If clients encounter Too many connections
errors when attempting to connect to the
mysqld server, all available connections
are in use by other clients.
The permitted number of connections is controlled by the
max_connections
system
variable. To support more connections, set
max_connections
to a larger
value.
mysqld actually permits
max_connections
+ 1 client connections. The extra connection is reserved for
use by accounts that have the
CONNECTION_ADMIN
privilege (or
the deprecated SUPER
privilege). By granting the privilege to administrators and
not to normal users (who should not need it), an administrator
can connect to the server and use SHOW
PROCESSLIST
to diagnose problems even if the maximum
number of unprivileged clients are connected. See
Section 15.7.7.29, “SHOW PROCESSLIST Statement”.
The server also permits administrative connections on a dedicated interface. For more information about how the server handles client connections, see Section 7.1.12.1, “Connection Interfaces”.