This does not work with mysqlnd and is marked as wontfix: https://bugs.php.net/bug.php?id=52561
(PHP 5, PHP 7, PHP 8)
mysqli::ping -- mysqli_ping — Pings a server connection, or tries to reconnect if the connection has gone down
This function has been DEPRECATED as of PHP 8.4.0. Relying on this function is highly discouraged.
Object-oriented style
Procedural style
Checks whether the connection to the server is working. If it has gone down and global option mysqli.reconnect is enabled, an automatic reconnection is attempted.
Note: The php.ini setting mysqli.reconnect is ignored by the mysqlnd driver, so automatic reconnection is never attempted.
This function can be used by clients that remain idle for a long while, to check whether the server has closed the connection and reconnect if necessary.
mysqlProcedural style only: A mysqli object returned by mysqli_connect() or mysqli_init()
If mysqli error reporting is enabled (MYSQLI_REPORT_ERROR) and the requested operation fails,
a warning is generated. If, in addition, the mode is set to MYSQLI_REPORT_STRICT,
a mysqli_sql_exception is thrown instead.
| Version | Description |
|---|---|
| 8.4.0 |
Both mysqli::ping() and
mysqli_ping() are now deprecated.
The reconnect feature has not been available
as of PHP 8.2.0, making this function obsolete.
|
Example #1 mysqli::ping() example
Object-oriented style
<?php
$mysqli = new mysqli("localhost", "my_user", "my_password", "world");
/* check connection */
if ($mysqli->connect_errno) {
printf("Connect failed: %s\n", $mysqli->connect_error);
exit();
}
/* check if server is alive */
if ($mysqli->ping()) {
printf ("Our connection is ok!\n");
} else {
printf ("Error: %s\n", $mysqli->error);
}
/* close connection */
$mysqli->close();
?>Procedural style
<?php
$link = mysqli_connect("localhost", "my_user", "my_password", "world");
/* check connection */
if (mysqli_connect_errno()) {
printf("Connect failed: %s\n", mysqli_connect_error());
exit();
}
/* check if server is alive */
if (mysqli_ping($link)) {
printf ("Our connection is ok!\n");
} else {
printf ("Error: %s\n", mysqli_error($link));
}
/* close connection */
mysqli_close($link);
?>The above examples will output:
Our connection is ok!
This does not work with mysqlnd and is marked as wontfix: https://bugs.php.net/bug.php?id=52561As jay at grooveshark dot com very helpfully pointed out, the mysqlnd driver which is becoming pretty standard does not obey reconnect commands. If you have a DB wrapper class (which hopefully you do) you can implement your own version of ping() such as:<?phpclass db extends mysqli{ private $db_host; private $db_user; private $db_pass; private $db_name; private $persistent; public function __construct($db_host, $db_user, $db_pass, $db_name, $persistent = true) { $this->db_host = $db_host; $this->db_user = $db_user; $this->db_pass = $db_pass; $this->db_name = $db_name; $this->persistent = $persistent; parent::init(); parent::options(MYSQLI_OPT_CONNECT_TIMEOUT, 1); @parent::real_connect(($this->persistent ? 'p:' : '') . $this->db_host, $this->db_user, $this->db_pass, $this->db_name); if ($this->connect_errno) die("All DB servers down!\n"); } public function ping() { @parent::query('SELECT LAST_INSERT_ID()'); if ($this->errno == 2006) $this->__construct($this->db_host, $this->db_user, $this->db_pass, $this->db_name, $this->persistent); }...}$db = new db(DB_HOST, DB_USER, DB_PASS, DB_NAME);// Some code that potentially takes a really long time to execute goes here// Ping for safety to try to gracefully reconnect$db->ping();// Now we should be able to run queries again$db->query('SELECT LAST_INSERT_ID()');?>If you wanted you could even put "$this->ping();" at the top of db::query() to avoid any explicit reconnection calls but I wouldn't recommend it due to the (slight) overhead of running the cheap "SELECT LAST_INSERT_ID()" query every time prior to running your real intended query. There are probably even cheaper queries to run in favor of "SELECT LAST_INSERT_ID()" but it was the first that came to mind and is cheap enough for most purposes since you shouldn't be calling ping() a whole bunch anyway.The behaviour about the option mysqli.reconnect is default set to Off at Debian PHP Packages. So i would recommend to update the first line description about the recommendation at the option mysqli.reconnect. (practice note ;))