Move externalLoadBalancer setting to RiakNode

Author: Luke Bakken

src/RiakClient/Comms/IRiakNode.cs

@@ -28,6 +28,14 @@ namespace RiakClient.Comms
     /// </summary>
     public interface IRiakNode : IDisposable
     {
+        /// <summary>
+        /// Indicates if this node can be marked offline. <b>false</b> if the node points to a load balancer.
+        /// </summary>
+        /// <returns>
+        /// <b>true</b> or <b>false</b> depending on the node's configuration.
+        /// </returns>
+        bool CanMarkOffline { get; }
+
         /// <summary>
         /// Execute the <paramref name="useFun"/> delegate using this one of this <see cref="IRiakNode"/>'s connections.
         /// </summary>

src/RiakClient/Comms/RiakNode.cs

@@ -26,13 +26,16 @@ namespace RiakClient.Comms
     internal class RiakNode : IRiakNode
     {
         private readonly IRiakConnectionManager connections;
+        private readonly bool externalLoadBalancer = false;
         private bool disposing;
 
         public RiakNode(
             IRiakNodeConfiguration nodeConfig,
             IRiakAuthenticationConfiguration authConfig,
             IRiakConnectionFactory connectionFactory)
         {
+            externalLoadBalancer = nodeConfig.ExternalLoadBalancer;
+
             // assume that if the node has a pool size of 0 then the intent is to have the connections
             // made on the fly
             if (nodeConfig.PoolSize == 0)
@@ -45,6 +48,11 @@ public RiakNode(
             }
         }
 
+        public bool CanMarkOffline
+        {
+            get { return externalLoadBalancer == false; }
+        }
+
         public RiakResult UseConnection(Func<IRiakConnection, RiakResult> useFun)
         {
             return UseConnection(useFun, RiakResult.FromError);

src/RiakClient/Config/IRiakClusterConfiguration.cs

@@ -41,12 +41,6 @@ public interface IRiakClusterConfiguration
         /// </summary>
         Timeout DefaultRetryWaitTime { get; set; }
 
-        /// <summary>
-        /// If True and only one node is configured, the node (pointing to the load balancer) will not be marked offline and requests will always be routed to that node.
-        /// If False (default) offline nodes will be removed from the pool until health check determines they are healthy again.
-        /// </summary>
-        bool ExternalLoadBalancer { get; set; }
-
         /// <summary>
         /// The max number of retry attempts to make when the client encounters 
         /// <see cref="ResultCode"/>.NoConnections or <see cref="ResultCode"/>.CommunicationError errors.

src/RiakClient/Config/IRiakNodeConfiguration.cs

@@ -46,6 +46,12 @@ public interface IRiakNodeConfiguration
         /// </summary>
         int PoolSize { get; set; }
 
+        /// <summary>
+        /// If True, this node (pointing to a load balancer) will not be marked offline and requests will always be routed to it.
+        /// If False (default) and this node is offline, it will be removed from the pool until health check determines it is healthy again.
+        /// </summary>
+        bool ExternalLoadBalancer { get; set; }
+
         /// <summary>
         /// The network timeout to use when attempting to read data from Riak.
         /// </summary>

src/RiakClient/Config/RiakClusterConfiguration.cs

@@ -104,15 +104,6 @@ public int DefaultRetryCount
             set { this["defaultRetryCount"] = value; }
         }
 
-        /// <inheritdoc/>
-        /// <remarks>Defaults to False if omitted from the configuration file.</remarks>
-        [ConfigurationProperty("externalLoadBalancer", DefaultValue = "False", IsRequired = false)]
-        public bool ExternalLoadBalancer
-        {
-            get { return (bool)this["externalLoadBalancer"]; }
-            set { this["externalLoadBalancer"] = value; }
-        }
-
         /// <summary>
         /// A <see cref="IRiakAuthenticationConfiguration"/> configuration that details any authentication information.
         /// </summary>

src/RiakClient/Config/RiakNodeConfiguration.cs

@@ -72,6 +72,15 @@ public int PoolSize
          * }
          */
 
+        /// <inheritdoc/>
+        /// <remarks>Defaults to False if omitted from the configuration file.</remarks>
+        [ConfigurationProperty("externalLoadBalancer", DefaultValue = "False", IsRequired = false)]
+        public bool ExternalLoadBalancer
+        {
+            get { return (bool)this["externalLoadBalancer"]; }
+            set { this["externalLoadBalancer"] = value; }
+        }
+
         /// <inheritdoc/>
         /// <remarks>Defaults to 4000ms if omitted from the configuration file.</remarks>
         public Timeout NetworkReadTimeout

src/RiakClient/RiakCluster.cs

@@ -42,7 +42,6 @@ public class RiakCluster : RiakEndPoint
         private readonly ConcurrentQueue<IRiakNode> offlineNodes;
         private readonly TimeSpan nodePollTime;
         private readonly int defaultRetryCount;
-        private readonly bool externalLoadBalancer = false;
 
