/**
* Configure and start the load balancer
*
* @throws LoadBalancerExtensionException if configuration or start process fails
*/
private void configureAndStart() throws LoadBalancerExtensionException {
// Initialize topology
if (!topologyEventReceiver.isInitialized()) {
topologyEventReceiver.initializeTopology();
}
// Configure load balancer
Topology topology = topologyProvider.getTopology();
if (topologyPopulated(topology) && loadBalancer.configure(topology)) {
// Start load balancer
loadBalancer.start();
loadBalancerStarted = true;
}
}
/**
* Start topology event receiver thread.
*
* @param executorService executor service instance
* @param topologyProvider topology provider instance
*/
private void startTopologyEventReceiver(
ExecutorService executorService, TopologyProvider topologyProvider) {
// Enforcing the listener order in order execute extension listener later
topologyEventReceiver = new LoadBalancerCommonTopologyEventReceiver(topologyProvider, false);
// Add load-balancer extension event listener
addTopologyEventListeners(topologyEventReceiver);
// Add default topology provider event listeners
topologyEventReceiver.addEventListeners();
topologyEventReceiver.setExecutorService(executorService);
topologyEventReceiver.execute();
if (log.isInfoEnabled()) {
log.info("Topology receiver thread started");
}
if (log.isInfoEnabled()) {
if (TopologyServiceFilter.getInstance().isActive()) {
log.info(
String.format(
"Service filter activated: [filter] %s",
TopologyServiceFilter.getInstance().toString()));
}
if (TopologyClusterFilter.getInstance().isActive()) {
log.info(
String.format(
"Cluster filter activated: [filter] %s",
TopologyClusterFilter.getInstance().toString()));
}
if (TopologyMemberFilter.getInstance().isActive()) {
log.info(
String.format(
"Member filter activated: [filter] %s",
TopologyMemberFilter.getInstance().toString()));
}
}
}
/** Stop load balancer instance. */
public void stop() {
try {
if (topologyEventReceiver != null) {
topologyEventReceiver.terminate();
}
} catch (Exception ignore) {
}
try {
if (statisticsNotifier != null) {
statisticsNotifier.terminate();
}
} catch (Exception ignore) {
}
try {
loadBalancer.stop();
} catch (Exception ignore) {
}
}
/**
* Add topology event listeners to the topology event receiver.
*
* @param topologyEventReceiver topology event receiver instance
*/
private void addTopologyEventListeners(
final LoadBalancerCommonTopologyEventReceiver topologyEventReceiver) {
topologyEventReceiver.addEventListener(
new CompleteTopologyEventListener() {
@Override
protected void onEvent(Event event) {
try {
if (!loadBalancerStarted) {
configureAndStart();
}
} catch (Exception e) {
if (log.isErrorEnabled()) {
log.error("Could not start load balancer", e);
}
stop();
}
}
});
topologyEventReceiver.addEventListener(
new MemberActivatedEventListener() {
@Override
protected void onEvent(Event event) {
reloadConfiguration();
}
});
topologyEventReceiver.addEventListener(
new MemberSuspendedEventListener() {
@Override
protected void onEvent(Event event) {
reloadConfiguration();
}
});
topologyEventReceiver.addEventListener(
new MemberTerminatedEventListener() {
@Override
protected void onEvent(Event event) {
reloadConfiguration();
}
});
topologyEventReceiver.addEventListener(
new ClusterRemovedEventListener() {
@Override
protected void onEvent(Event event) {
reloadConfiguration();
}
});
topologyEventReceiver.addEventListener(
new ServiceRemovedEventListener() {
@Override
protected void onEvent(Event event) {
reloadConfiguration();
}
});
topologyEventReceiver.addEventListener(
new MemberMaintenanceListener() {
@Override
protected void onEvent(Event event) {
reloadConfiguration();
}
});
}
