/// <summary>
/// Generates the circuit breaker policy for a service.
/// </summary>
/// <param name="serviceInfo">The service to generate the circuit breaker policy for</param>
/// <returns>The circuit policy</returns>
protected AsyncPolicyWrap <ServiceResponse> GetCircuitBreakerPolicy(CalledServiceInfo serviceInfo)
{
return(CircuitBreakerPolicies.GetOrAdd(serviceInfo.CacheKey, _ =>
{
AsyncTimeoutPolicy timeoutPolicy = Policy
.TimeoutAsync(
serviceInfo.Timeout,
TimeoutStrategy.Pessimistic
);
AsyncCircuitBreakerPolicy <ServiceResponse> circuitBreakerPolicy = Policy <ServiceResponse>
.Handle <TimeoutRejectedException>()
.OrResult(resultPredicate: serviceResponse => serviceResponse.Status == ServiceResponseStatus.Error)
.CircuitBreakerAsync(
handledEventsAllowedBeforeBreaking: serviceInfo.CircuitBreakerInfo.ExceptionCount,
durationOfBreak: serviceInfo.CircuitBreakerInfo.BreakDuration,
onBreak: (__, ___) =>
{
Log.Warning("Service ({ServiceName}) has reached its threshold for the circuit breaker and the circuit has been opened", serviceInfo.Name);
},
onReset: () =>
{
Log.Warning("Service ({ServiceName}) has been determined to be back up, circuit closed again", serviceInfo.Name);
}
);
AsyncPolicyWrap <ServiceResponse> circuitBreakerWrappingTimeout = circuitBreakerPolicy
.WrapAsync(timeoutPolicy);
AsyncFallbackPolicy <ServiceResponse> timeoutFallbackPolicy = Policy <ServiceResponse>
.Handle <TimeoutRejectedException>()
.FallbackAsync(
cancellationToken =>
{
return Task.FromResult(new ServiceResponse
{
Status = ServiceResponseStatus.Timeout,
ServiceId = serviceInfo.Id
});
});
AsyncPolicyWrap <ServiceResponse> timeoutFallbackPolicyWrappingCircuitBreaker = timeoutFallbackPolicy
.WrapAsync(circuitBreakerWrappingTimeout);
AsyncFallbackPolicy <ServiceResponse> exceptionFallbackPolicy = Policy <ServiceResponse>
.Handle <Exception>()
.FallbackAsync(
cancellationToken =>
{
return Task.FromResult(new ServiceResponse
{
Status = ServiceResponseStatus.Error,
ServiceId = serviceInfo.Id
});
});
AsyncPolicyWrap <ServiceResponse> exceptionFallbackPolicyWrappingTimeoutFallback = exceptionFallbackPolicy
.WrapAsync(timeoutFallbackPolicyWrappingCircuitBreaker);
AsyncPolicyWrap <ServiceResponse> policy = exceptionFallbackPolicyWrappingTimeoutFallback;
return policy;
}));
}
/// <summary>
/// Policy Resiliance Strategy
/// </summary>
/// <returns></returns>
public AsyncPolicy GetResillianceStrategy()
{
return(_circuitBreakerPolicy.WrapAsync(_retryPolicy.WrapAsync(_bulkheadPolicy)));
}