         private readonly CancellationTokenSource cts = new CancellationTokenSource();
         private readonly CancellationToken ct;
@@ -59,7 +58,6 @@ public class RiakCluster : RiakEndPoint
         public RiakCluster(IRiakClusterConfiguration clusterConfig, IRiakConnectionFactory connectionFactory)
         {
             nodePollTime = clusterConfig.NodePollTime;
-            externalLoadBalancer = clusterConfig.ExternalLoadBalancer;
             nodes = clusterConfig.RiakNodes.Select(rn =>
                 new RiakNode(rn, clusterConfig.Authentication, connectionFactory)).Cast<IRiakNode>().ToList();
             loadBalancer = new RoundRobinStrategy();
@@ -88,22 +86,6 @@ protected override int DefaultRetryCount
             get { return defaultRetryCount; }
         }
 
-        private bool CanMarkNodesOffline
-        {
-            get
-            {
-                // Assume OK to mark nodes offline.
-                bool rv = true;
-
-                if (externalLoadBalancer && nodes.Count == 1)
-                {
-                    rv = false; // Only one node configured and LB present, never mark it offline.
-                }
-
-                return rv;
-            }
-        }
-
         /// <summary>
         /// Creates an instance of <see cref="IRiakClient"/> populated from from the configuration section
         /// specified by <paramref name="configSectionName"/>.
@@ -260,7 +242,7 @@ protected override TRiakResult UseConnection<TRiakResult>(
 
         private void MaybeDeactivateNode(bool nodeOffline, IRiakNode node)
         {
-            if (nodeOffline && CanMarkNodesOffline)
+            if (nodeOffline && node.CanMarkOffline)
             {
                 lock (node)
                 {

src/RiakClientTests.Live/RiakConfigurationTests.cs

@@ -33,9 +33,9 @@ public class WhenLoadingFromExternalConfiguration
               <configSections>
                 <section name=""riakConfig"" type=""RiakClient.Config.RiakClusterConfiguration, RiakClient"" />
               </configSections>
-              <riakConfig nodePollTime=""5000"" defaultRetryWaitTime=""200"" defaultRetryCount=""3"" externalLoadBalancer=""true"">
+              <riakConfig nodePollTime=""5000"" defaultRetryWaitTime=""200"" defaultRetryCount=""3"">
                 <nodes>
-                  <node name=""node1"" hostAddress=""host1"" pbcPort=""8081"" poolSize=""5"" />
+                  <node name=""node1"" hostAddress=""host1"" pbcPort=""8081"" poolSize=""5"" externalLoadBalancer=""true"" />
                   <node name=""node2"" hostAddress=""host2"" pbcPort=""8081"" poolSize=""6""
                         networkReadTimeout=""5000"" networkWriteTimeout=""5000"" networkConnectTimeout=""5000"" />
                 </nodes>
@@ -73,14 +73,14 @@ public void ConfigurationLoadsProperly()
                 config.DefaultRetryWaitTime.ShouldEqual((Timeout)twoHundredMillis);
                 config.NodePollTime.ShouldEqual((Timeout)fiveSecsAsMillis);
                 config.RiakNodes.Count().ShouldEqual(2);
-                Assert.IsTrue(config.ExternalLoadBalancer);
 
                 var nodes = config.RiakNodes.ToArray();
                 IRiakNodeConfiguration node1 = nodes[0];
                 node1.Name.ShouldEqual("node1");
                 node1.HostAddress.ShouldEqual("host1");
                 node1.PbcPort.ShouldEqual(8081);
                 node1.PoolSize.ShouldEqual(5);
+                Assert.IsTrue(node1.ExternalLoadBalancer);
                 node1.NetworkConnectTimeout.ShouldEqual((Timeout)fourSecsAsMillis);
                 node1.NetworkReadTimeout.ShouldEqual((Timeout)fourSecsAsMillis);
                 node1.NetworkWriteTimeout.ShouldEqual((Timeout)fourSecsAsMillis);
@@ -90,6 +90,7 @@ public void ConfigurationLoadsProperly()
                 node2.HostAddress.ShouldEqual("host2");
                 node2.PbcPort.ShouldEqual(8081);
                 node2.PoolSize.ShouldEqual(6);
+                Assert.IsFalse(node2.ExternalLoadBalancer);
                 node2.NetworkConnectTimeout.ShouldEqual((Timeout)fiveSecsAsMillis);
                 node2.NetworkReadTimeout.ShouldEqual((Timeout)fiveSecsAsMillis);
                 node2.NetworkWriteTimeout.ShouldEqual((Timeout)fiveSecsAsMillis);
@@ -113,7 +114,6 @@ public void ConfigurationLoadsDefaults()
                 Assert.AreEqual(200, (int)config.DefaultRetryWaitTime);
                 Assert.AreEqual(5000, (int)config.NodePollTime);
                 Assert.AreEqual(1, config.RiakNodes.Count());
-                Assert.IsFalse(config.ExternalLoadBalancer);
 
                 var nodes = config.RiakNodes.ToArray();
                 IRiakNodeConfiguration node = nodes[0];