Starting from CXF 2.4.1, CXF JAX-RS clients can be configured for them to become failover-capable.
Core CXF Failover and Load Distribution features are supported.

...

Circuit Breakers Failover

...

The recent addition to CXF failover features is the implementation based on circuit breakers, more precisely Apache Zest (https://zest.apache.org/) library. The configuration is very similar to the regular failover strategy, the only difference is usage of clustering:circuit-breaker-failover element.

Code Block
xml xml
<beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:jaxrs="http://cxf.apache.org/jaxrs" xmlns:clustering="http://cxf.apache.org/clustering" xmlns:util="http://www.springframework.org/schema/util" xsi:schemaLocation=" http://cxf.apache.org/jaxrs http://cxf.apache.org/schemas/jaxrs.xsd http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util.xsd"> <bean class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer"/> <util:list id="addressList"> <value>http://localhost:${testutil.ports.Server.1}/rest</value> <value>http://localhost:${testutil.ports.Server.2}/rest</value> <value>http://localhost:${testutil.ports.Server.3}/rest</value> </util:list> <bean id="SequentialAddresses" class="org.apache.cxf.clustering.SequentialStrategy"> <property name="alternateAddresses"> <ref bean="addressList"/> </property> </bean> <bean id="RandomAddresses" class="org.apache.cxf.clustering.RandomStrategy"> <property name="alternateAddresses"> <ref bean="addressList"/> </property> </bean> <jaxrs:client id="failoverSequential" address="http://localhost:8080/initialAddress"> <jaxrs:features> <clustering:circuit-breaker-failover threshold="1" timeout="60000"> <clustering:strategy> <ref bean="SequentialAddresses"/> </clustering:strategy> </clustering:circuit-breaker-failover> </jaxrs:features> </jaxrs:client> <jaxrs:client id="failoverRandom" address="http://localhost:8080/initialAddress"> <jaxrs:features> <clustering:circuit-breaker-failover threshold="1" timeout="60000"> <clustering:strategy> <ref bean="RandomAddresses"/> </clustering:strategy> </clustering:circuit-breaker-failover> </jaxrs:features> </jaxrs:client> <bean id="myWebClient" class="org.apache.cxf.jaxrs.client.JAXRSClientFactoryBean" factory-method="createWebClient"> <property name="address" value="http://some.base.url.that.responds/" /> <property name="features"> <ref bean="failover1"/> </property> </bean> </beans>

Circuit breakers have recommended themselves as a proven strategy to handle and monitor the failures related to external service calls, giving the external systems a time to recover by preventing endless retries or time-outing. For that reason, two configuration parameters could be tuned:

• threshold: the error threshold to open the circuit breaker
• timeout: the timeout to wait before trying the next invocation

Code

org.apache.cxf.jaxrs.features.clustering.CircuitBreakerFailoverFeaturefeature = 
    new org.apache.cxf.jaxrs.features.clustering.CircuitBreakerFailoverFeature(1, 60000);
List<String> alternateAddresses = new ArrayList<String>();
// addresses are alternate addresses provided at start-up
for (String s : address) {
    alternateAddresses.add(s);
}
SequentialStrategy strategy = new SequentialStrategy();
strategy.setAlternateAddresses(alternateAddresses);
feature.setStrategy(strategy);

JAXRSClientFactoryBean bean = new JAXRSClientFactoryBean();
bean.setAddress("http://localhost:8080/inactive-replica");
List<Feature> features = new ArrayList<Feature>();
features.add(feature);
bean.setFeatures(features);

// create proxy:
bean.create(BookStore.class);
// create web client
bean.createWebClient();

Load Distribution

CXF Load Distribution feature is a failover feature which can iterate where alternate addresses not only in case of failures but also after a successful invocation has been done.

...