A tutorial to implement automatic re-interconnection of TCP

The following small series for everyone to bring a Golang TCP automatic re-connect implementation method. Small series feel very good, now share to everyone, also for everyone to make a reference. Let's take a look at it with a little knitting.

Operating system: CentOS 6.9_x64

Go language version: 1.8.3

Problem description

There is a TCP client program that needs to fetch data from the server on a regular basis, but it needs to be automatically re-connected for a variety of reasons (network instability, etc.).

Test Server Sample code:

/*tcp Server for Test*/package mainimport ("FMT" "NET" "OS" "Strings" "Time") Func CheckError (err error) {if err! = Nil {fmt. PRINTLN (ERR) OS. Exit (1)}}func handleclient (conn net. Conn) {Conn. Setreaddeadline (time. Now (). ADD (3 * time. Minute) Request: = Make ([]byte,1024) defer Conn. Close () for {recv_len,err: = conn. Read (Request) if err! = Nil {fmt. Println (ERR) Break} if Recv_len = = 0 {break} recvdata: = Strings. Trimspace (String (Request[:recv_len)) fmt. Println ("Recv_len:", Recv_len) fmt. Println ("Recv_data:" + recvdata) Daytime: = time. Now (). String () Conn. Write ([]byte (daytime + "\ n")) request = make ([]byte,1024)}}func main () {bindinfo: = ": 12345" tcpaddr,err: = Net. RESOLVETCPADDR ("TCP4", Bindinfo) checkerror (err) Listener,err: = Net. LISTENTCP ("TCP", TCPADDR) CheckError (err) for {cc,err: = listener. Accept () if err! = nil {Continue} go Handleclient (cc)}}

Solution Solutions

/*TCP Client with Reconnect*/package mainimport (  "NET"  "FMT"  "Bufio" "Time  ") func dotask (conn net. Conn) {for  {    FMT. fprintf (conn, "Test msg\n")    msg,err: = Bufio. Newreader (conn). ReadString (' \ n ')    if err! = Nil {      FMT. Println ("recv data Error")      break    }else{      FMT. Println ("recv msg:", msg)    } time    . Sleep (1 * time. Second)  }}func Main () {  Hostinfo: = "127.0.0.1:12345" for  {    Conn,err: = Net. Dial ("TCP", Hostinfo)    FMT. Print ("Connect (", hostinfo)    if err! = Nil {      FMT. Println (") fail")    }else{      FMT. Println (") OK")      defer Conn. Close ()      dotask (conn)    } time    . Sleep (3 * time. Second)  }}

Operating effect:

[Root@local t1]#/tcpclient1connect (127.0.0.1:12345) okrecv msg:2017-06-12 21:10:32.110977137 +0800 CSTrecv msg:2017 -06-12 21:10:33.111868746 +0800 cstrecv data errorconnect (127.0.0.1:12345) failconnect (127.0.0.1:12345) Failconnect ( 127.0.0.1:12345) okrecv msg:2017-06-12 21:10:43.117203432 +0800 cstrecv msg:2017-06-12 21:10:44.11853427 +0800 CST

Discuss

Here is a simple example code that implements TCP auto-re-interconnection.

All right, that's it, I hope it helps you.