Strictly speaking, it is not wM that manages that. It is the JDBC driver, provided by IBM. It is the driver that performs load balancing and failover facilities, not wM IS. (And I’m not sure that load balancing is provided, though it may be.)
The following link may be helpful.
The “DB2 Universal JDBC Driver behavior when running DB2 HADR” section describes how the JDBC driver behaves for failover.
The “Configuring WebSphere Application Server” section notes “[the DB2 client] doesn’t need to know anything about the standby machine, since the high availability and client reroute features are supported on the DB2 server side. Hence, you will define your DB2 datasource in the same manner as if you were not using HADR.” While the screenshot is of WAS, the configuration items are always the same for the driver. What differs is how the system that is hosting the driver captures the configuration settings from the user.
For the additional properties described in that section, you can apply those in the Other Properties field when configuring the connection.
Hope this helps. Or at least leads you to the info you need.