php 使用pdo连接数据库出现大量time_wait

无预连接


function db_con_basic(){
        $dsn  = 'mysql:dbname=test;host=127.0.0.1';
        $user = 'test';
        $pwd  = 'test';

        try {
                $dbh  = new PDO($dsn, $user, $pwd);
                $dbh -> query('use test;');
        } catch (Exception $e) {
                print "Error!: " . $e->getMessage() ;
        die();
        }
        return $dbh;
}

 

while(1){
                $pdo=db_con_basic();          
                $cxArr=$pdo->query("select * from test")->fetchAll(PDO::FETCH_ASSOC);
                $pdo=null;
    
}


?>

大量time_wait

有预连接，无time_wait


function db_con_basic(){
        $dsn  = 'mysql:dbname=test;host=127.0.0.1';
        $user = 'test';
        $pwd  = 'test';

        try {
                $dbh  = new PDO($dsn, $user, $pwd);
                $dbh -> query('use test;');
        } catch (Exception $e) {
                print "Error!: " . $e->getMessage() ;
        die();
        }
        return $dbh;
}

                $pdo=db_con_basic();  
          
while(1){
                        
                $cxArr=$pdo->query("select * from test")->fetchAll(PDO::FETCH_ASSOC);    
}
                $pdo=null;

?>