6.6.5. Connector Keepalive
Version Support: 2.0.2 and later
Connections to MySQL servers can automatically time-out according to the
configured within the MySQL server.
To prevent these connections being automatically closed, the connector
can be configured to keep the connection alive by submitting a simple
SELECT statement (actually
SELECT 'KEEP_ALIVE') periodically
to ensure that the MySQL timeout is not reached and the connection
Two parameters configure the keepalive functionality:
The interval used to check for idle connections. If set to a value
of 0, the keep alive check is disabled. Any value greater than zero
is the interval check period in seconds.
The keep-alive statement is submitted if the time since the last
activity reaches this timeout value.
The default setting for both parameters is 0 (disabled).
When set to
default, the values are automatically calculated by the connector
computing suitable values based on the
configured in the MySQL server.
connection.keepAlive.interval = (int) Math.floor(wait_timeout * 0.10);
connection.keepAlive.timeout = (int) Math.floor(wait_timeout * 0.7);
These calculations cannot be modified, but the properties can be
explicitly set by using the
to explicitly set the property through tpm, for
tpm update alpha --property=connection.keepAlive.interval=30