#2080 Adds parameters (in this case those of Polly V8) to fine-tune circuit-breaker behavior

Author: RaynaldM

src/Ocelot.Provider.Polly/PollyQoSResiliencePipelineProvider.cs

@@ -81,8 +81,8 @@ protected virtual ResiliencePipelineBuilder<HttpResponseMessage> ConfigureCircui
         var info = $"Circuit Breaker for Route: {GetRouteName(route)}: ";
         var strategyOptions = new CircuitBreakerStrategyOptions<HttpResponseMessage>
         {
-            FailureRatio = 0.8,
-            SamplingDuration = TimeSpan.FromSeconds(10),
+            FailureRatio = options.FailureRatio,
+            SamplingDuration = TimeSpan.FromSeconds(options.SamplingDuration),
             MinimumThroughput = options.ExceptionsAllowedBeforeBreaking,
             BreakDuration = options.DurationOfBreak > QoSOptions.LowBreakDuration
                 ? TimeSpan.FromMilliseconds(options.DurationOfBreak)

src/Ocelot/Configuration/QoSOptions.cs

@@ -23,7 +23,7 @@ public QoSOptions(FileQoSOptions from)
         public QoSOptions(
             int exceptionsAllowedBeforeBreaking,
             int durationOfBreak,
-            int timeoutValue, 
+            int timeoutValue,
             string key)
         {
             DurationOfBreak = durationOfBreak;
@@ -32,6 +32,36 @@ public QoSOptions(
             TimeoutValue = timeoutValue;
         }
 
+        public QoSOptions(
+            int exceptionsAllowedBeforeBreaking,
+            int durationOfBreak,
+            double failureRatio,
+            int timeoutValue,
+            string key)
+        {
+            DurationOfBreak = durationOfBreak;
+            ExceptionsAllowedBeforeBreaking = exceptionsAllowedBeforeBreaking;
+            Key = key;
+            TimeoutValue = timeoutValue;
+            FailureRatio = failureRatio;
+        }
+
+        public QoSOptions(
+            int exceptionsAllowedBeforeBreaking,
+            int durationOfBreak,
+            double failureRatio,
+            int samplingDuration,
+            int timeoutValue,
+           string key)
+        {
+            DurationOfBreak = durationOfBreak;
+            ExceptionsAllowedBeforeBreaking = exceptionsAllowedBeforeBreaking;
+            Key = key;
+            TimeoutValue = timeoutValue;
+            FailureRatio = failureRatio;
+            SamplingDuration = samplingDuration;
+        }
+
         /// <summary>How long the circuit should stay open before resetting in milliseconds.</summary>
         /// <remarks>If using Polly version 8 or above, this value must be 500 (0.5 sec) or greater.</remarks>
         /// <value>An <see cref="int"/> value (milliseconds).</value>
@@ -50,6 +80,22 @@ public QoSOptions(
         /// </value>
         public int ExceptionsAllowedBeforeBreaking { get; }
 
+        /// <summary>
+        /// The failure-success ratio that will cause the circuit to break/open. 
+        /// </summary>
+        /// <value>
+        /// An <see cref="double"/> 0.8 means 80% failed of all sampled executions.
+        /// </value>
+        public double FailureRatio { get; } = .8;
+
+        /// <summary>
+        /// The time period over which the failure-success ratio is calculated (in seconds).
+        /// </summary>
+        /// <value>
+        /// An <see cref="int"/> Time period in seconds, 10 means 10 seconds.
+        /// </value>
+        public int SamplingDuration { get; } = 10;
+
         public string Key { get; }
 
         /// <summary>

test/Ocelot.AcceptanceTests/PollyQoSTests.cs

@@ -38,7 +38,7 @@ public override void Dispose()
     public void Should_not_timeout()
     {
         var port = PortFinder.GetRandomPort();
-        var route = GivenRoute(port, new QoSOptions(10, 500, 1000, null), HttpMethods.Post);
+        var route = GivenRoute(port, new QoSOptions(10, 500, .5, 5, 1000, null), HttpMethods.Post);
         var configuration = GivenConfiguration(route);
 
         this.Given(x => x.GivenThereIsAServiceRunningOn(port, HttpStatusCode.OK, string.Empty, 10))
@@ -186,7 +186,7 @@ public void Should_timeout_per_default_after_90_seconds()
         var port = PortFinder.GetRandomPort();
         var route = GivenRoute(port, new QoSOptions(new FileQoSOptions()), HttpMethods.Get);
         var configuration = GivenConfiguration(route);
-
+
         this.Given(x => x.GivenThereIsAServiceRunningOn(port, HttpStatusCode.Created, string.Empty, 3500)) // 3.5s > 3s -> ServiceUnavailable
             .And(x => GivenThereIsAConfiguration(configuration))
             .And(x => GivenOcelotIsRunningWithPolly())