go - 如何处理服务器上客户端的断开连接

Question

我正在使用gRPC构建监视系统。为此，我需要知道gRPC客户端是否崩溃并因此与gRPC服务器断开连接。
这就是我创建服务器的方式。

var kaep = keepalive.EnforcementPolicy{
    MinTime:             5 * time.Second, // If a client pings more than once every 5 seconds, terminate the connection
    PermitWithoutStream: true,            // Allow pings even when there are no active streams
}

var kasp = keepalive.ServerParameters{
    MaxConnectionIdle:     15 * time.Second, // If a client is idle for 15 seconds, send a GOAWAY
    MaxConnectionAgeGrace: 5 * time.Second,  // Allow 5 seconds for pending RPCs to complete before forcibly closing connections
    Time:                  5 * time.Second,  // Ping the client if it is idle for 5 seconds to ensure the connection is still active
    Timeout:               1 * time.Second,  // Wait 1 second for the ping ack before assuming the connection is dead
}

    s := grpc.NewServer(grpc.KeepaliveEnforcementPolicy(kaep), grpc.KeepaliveParams(kasp))
    pb.RegisterHeartbeatGRPCServer(s, bt)
    if err := s.Serve(lis); err != nil {
        log.Fatalf("failed to serve: %v", err)
    }

我发现，保持 Activity 的概念可能对检测断开连接的客户端很有用。
https://github.com/grpc/grpc-go/blob/master/Documentation/keepalive.md
但是，我不确定如何处理断开连接。
如何处理这种断开？更确切地说，我想在客户端断开连接时调用ClientDisconnected(clientId)函数。那可能吗？

Answer 1

您可能要为此使用统计处理程序。特别是，您在寻找ConnEnd操作:
https://godoc.org/google.golang.org/grpc/stats#ConnEnd
https://godoc.org/google.golang.org/grpc/stats#Handler(您正在寻找TagConn和HandleConn)
https://godoc.org/google.golang.org/grpc#StatsHandler