c# - 从 Sentinel C# 获取 Redis Master 地址

Question

我正在尝试使用哨兵来获取我的主服务器的连接地址，问题是哨兵仅在故障转移时发送地址，但是如果我的主服务器关闭并且从服务器被提升为主服务器并且我的应用程序刚刚启动它不会知道并且不会得到原来master宕机的消息，有什么办法可以和sentinel交流，问他认为master在用C# servicestack redis客户端的是谁？

Answer 1

不得不以艰难的方式做到这一点，我使用下一个代码片段模仿 redis-cli 命令：（剩下的就是从响应中解析结果）

   public string GetMasterFromSentinel(string sentinelAddress)
    {
        TcpClient server;

        try
        {
            var splittedAddress = sentinelAddress.Split(':');
            server = new TcpClient(splittedAddress[0], splittedAddress[1].ParseInt());
        }
        catch (SocketException)
        {
            _log.Error("Unable to connect to server");
            return string.Empty;
        }
        NetworkStream ns = server.GetStream();
        var payload = new byte[] { 0x2a, 0x32, 0x0d, 0x0a, 0x24, 0x38, 0x0d, 0x0a, 0x73, 0x65, 0x6e, 0x74, 0x69, 0x6e, 0x65, 0x6c, 
                0x0d, 0x0a, 0x24, 0x37, 0x0d, 0x0a, 0x6d, 0x61, 0x73, 0x74, 0x65, 0x72, 0x73, 0x0d, 0x0a };
        ns.Write(payload, 0, payload.Length);
        ns.Flush();
        var data = new byte[1024];
        ns.Read(data, 0, data.Length);
        var recv = ns.Read(data, 0, data.Length);

        ns.Close();
        server.Close();
        return ParseResponse(data);
    }

Answer 2

我已经编写了一些测试代码来获取 Master 的 IP 和 Port --- 通过 Sentinel 的 IP 和端口（从机或主机都可以）。此代码使用来自 StackExchange.Redis 的 NuGet 包

using StackExchange.Redis;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net;
using System.Net.Sockets;
using System.Text;
using System.Threading;
using System.Threading.Tasks;

namespace Test
{
    public class Sentinel
    {
        private ConnectionMultiplexer Conn { get; }
        private IServer Server { get; }
        protected StringWriter ConnectionLog { get; }

        public Sentinel()
        {
            var options = new ConfigurationOptions()
            {
                CommandMap = CommandMap.Sentinel,
                EndPoints = { { "192.168.1.64", 26379 } },  //IP and Port of Sentinel
                AllowAdmin = true,
                TieBreaker = "",
                SyncTimeout = 5000
            };
            Conn = ConnectionMultiplexer.Connect(options, ConnectionLog);
            Server = Conn.GetServer("192.168.1.64", 26379); //IP and Port of Sentinel
        }

        public void SentinelGetMasterAddressByNameTest(string nameOfMaster)
        {
            var endpoint = Server.SentinelGetMasterAddressByName(nameOfMaster); 
            var ipEndPoint = endpoint as IPEndPoint;
            Console.WriteLine("The Master's <IP:Port>: {0}:{1}", ipEndPoint.Address, ipEndPoint.Port);
        }
    }



    class Program
    {

        static void Main(string[] args)
        {
           var sentinel = new Sentinel();
           sentinel.SentinelGetMasterAddressByNameTest("redis-test"); //Passing name of the master
           Console.ReadLine();
        }
    }
}