Thrift搭建分布式微服务(二)

第二篇 连接池

    连接池配置,请前往Thrift搭建分布式微服务(一)

    下面要介绍的其实不是单一的连接池,应该说是连接池集合。因为它要管理多个Tcp Socket连接节点,每个服务节点都有设置了自己的最大激活连接数、最大空闲连接数、最小空闲连接数、等待连接时间。

 1     internal class ServiceTransportPool
 2     {
 3         public ServiceConfig ServiceConfig { get; set; }
 4 
 5         public ConcurrentStack TransportPool { get; set; }
 6 
 7         public AutoResetEvent ResetEvent { get; set; }
 8 
 9         public int ActivedTransportCount { get; set; }
     
     internal object sync_obeject = new object();
10 }

  

        一个ServiceTransportPool类对应一个服务配置,一个服务配置对应一个服务节点。连接池集合应具有下列成员:

1     internal class ThriftFactory
2     {
3         private static volatile List transport_pools;
4         
5         private static object sync_obj = new object();
6 
7         private static IThriftFactoryMonitor monitor = new ThriftFactoryMonitor();
8     }

        transport_pools实现了对服务节点的管理,monitor 用来监控连接池的状态,如上一篇所讲,等待连接超时怎么通知连接池管理者,就用monitor来实现。这里monitor有个默认的实现,后面再讲。

        初始化连接池集合:

 1         static ThriftFactory()
 2         {
 3             if (transport_pools == null || transport_pools.Count == 0)
 4             {
 5                 lock (sync_obj)
 6                 {
 7                     if (transport_pools == null || transport_pools.Count == 0)
 8                     {
 9                         var services = ConfigHelper.GetServiceConfigs();
10                         transport_pools = new List(services.Count);
11                         foreach (var service in services)
12                         {
13                             ServiceTransportPool stp = new ServiceTransportPool()
14                             {
15                                 ServiceConfig = service,
16                                 TransportPool = new ConcurrentStack(),
17                                 ResetEvent = new AutoResetEvent(false),
18                                 ActivedTransportCount = 0
19                             };
20                             transport_pools.Add(stp);
21                         }
22                     }
23                 }
24             }
25        }

 

   如何向连接池借出一个Socket连接:

 1         public static TTransport BorrowInstance(string serviceName)
 2         {
 3             var transpool = (from tp in transport_pools where tp.ServiceConfig.Name.ToUpper() == serviceName.ToUpper() select tp).FirstOrDefault();
 4             if (transpool == null)
 5             {
 6                 throw new ThriftException(string.Format("There Is No Service Named \"{0}\"", serviceName));
 7             }
 8 
 9             TTransport transport;
10             lock (transpool.sync_obeject)
11             {
12                 if (transpool.TransportPool.Count() == 0)
13                 {
14                     if (transpool.ActivedTransportCount == transpool.ServiceConfig.MaxActive)
15                     {
16                         bool result = transpool.ResetEvent.WaitOne(transpool.ServiceConfig.WaitingTimeout);
17                         if (!result)
18                         {
19                             monitor.TimeoutNotify(transpool.ServiceConfig.Name, transpool.ServiceConfig.WaitingTimeout);
20                         }
21                     }
22                     else
23                     {
24                         transpool.TransportPool.Push(CreateTransport(transpool.ServiceConfig));
25                     }
26                 }
27 
28                 if (!transpool.TransportPool.TryPop(out transport))
29                 {
30                     throw new ThriftException("Connection Pool Exception");
31                 }
32 
33                 transpool.ActivedTransportCount++;
34 
35                 if (transpool.TransportPool.Count() < transpool.ServiceConfig.MinIdle && transpool.ActivedTransportCount < transpool.ServiceConfig.MaxActive)
36                 {
37                     transpool.TransportPool.Push(CreateTransport(transpool.ServiceConfig));
38                 }
39             }
40             if (!transport.IsOpen)
41             {
42                 transport.Open();
43             }
44             Monitor();
45             return transport;
46         }

        当实际激活的连接数达到服务节点配置的最大激活连接数,获取Socket连接的请求就将处于等待状态,超过等待时间设置,使用监视器方法monitor.TimeoutNotify()去通知管理者。连接池空闲的连接小于最小空闲连接数设置,每次请求连接都会建立一个新的连接放到池子里。

        归还连接:

