Sentinel: Several break fixes (#1402)

* fix naming of SentinelGetSentinelAddressesAsync

* tyop

* Sentinel: don't use async over sync with .Result
Co-authored-by: mgravell <marc.gravell@gmail.com>

src/StackExchange.Redis/ConnectionMultiplexer.cs

@@ -2303,53 +2303,16 @@ internal void OnManagedConnectionFailed(object sender, ConnectionFailedEventArgs
                 {
                     SwitchMaster(e.EndPoint, connection);
                 }, null, TimeSpan.FromSeconds(0), TimeSpan.FromSeconds(1));
-
-                //connection.sentinelMasterReconnectTimer.AutoReset = true;                            
-
-                //connection.sentinelMasterReconnectTimer.Start();
             }
         }
 
-        internal EndPoint GetConfiguredMasterForService(string serviceName, int timeoutmillis = -1)
-        {
-            Task<EndPoint>[] sentinelMasters = GetServerSnapshot().ToArray()
-                        .Where(s => s.ServerType == ServerType.Sentinel)
-                        .Select(s => GetServer(s.EndPoint).SentinelGetMasterAddressByNameAsync(serviceName))
-                        .ToArray();
-
-            Task<Task<EndPoint>> firstCompleteRequest = WaitFirstNonNullIgnoreErrorsAsync(sentinelMasters);
-            if (!firstCompleteRequest.Wait(timeoutmillis))
-                throw new TimeoutException("Timeout resolving master for service");
-            if (firstCompleteRequest.Result?.Result == null)
-                throw new Exception("Unable to determine master");
-
-            return firstCompleteRequest.Result.Result;
-        }
-
-        private static async Task<Task<T>> WaitFirstNonNullIgnoreErrorsAsync<T>(Task<T>[] tasks)
-        {
-            if (tasks == null) throw new ArgumentNullException("tasks");
-            if (tasks.Length == 0) return null;
-            var typeNullable = (Nullable.GetUnderlyingType(typeof(T)) != null);
-            var taskList = tasks.Cast<Task>().ToList();
-
-            try
-            {
-                while (taskList.Count > 0)
-                {
-                    var allTasksAwaitingAny = Task.WhenAny(taskList).ObserveErrors();
-                    var result = await allTasksAwaitingAny.ForAwait();
-                    taskList.Remove((Task<T>)result);
-                    if (((Task<T>)result).IsFaulted) continue;
-                    if ((!typeNullable) || ((Task<T>)result).Result != null)
-                        return (Task<T>)result;
-                }
-            }
-            catch
-            { }
-
-            return null;
-        }
+        internal EndPoint GetConfiguredMasterForService(string serviceName) =>
+            GetServerSnapshot()
+                .ToArray()
+                .Where(s => s.ServerType == ServerType.Sentinel)
+                .AsParallel()
+                .Select(s => GetServer(s.EndPoint).SentinelGetMasterAddressByName(serviceName))
+                .First(r => r != null);
 
         internal EndPoint currentSentinelMasterEndPoint;
 
@@ -2419,26 +2382,22 @@ private T Retry<T>(int times, int interval, Func<T> func, string message)
             throw new NullReferenceException(message);
         }
 
-        internal void UpdateSentinelAddressList(string serviceName, int timeoutmillis = 500)
+        internal void UpdateSentinelAddressList(string serviceName)
         {
-            Task<EndPoint[]>[] sentinels = GetServerSnapshot().ToArray()
-                        .Where(s => s.ServerType == ServerType.Sentinel)
-                        .Select(s => GetServer(s.EndPoint).SentinelGetSentinelAddresses(serviceName))
-                        .ToArray();
-
-            Task<Task<EndPoint[]>> firstCompleteRequest = WaitFirstNonNullIgnoreErrorsAsync(sentinels);
+            var firstCompleteRequest = GetServerSnapshot()
+                                        .ToArray()
+                                        .Where(s => s.ServerType == ServerType.Sentinel)
+                                        .AsParallel()
+                                        .Select(s => GetServer(s.EndPoint).SentinelGetSentinelAddresses(serviceName))
+                                        .First(r => r != null);
 
