You may choose to use an external tcp load balancer, such as haproxy. The Teiid driver/DataSource should then typically be configured to just use the single host/port of your load balancer. The load balancer should use an algorithm that supports sticky connections as Teiid sessions as specific to the original host. For HAProxy it is recommended that you use leastconn or source.

Even if you configure the load balancer to redirect when there is a failed host, that will not maintain the Teiid session state. If you wish to keep the connection alive, then use the autoFailover feature discussed below. Otherwise the other Teiid Client Features are not necessary when using an external load balancer.

To enable theses features in their simplest form, the client needs to specify multiple host name and port number combinations on the URL connection string.

If you are using a DataSource to connect to Teiid Server, use the "AlternateServers" property/method to define the failover servers. The format is also a comma separated list of host:port combinations.

The client will randomly pick one the Teiid server from the list and establish a session with that server. If that server cannot be contacted, then a connection will be attempted to each of the remaining servers in random order. This allows for both connection time fail-over and random server selection load balancing.