20.3. Configuring HA with Static Failover

Overview

By default, HA with static failover uses a sequential strategy when selecting a replica service if the original service with which a client is communicating becomes unavailable, or fails. The sequential strategy selects a replica service in the same sequential order every time it is used. Selection is determined by Apache CXF’s internal service model and results in a deterministic failover pattern.

Configuring a random strategy

You can configure HA with static failover to use a random strategy instead of the sequential strategy when selecting a replica. The random strategy selects a random replica service each time a service becomes unavailable, or fails. The choice of failover target from the surviving members in a cluster is entirely random.
To configure the random strategy, add the configuration shown in Example 20.3, “Configuring a Random Strategy for Static Failover” to your client configuration file.

Example 20.3. Configuring a Random Strategy for Static Failover

<beans ...>
1    <bean id="Random" class="org.apache.cxf.clustering.RandomStrategy"/>
    
    <jaxws:client name="{http://apache.org/hello_world_soap_http}Replica3"
                  createdFromAPI="true">
        <jaxws:features>
            <clustering:failover>
2                <clustering:strategy>
                    <ref bean="Random"/>
                </clustering:strategy>
            </clustering:failover>
        </jaxws:features>
    </jaxws:client>
</beans>
The configuration shown in Example 20.3, “Configuring a Random Strategy for Static Failover” can be explained as follows:
1
Defines a Random bean and implementation class that implements the random strategy.
2
Specifies that the random strategy is used when selecting a replica.