/*
* Copyright 2016 Red Hat, Inc. and/or its affiliates.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.kie.server.services.impl.policy;
import java.util.ArrayList;
import java.util.Date;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.ServiceLoader;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.ScheduledFuture;
import java.util.concurrent.TimeUnit;
import javax.naming.InitialContext;
import org.kie.server.api.KieServerConstants;
import org.kie.server.services.api.KieServer;
import org.kie.server.services.api.KieServerRegistry;
import org.kie.server.services.api.Policy;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Responsible for complete life cycle of the policies and their execution.
*/
public class PolicyManager {
private static final Logger logger = LoggerFactory.getLogger(PolicyManager.class);
private static final ServiceLoader<Policy> policyServiceLoader = ServiceLoader.load(Policy.class);
private Map<String, Policy> registeredPolicies = new HashMap<>();
private Map<String, ScheduledFuture<?>> activatedPolicies = new HashMap<>();
private KieServer kieServer;
private KieServerRegistry kieServerRegistry;
private boolean managedExecutorService = false;
private ScheduledExecutorService scheduledExecutorService = getScheduledExecutorService();
public synchronized void start(KieServer kieServer, KieServerRegistry kieServerRegistry) {
this.kieServer = kieServer;
this.kieServerRegistry = kieServerRegistry;
logger.debug("Starting policy manager...");
policyServiceLoader.forEach( p -> {
registeredPolicies.put(p.getName(), p);
logger.info("Registered {} policy under name {}", p, p.getName());
});
String toActivate = System.getProperty(KieServerConstants.KIE_SERVER_ACTIVATE_POLICIES);
if (toActivate != null) {
String[] policies = toActivate.split(",");
logger.debug("Following policies will be activated {}", policies);
for (String policy : policies) {
String policyName = policy.trim();
activatePolicy(policyName);
}
}
logger.info("Policy manager started successfully, activated policies are {}", activatedPolicies.keySet());
}
public synchronized void stop() {
logger.debug("Stopping policy manager...");
if (!managedExecutorService) {
scheduledExecutorService.shutdownNow();
logger.debug("Not managed executor service stopped");
}
List<String> activePolicies = new ArrayList<>(activatedPolicies.keySet());
activePolicies.forEach(policyName -> {
deactivatePolicy(policyName);
});
activatedPolicies.clear();
logger.info("Policy manager stopped successfully");
}
public void activatePolicy(String policyName) {
Policy policyInstance = registeredPolicies.get(policyName);
if (policyInstance == null) {
logger.warn("Policy '{}' requested to be activated but was not registered, known policies are {}", policyName, registeredPolicies.keySet());
return;
}
try {
logger.debug("Starting policy {}", policyInstance);
policyInstance.start();
logger.debug("Policy {} successfully started", policyInstance);
long interval = policyInstance.getInterval();
if (interval <= 0) {
logger.error("Policy {} returned invalid (must be bigger than 0) interval {}, won't be activated", policyInstance, interval);
return;
}
ScheduledFuture<?> future = scheduledExecutorService.scheduleAtFixedRate(() -> {
logger.debug("About to apply policy {} at {}", policyInstance, new Date());
try {
policyInstance.apply(this.kieServerRegistry, this.kieServer);
logger.debug("Policy {} applied successfully at {}", policyInstance, new Date());
} catch (Throwable e) {
logger.error("Policy {} failed to be applied due to {}", policyInstance, e.getMessage(), e);
}
},
interval,
interval,
TimeUnit.MILLISECONDS);
logger.debug("Policy {} successfully activated, will be applied at {}", policyInstance, new Date(System.currentTimeMillis() + future.getDelay(TimeUnit.MILLISECONDS)));
activatedPolicies.put(policyName, future);
} catch (Exception e) {
logger.error("Failed during activation of policy {} due to {}", policyInstance, e.getMessage(), e);
}
}
public void deactivatePolicy(String policyName) {
Policy policy = registeredPolicies.get(policyName);
ScheduledFuture<?> future = activatedPolicies.remove(policyName);
future.cancel(true);
logger.debug("Policy {} deactivated successfully", policy);
policy.stop();
logger.debug("Policy {} stopped successfully", policy);
}
protected ScheduledExecutorService getScheduledExecutorService() {
ScheduledExecutorService executorService = null;
try {
executorService = InitialContext.doLookup("java:comp/DefaultManagedScheduledExecutorService");
logger.debug("JEE version of scheduled executor service found");
managedExecutorService = true;
} catch (Exception e) {
executorService = Executors.newSingleThreadScheduledExecutor();
logger.debug("Cannot find managed scheduled executor service using standard one instead", e);
managedExecutorService = false;
}
logger.debug("Executor service to be used is {}", executorService);
return executorService;
}
}