 1         public static void ReturnInstance(string serviceName,TTransport transport)
 2         {
 3             var transpool = (from tp in transport_pools where tp.ServiceConfig.Name.ToUpper() == serviceName.ToUpper() select tp).FirstOrDefault();
 4             if (transpool == null)
 5             {
 6                 throw new ThriftException("Connection Pool Exception");
 7             }
 8             if (transpool.TransportPool.Count() == transpool.ServiceConfig.MaxIdle)
 9             {
10                 transport.Flush();
11                 if (transport.IsOpen)
12                 {
13                     transport.Close();
14                 }
15                 transport.Dispose();
16             }
17             else
18             {
19                 lock (transpool.sync_obeject)
20                 {
21                     if (transport.IsOpen)
22                     {
23                         transport.Close();
24                     }
25                     transpool.TransportPool.Push(transport);
26                     transpool.ActivedTransportCount--;
27                     transpool.ResetEvent.Set();
28                 }
29             }
30             Monitor();
31         }

        当连接池最大空闲连接达到了服务节点设置的最大空闲连接数时,归还的连接将被销毁。借出连接和归还连接两段代码里都有一个Monitor()方法,此方法监控连接池连接的使用情况:

        /// 
        /// 监控连接池状态
        /// 
        private static void Monitor()
        {
            Liststring, int, int>> tuples = new Liststring, int, int>>(transport_pools.Count);
            foreach(var transpool in transport_pools)
            {
                Tuple<string, int, int> tuple = new Tuple<string, int, int>(transpool.ServiceConfig.Name, transpool.TransportPool.Count(), transpool.ActivedTransportCount);
                tuples.Add(tuple);
            }
            monitor.Monitor(tuples);
        }

       此方法将每个服务连接池的空闲连接数、和激活的连接数传给前面提到的监视器。在连接等待超时和拿到连接池的运行参数时,最终进行什么动作还是由开发者去实现的。继承下面的接口,开发者可以自定义监视器。

 1     public interface IThriftFactoryMonitor
 2     {
 3         /// 
 4         /// 监控连接池运行状态
 5         /// 
 6         /// 元组集合,第一个元素表示服务名称、第二个元素表示空闲连接数量、第三个元素表示激活连接数量
 7         void Monitor(Liststring,int,int>> tuples);
 8 
 9         /// 
10         /// 等待连接超时
11         /// 
12         void TimeoutNotify(string serviceName,int timeOut);
13     }

       默认的监视器只是将连接池的运行状态记录到控制台:

 1     /// 
 2     /// 默认连接池状态监控类
 3     /// 
 4     public class ThriftFactoryMonitor : IThriftFactoryMonitor
 5     {
 6         public virtual void Monitor(Liststring, int, int>> tuples)
 7         {
 8             foreach (var t in tuples)
 9             {
10                 Console.WriteLine(string.Format("{0}连接池,空闲连接数量:{1},激活连接数量:{2}", t.Item1, t.Item2, t.Item3));
11             }
12         }
13 
14         public virtual void TimeoutNotify(string serviceName, int timeOut)
15         {
16             Console.WriteLine(string.Format("{0}连接池等待连接超时{1}", serviceName, timeOut));
17         }
18     }

    开发者自己实现的监视器,如何能被连接池使用,其实在一开始的连接池初始化里,还有一段使用反射来初始化开发者定义的监视器的代码。开发者只需在上一篇介绍的Thrift.config里配置MonitorType,其他的就交给框架处理:

 1         static ThriftFactory()
 2         {
 3             ......
 4             if(!string.IsNullOrWhiteSpace(ConfigHelper.ThriftConfig.MonitorType))
 5             {
 6                 monitor = Invoker.CreateInstance(Type.GetType(ConfigHelper.ThriftConfig.MonitorType)) as IThriftFactoryMonitor;
 7                 if (monitor == null)
 8                 {
 9                     throw new ThriftException(string.Format("There Is No Monitor Implement Which Type Is  \"{0}\"", ConfigHelper.ThriftConfig.MonitorType));
10                 }
11             }
12         }

   通过连接池与服务节点建立了Socket连接,下一篇将介绍客户端如何使用建立的Socket连接与服务端通信。

Thrift微服务代码下载Thrift.Utility

 

   

转载于:https://www.cnblogs.com/DKSL/p/Thrift_Utiliry2.html

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