go语言作为客户端，使用ssh同时连接700多个服务器，运行一段时候为什么会报错：because the target machine actively refused it.？

Question

代码框架为：

func NewSSHClient(ip string, port int, user, passwd string) (*SSHClient, error) {
    config := &ssh.ClientConfig{
        User: user,
        Auth: []ssh.AuthMethod{
            ssh.Password(passwd),
        },
        HostKeyCallback: ssh.InsecureIgnoreHostKey(),
        Timeout:         30 * time.Second,
    }

    sshConn, err := ssh.Dial("tcp", fmt.Sprintf("%s:%d", ip, port), config)
    if err != nil {
        return nil, err
    }

    sftpClient, err := sftp.NewClient(sshConn)
    if err != nil {
        return nil, err
    }

    return &SSHClient{
        Ip:     ip,
        port:   port,
        user:   user,
        passwd: passwd,
        ssh:    sshConn,
        sftp:   sftpClient,
    }, nil
}

func main() {

    // errors := make(chan error)
    limits := make(chan struct{}, 256)

    var wg sync.WaitGroup
    for host := range hosts {
        wg.Add(1)
        go func(host string) {
            defer wg.Done()
            defer func(limits *chan struct{}) { <-*limits }(&limits)
            limits <- struct{}{}
            for {

                for _, ng := range nginxHost {
                    a, err := NewSSHClient(hosts[host], host)
                    if err != nil {
                            log.Errorf("%s NewMonitor fail err:%s", host, err)
                            time.Sleep(30 * time.Second)
                            continue
                    }
                    a.dosomething()
                }
                
                time.Sleep(30 * time.Second)
            }
        }(host)
    }
    wg.Wait()
}

出错还是比较有规律，比如某个服务器前面三次连接正常，第四次开始及以后都会一直报错No connection could be made because the target machine actively refused it.

Answer 1

看看这篇文章：https://dailydevsblog.com/troubleshoot/resolved-no-connection...