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