             // Ignore errors, as having an updated sentinel list is
             // not essential
-            if (firstCompleteRequest.Result?.Result == null)
-                return;
-            if (!firstCompleteRequest.Wait(timeoutmillis))
-                return;
-            if (firstCompleteRequest.Result.Result == null)
+            if (firstCompleteRequest == null)
                 return;
 
             bool hasNew = false;
-            foreach (EndPoint newSentinel in firstCompleteRequest.Result.Result.Where(x => !RawConfig.EndPoints.Contains(x)))
+            foreach (EndPoint newSentinel in firstCompleteRequest.Where(x => !RawConfig.EndPoints.Contains(x)))
             {
                 hasNew = true;
                 RawConfig.EndPoints.Add(newSentinel);

src/StackExchange.Redis/Interfaces/IServer.cs

@@ -756,10 +756,19 @@ public partial interface IServer : IRedis
         /// Returns the ip and port numbers of all known Sentinels
         /// for the given service name.
         /// </summary>
-        /// <param name="serviveName">the sentinel service name</param>
+        /// <param name="serviceName">the sentinel service name</param>
         /// <param name="flags"></param>
         /// <returns>a list of the sentinel ips and ports</returns>
-        Task<EndPoint[]> SentinelGetSentinelAddresses(string serviveName, CommandFlags flags = CommandFlags.None);
+        EndPoint[] SentinelGetSentinelAddresses(string serviceName, CommandFlags flags = CommandFlags.None);
+
+        /// <summary>
+        /// Returns the ip and port numbers of all known Sentinels
+        /// for the given service name.
+        /// </summary>
+        /// <param name="serviceName">the sentinel service name</param>
+        /// <param name="flags"></param>
+        /// <returns>a list of the sentinel ips and ports</returns>
+        Task<EndPoint[]> SentinelGetSentinelAddressesAsync(string serviceName, CommandFlags flags = CommandFlags.None);
 
         /// <summary>
         /// Show the state and info of the specified master.

src/StackExchange.Redis/RedisServer.cs

@@ -807,10 +807,16 @@ public Task<EndPoint> SentinelGetMasterAddressByNameAsync(string serviceName, Co
             return ExecuteAsync(msg, ResultProcessor.SentinelMasterEndpoint);
         }
 
-        public Task<EndPoint[]> SentinelGetSentinelAddresses(string serviceName, CommandFlags flags = CommandFlags.None)
+        public EndPoint[] SentinelGetSentinelAddresses(string serviceName, CommandFlags flags = CommandFlags.None)
         {
             var msg = Message.Create(-1, flags, RedisCommand.SENTINEL, RedisLiterals.SENTINELS, (RedisValue)serviceName);
-            return ExecuteAsync(msg, ResultProcessor.SentinelAddressesEndPoints);            
+            return ExecuteSync(msg, ResultProcessor.SentinelAddressesEndPoints);
+        }
+
+        public Task<EndPoint[]> SentinelGetSentinelAddressesAsync(string serviceName, CommandFlags flags = CommandFlags.None)
+        {
+            var msg = Message.Create(-1, flags, RedisCommand.SENTINEL, RedisLiterals.SENTINELS, (RedisValue)serviceName);
+            return ExecuteAsync(msg, ResultProcessor.SentinelAddressesEndPoints);
         }
 
         public KeyValuePair<string, string>[] SentinelMaster(string serviceName, CommandFlags flags = CommandFlags.None)

tests/StackExchange.Redis.Tests/Sentinel.cs

@@ -562,15 +562,15 @@ public async Task GetSentinelMasterConnectionWriteReadFailover()
         [Fact]
         public async Task SentinelGetSentinelAddressesTest()
         {
-            var addresses = await SentinelServerA.SentinelGetSentinelAddresses(ServiceName).ForAwait();
+            var addresses = await SentinelServerA.SentinelGetSentinelAddressesAsync(ServiceName).ForAwait();
             Assert.Contains(SentinelServerB.EndPoint, addresses);
             Assert.Contains(SentinelServerC.EndPoint, addresses);
 
-            addresses = await SentinelServerB.SentinelGetSentinelAddresses(ServiceName).ForAwait();
+            addresses = await SentinelServerB.SentinelGetSentinelAddressesAsync(ServiceName).ForAwait();
             Assert.Contains(SentinelServerA.EndPoint, addresses);
             Assert.Contains(SentinelServerC.EndPoint, addresses);
 
-            addresses = await SentinelServerC.SentinelGetSentinelAddresses(ServiceName).ForAwait();
+            addresses = await SentinelServerC.SentinelGetSentinelAddressesAsync(ServiceName).ForAwait();
             Assert.Contains(SentinelServerA.EndPoint, addresses);
             Assert.Contains(SentinelServerB.EndPoint, addresses);
         }