetryBackoffContext
      Check if we have exceeded our time deadline to retry.
      Specified by:
      deadlineExceeded in interface RetryBackoffContext
      Returns:
      true if the retry deadline has been exceeded, false otherwise.

    • noBackoff

      public void noBackoff()
      Description copied from interface: RetryBackoffContext
      Inform this context object that a retry without applying backoff will be performed.

      If the caller has some criteria to decide to perform retries in some cases without applying a backoff (eg, if a failure due to authentication requires to renew credentials, which makes sense to be done right away since we understand the reason for the failure), the calling this function lets this object keep the right context for the number of retries performed.

      If this method is called before a call to RetryBackoffContext.start(long) has been made, it will be equivalent to having made a call to start tracking time with an infinite deadline before the call.

      Specified by:
      noBackoff in interface RetryBackoffContext

    • backoffMillis

      public long backoffMillis()
      Description copied from interface: RetryBackoffContext
      Return the time in milliseconds to wait to the next retry. It is assumed the caller will perform a retry at that future point in time. Thread.sleep(long).

      If this method is called before a call to RetryBackoffContext.start(long) has been made, it will be equivalent to having made a call to start tracking time with an infinite deadline before the call, and the initial backoff returned would be zero; subsequent calls would return the initial backoff, and exponentially generated backoffs (as normal) from there.

      Specified by:
      backoffMillis in interface RetryBackoffContext
      Returns:
      time in milliseconds to wait until the next retry.

    • elapsedMillis

      public long elapsedMillis()
      Description copied from interface: RetryBackoffContext
      Return the elapsed between the last time to RetryBackoffContext.deadlineExceeded() and the last call to RetryBackoffContext.start(long).
      Specified by:
      elapsedMillis in interface RetryBackoffContext
      Returns:
      elapsed time in milliseconds.

    • timeOfDeadlineMillis

      public long timeOfDeadlineMillis()
      Description copied from interface: RetryBackoffContext
      Returns the absolute epoch time in milliseconds for the deadline. Note this method only returns a valid deadline if start has already been called on this Context.
      Specified by:
      timeOfDeadlineMillis in interface RetryBackoffContext
      Returns:
      epoch time of deadline in milliseconds.