21.8.7.50 mysql_ping()

int mysql_ping(MYSQL *mysql)

Description

Checks whether the connection to the server is working. If the connection has gone down and auto-reconnect is enabled an attempt to reconnect is made. If the connection is down and auto-reconnect is disabled, mysql_ping() returns an error.

Auto-reconnect is disabled by default. To enable it, call mysql_options() with the MYSQL_OPT_RECONNECT option. For details, see Section 21.8.7.49, “mysql_options().

mysql_ping() 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.

If mysql_ping()) does cause a reconnect, there is no explicit indication of it. To determine whether a reconnect occurs, call mysql_thread_id() to get the original connection identifier before calling mysql_ping(), then call mysql_thread_id() again to see whether the identifier has changed.

If reconnect occurs, some characteristics of the connection will have been reset. For details about these characteristics, see Section 21.8.15, “Controlling Automatic Reconnection Behavior”.

Return Values

Zero if the connection to the server is active. Nonzero if an error occurred. A nonzero return does not indicate whether the MySQL server itself is down; the connection might be broken for other reasons such as network problems.

Errors