HttpClientHttpRequester implements the Circuit Breaker Pattern

HttpClientHttpRequester implements the Circuit Breaker Pattern，I using
Polly from thepollyproject.org

src/Ocelot/Requester/HttpClientHttpRequester.cs

@@ -4,22 +4,58 @@ using System.Net.Http;
 using System.Threading.Tasks;
 using Ocelot.Errors;
 using Ocelot.Responses;
+using Polly;
+using Polly.Timeout;
+using Polly.CircuitBreaker;
+using Ocelot.Logging;
 
 namespace Ocelot.Requester
 {
     public class HttpClientHttpRequester : IHttpRequester
     {
+        private readonly IOcelotLogger _logger;
+
+        public HttpClientHttpRequester(IOcelotLoggerFactory loggerFactory)
+        {
+            _logger = loggerFactory.CreateLogger<HttpClientHttpRequester>();
+        }
+
         public async Task<Response<HttpResponseMessage>> GetResponse(Request.Request request)
         {
+            double timeoutvalue = 5000;
+            TimeoutStrategy timeoutStrategy = TimeoutStrategy.Pessimistic;
+
+            var timeoutPolicy = Policy
+            .TimeoutAsync(TimeSpan.FromMilliseconds(timeoutvalue), timeoutStrategy);
+
+            var circuitBreakerPolicy = Policy
+                .Handle<Exception>()
+                .Or<TimeoutRejectedException>()
+                .Or<TimeoutException>()
+                .CircuitBreakerAsync(
+                    exceptionsAllowedBeforeBreaking: 4,
+                    durationOfBreak: TimeSpan.FromSeconds(8),
+                    onBreak: (ex, breakDelay) =>
+                    {
+                        _logger.LogError(".Breaker logging: Breaking the circuit for " + breakDelay.TotalMilliseconds + "ms!", ex);
+                    },
+                    onReset: () => _logger.LogDebug(".Breaker logging: Call ok! Closed the circuit again."),
+                    onHalfOpen: () => _logger.LogDebug(".Breaker logging: Half-open; next call is a trial.")
+                    );
+
             using (var handler = new HttpClientHandler { CookieContainer = request.CookieContainer })
             using (var httpClient = new HttpClient(handler))
             {
                 try
                 {
-                    var response = await httpClient.SendAsync(request.HttpRequestMessage);
+                    // Retry the following call according to the policy - 3 times.
+                    HttpResponseMessage response = await Policy.WrapAsync(circuitBreakerPolicy, timeoutPolicy).ExecuteAsync<HttpResponseMessage>(() =>
+                    {
+                        return httpClient.SendAsync(request.HttpRequestMessage);
+                    });
                     return new OkResponse<HttpResponseMessage>(response);
                 }
-                catch (Exception exception)
+                catch (BrokenCircuitException exception)
                 {
                     return
                         new ErrorResponse<HttpResponseMessage>(new List<Error>

src/Ocelot/project.json

@@ -27,7 +27,8 @@
     "Microsoft.NETCore.App": "1.1.0",
     "CacheManager.Core": "0.9.2",
     "CacheManager.Microsoft.Extensions.Configuration": "0.9.2",
-    "CacheManager.Microsoft.Extensions.Logging": "0.9.2"
+    "CacheManager.Microsoft.Extensions.Logging": "0.9.2",
+    "Polly": "5.0.3"
   },
   "runtimes": {
     "win10-x64": {},