|
|
|
@ -24,76 +24,74 @@ namespace WebMVC.Services.Utilities |
|
|
|
CreateRetryPolicy(), |
|
|
|
CreateCircuitBreakerPolicy() |
|
|
|
); |
|
|
|
} |
|
|
|
|
|
|
|
private Policy CreateCircuitBreakerPolicy() |
|
|
|
{ |
|
|
|
return Policy |
|
|
|
.Handle<HttpRequestException>() |
|
|
|
.CircuitBreakerAsync( |
|
|
|
// number of exceptions before breaking circuit
|
|
|
|
5, |
|
|
|
// time circuit opened before retry
|
|
|
|
TimeSpan.FromMinutes(1), |
|
|
|
(exception, duration) => { |
|
|
|
// on circuit opened
|
|
|
|
_logger.LogTrace("Circuit breaker opened"); |
|
|
|
}, |
|
|
|
() => { |
|
|
|
// on circuit closed
|
|
|
|
_logger.LogTrace("Circuit breaker reset"); |
|
|
|
} |
|
|
|
); |
|
|
|
} |
|
|
|
|
|
|
|
private Policy CreateRetryPolicy() |
|
|
|
{ |
|
|
|
return Policy |
|
|
|
.Handle<HttpRequestException>() |
|
|
|
.WaitAndRetryAsync( |
|
|
|
// number of retries
|
|
|
|
5, |
|
|
|
// exponential backofff
|
|
|
|
retryAttempt => TimeSpan.FromSeconds(Math.Pow(2, retryAttempt)), |
|
|
|
// on retry
|
|
|
|
(exception, timeSpan, retryCount, context) => |
|
|
|
{ |
|
|
|
_logger.LogTrace($"Retry {retryCount} " + |
|
|
|
$"of {context.PolicyKey} " + |
|
|
|
$"at {context.ExecutionKey}, " + |
|
|
|
$"due to: {exception}."); |
|
|
|
}); |
|
|
|
} |
|
|
|
private Policy CreateCircuitBreakerPolicy() => |
|
|
|
Policy.Handle<HttpRequestException>() |
|
|
|
.CircuitBreakerAsync( |
|
|
|
// number of exceptions before breaking circuit
|
|
|
|
3, |
|
|
|
// time circuit opened before retry
|
|
|
|
TimeSpan.FromMinutes(1), |
|
|
|
(exception, duration) => |
|
|
|
{ |
|
|
|
// on circuit opened
|
|
|
|
_logger.LogTrace("Circuit breaker opened"); |
|
|
|
}, |
|
|
|
() => |
|
|
|
{ |
|
|
|
// on circuit closed
|
|
|
|
_logger.LogTrace("Circuit breaker reset"); |
|
|
|
} |
|
|
|
); |
|
|
|
|
|
|
|
public async Task<string> GetStringAsync(string uri) |
|
|
|
{ |
|
|
|
return await HttpInvoker(async () => |
|
|
|
await _client.GetStringAsync(uri)); |
|
|
|
} |
|
|
|
private Policy CreateRetryPolicy() => |
|
|
|
Policy.Handle<HttpRequestException>() |
|
|
|
.WaitAndRetryAsync( |
|
|
|
// number of retries
|
|
|
|
3, |
|
|
|
// exponential backofff
|
|
|
|
retryAttempt => TimeSpan.FromSeconds(Math.Pow(2, retryAttempt)), |
|
|
|
// on retry
|
|
|
|
(exception, timeSpan, retryCount, context) => |
|
|
|
{ |
|
|
|
_logger.LogTrace($"Retry {retryCount} " + |
|
|
|
$"of {context.PolicyKey} " + |
|
|
|
$"at {context.ExecutionKey}, " + |
|
|
|
$"due to: {exception}."); |
|
|
|
} |
|
|
|
); |
|
|
|
|
|
|
|
public async Task<HttpResponseMessage> PostAsync<T>(string uri, T item) |
|
|
|
{ |
|
|
|
// Notice that these (and other methods below) are Task
|
|
|
|
// returning asynchronous methods. But, they do not
|
|
|
|
// have the 'async' modifier, and do not contain
|
|
|
|
// any 'await statements. In each of these methods,
|
|
|
|
// the only asynchronous call is the last (or only)
|
|
|
|
// statement of the method. In those instances,
|
|
|
|
// a Task returning method that does not use the
|
|
|
|
// async modifier is preferred. The compiler generates
|
|
|
|
// synchronous code for this method, but returns the
|
|
|
|
// task from the underlying asynchronous method. The
|
|
|
|
// generated code does not contain the state machine
|
|
|
|
// generated for asynchronous methods.
|
|
|
|
public Task<string> GetStringAsync(string uri) => |
|
|
|
HttpInvoker(() => _client.GetStringAsync(uri)); |
|
|
|
|
|
|
|
public Task<HttpResponseMessage> PostAsync<T>(string uri, T item) => |
|
|
|
// a new StringContent must be created for each retry
|
|
|
|
// as it is disposed after each call
|
|
|
|
return await HttpInvoker(async () => |
|
|
|
await _client.PostAsync(uri, |
|
|
|
new StringContent(JsonConvert.SerializeObject(item), |
|
|
|
System.Text.Encoding.UTF8, "application/json"))); |
|
|
|
} |
|
|
|
HttpInvoker(() =>_client.PostAsync(uri, |
|
|
|
new StringContent(JsonConvert.SerializeObject(item), |
|
|
|
System.Text.Encoding.UTF8, "application/json"))); |
|
|
|
|
|
|
|
public async Task<HttpResponseMessage> DeleteAsync(string uri) |
|
|
|
{ |
|
|
|
return await HttpInvoker(async () => |
|
|
|
await _client.DeleteAsync(uri)); |
|
|
|
} |
|
|
|
public Task<HttpResponseMessage> DeleteAsync(string uri) => |
|
|
|
HttpInvoker(() => _client.DeleteAsync(uri)); |
|
|
|
|
|
|
|
private async Task<T> HttpInvoker<T>(Func<Task<T>> action) |
|
|
|
{ |
|
|
|
|
|
|
|
private Task<T> HttpInvoker<T>(Func<Task<T>> action) => |
|
|
|
// Executes the action applying all
|
|
|
|
// the policies defined in the wrapper
|
|
|
|
return await _policyWrapper |
|
|
|
.ExecuteAsync(async () => await action()); |
|
|
|
} |
|
|
|
_policyWrapper.ExecuteAsync(() => action()); |
|
|
|
} |
|
|
|
|
|
|
|
} |
Ramón Tomás
8 years ago