Module io.helidon.faulttolerance
Package io.helidon.faulttolerance

Class CircuitBreaker.Builder

java.lang.Object
io.helidon.faulttolerance.CircuitBreaker.Builder
All Implemented Interfaces:
Builder<CircuitBreaker.Builder,CircuitBreaker>, Supplier<CircuitBreaker>
Enclosing interface:
CircuitBreaker
public static class CircuitBreaker.Builder extends Object implements Builder<CircuitBreaker.Builder,CircuitBreaker>
Fluent API builder for CircuitBreaker.

  • Method Details

    • build

      public CircuitBreaker build()
      Description copied from interface: Builder
      Build the instance from this builder.
      Specified by:
      build in interface Builder<CircuitBreaker.Builder,CircuitBreaker>
      Returns:
      instance of the built type

    • delay

      public CircuitBreaker.Builder delay(Duration delay)
      How long to wait before transitioning from open to half-open state.
      Parameters:
      delay - to wait
      Returns:
      updated builder instance

    • errorRatio

      public CircuitBreaker.Builder errorRatio(int ratio)
      How many failures out of 100 will trigger the circuit to open. This is adapted to the volume(int) used to handle the window of requests.

      If errorRatio is 40, and volume is 10, 4 failed requests will open the circuit.

      Parameters:
      ratio - percent of failure that trigger the circuit to open
      Returns:
      updated builder instance
      See Also:

    • successThreshold

      public CircuitBreaker.Builder successThreshold(int successThreshold)
      How many successful calls will close a half-open circuit. Nevertheless the first failed call will open the circuit again.
      Parameters:
      successThreshold - number of calls
      Returns:
      updated builder instance

    • volume

      public CircuitBreaker.Builder volume(int volume)
      Rolling window size used to calculate ratio of failed requests.
      Parameters:
      volume - how big a window is used to calculate error errorRatio
      Returns:
      updated builder instance
      See Also:

    • applyOn

      @SafeVarargs public final CircuitBreaker.Builder applyOn(Class<? extends Throwable>... classes)
      These throwables will be considered failures, and all other will not.

      Cannot be combined with skipOn.

      Parameters:
      classes - to consider failures to calculate failure ratio
      Returns:
      updated builder instance

    • addApplyOn

      public CircuitBreaker.Builder addApplyOn(Class<? extends Throwable> clazz)
      Add a throwable to be considered a failure.
      Parameters:
      clazz - to consider failure to calculate failure ratio
      Returns:
      updated builder instance
      See Also:
      • applyOn

    • skipOn

      @SafeVarargs public final CircuitBreaker.Builder skipOn(Class<? extends Throwable>... classes)
      These throwables will not be considered failures, all other will.

      Cannot be combined with applyOn.

      Parameters:
      classes - to consider successful
      Returns:
      updated builder instance

    • addSkipOn

      public CircuitBreaker.Builder addSkipOn(Class<? extends Throwable> clazz)
      This throwable will not be considered failure.

      Parameters:
      clazz - to consider successful
      Returns:
      updated builder instance

    • executor

      public CircuitBreaker.Builder executor(ScheduledExecutorService scheduledExecutor)
      Executor service to schedule future tasks. By default uses an executor configured on FaultTolerance.scheduledExecutor(java.util.function.Supplier).
      Parameters:
      scheduledExecutor - executor to use
      Returns:
      updated builder instance

    • name

      public CircuitBreaker.Builder name(String name)
      A name assigned for debugging, error reporting or configuration purposes.
      Parameters:
      name - the name
      Returns:
      updated builder instance

    • cancelSource

      public CircuitBreaker.Builder cancelSource(boolean cancelSource)
      Policy to cancel any source stage if the value return by FtHandler.invoke(java.util.function.Supplier<? extends java.util.concurrent.CompletionStage<T>>) is cancelled. Default is true; mostly used by FT MP to change default.
      Parameters:
      cancelSource - cancel source policy
      Returns:
      updated builder instance

    • config

      public CircuitBreaker.Builder config(Config config)

      Load all properties for this circuit breaker from configuration.

      Configuration
      key default value description
      delay 5 seconds Delay to transition from open to half-open
      name CircuitBreaker-N Name used for debugging
      error-ratio 60 Failure percentage that will open the breaker
      success-threshold 1 Number of successful calls will close a half-open breaker
      volume 10 Rolling window size
      cancel-source true Cancel task source if task is cancelled
      Parameters:
      config - the config node to use
      Returns:
      updated builder instance