PHP socket_read error reporting problem

centos7,php5.6 environment
now encounters such a problem. In the same class, there are three methods that use the following code (the values of $host and $port are fixed).
an error is reported when executing to the socket_read () of the second method. The error message is as follows.
socket_read (): unable to read from socket [104]: Connection reset by peer in

$socket = $this->getSocket($host,$port);
        if(!$socket){
            echo "socket";
            return;
        }
        $res1 = socket_write($socket, $this->login, strlen($this->login));
        //$str.
        $res2 = socket_write($socket, $str, strlen($str));
        if(!$res1 || !$res2){
            echo "";
            return;
        }
                while (true) {
   //socket_readsocket_read(): unable to read from socket [104]: Connection reset by peer in xxx
            $response = socket_read($socket, 1024);
        
            }

here is the code for the getSocket () method

public function getSocket($host,$port)
    {
    //static::$mySocket = null;
        if(!self::$mySocket){
            self::$mySocket = socket_create(AF_INET, SOCK_STREAM, SOL_TCP);
            if(!self::$mySocket){
                return false;
            }
            socket_set_option(self::$mySocket,SOL_SOCKET,SO_RCVTIMEO,array("sec"=>1, "usec"=>0 ) );
            socket_set_option(self::$mySocket,SOL_SOCKET,SO_SNDTIMEO,array("sec"=>1, "usec"=>0 ) );
            $result = socket_connect(self::$mySocket, $host,$port);
            if (!$result) {
            self::$mySocket = null;
                return false;
            }
        }
        return self::$mySocket;
    }

but when I change the getSocket method to the following, I won"t report an error.
is it because you need to re-execute socket_create and socket_connect before each socket_write?
Please take a look, thank you very much!

 public function getSocket($host,$port)
    {
        $socket = socket_create(AF_INET, SOCK_STREAM, SOL_TCP);
        if(!$socket){
            return false;
        }
        socket_set_option($socket,SOL_SOCKET,SO_RCVTIMEO,array("sec"=>1, "usec"=>0 ) );
        socket_set_option($socket,SOL_SOCKET,SO_SNDTIMEO,array("sec"=>1, "usec"=>0 ) );
        $result = socket_connect($socket, $host,$port);
        if (!$result) {
            return false;
        }else{
            return $socket;
        }
    }
Dec.18,2021
MySQL Query : SELECT * FROM `codeshelper`.`v9_news` WHERE status=99 AND catid='6' ORDER BY rand() LIMIT 5
MySQL Error : Disk full (/tmp/#sql-temptable-64f5-7b7015-88c7.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
MySQL Errno : 1021
Message : Disk full (/tmp/#sql-temptable-64f5-7b7015-88c7.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
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