✅ RECOMMENDED
BRIDGE MODE - ❌ NOT RECOMMENDED
When the Connector is in Bridge mode, using the native test
check will generate errors in the Tungsten Connector
logs (as well as in the MySQL error log with MySQL versions 8+).
PROXY MODE - ✅ RECOMMENDED, with Limitations
When the Connector is in Proxy mode, it will be considered as up as long as it is running, even if no database backend is available. This has a very low impact on the cluster as the connection will only affect the connector, but it does not guarantee the application will get a proper connection to the database due to the TCP-only nature of the test.
Here is a practical example for deploying the HAProxy's native TCP-based
check option.
#---------------------------------------------------------------------
# backend
#---------------------------------------------------------------------
listen connector
bind *:3306
mode tcp
option tcpka # enables keep-alive both on client and server side
balance roundrobin
server conn1 db1:3306 check inter 5s rise 1 fall 1 weight 3 maxconn 5000
server conn2 db2:3306 check inter 5s rise 1 fall 1 weight 3 maxconn 5000
server conn3 db3:3306 check inter 5s rise 1 fall 1 weight 3 maxconn 5000This solution does NOT require adding a user to MySQL.