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A library containing the JQM engine. Cannot be used alone.
/**
* Copyright © 2013 enioka. All rights reserved
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* 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 com.enioka.jqm.tools;
import java.util.Calendar;
import java.util.concurrent.Semaphore;
import java.util.concurrent.TimeUnit;
import javax.naming.spi.NamingManager;
import javax.persistence.EntityManager;
import org.apache.log4j.Logger;
import com.enioka.jqm.jpamodel.Node;
/**
* The internal poller is responsible for doing all the repetitive tasks of an engine (excluding polling queues). Namely: check if
* {@link Node#isStop()} has become true (stop order) and update {@link Node#setLastSeenAlive(java.util.Calendar)} to make visible to the
* whole cluster that the engine is still alive and that no other engine should start with the same node name.
*/
class InternalPoller implements Runnable
{
private static Logger jqmlogger = Logger.getLogger(InternalPoller.class);
private boolean run = true;
private JqmEngine engine = null;
private Thread localThread = null;
private long step;
private Node node = null;
private String logLevel = null;
private Semaphore loop = new Semaphore(0);
InternalPoller(JqmEngine e)
{
this.engine = e;
EntityManager em = Helpers.getNewEm();
// Get configuration data
node = em.find(Node.class, this.engine.getNode().getId());
this.step = Long.parseLong(Helpers.getParameter("internalPollingPeriodMs", "60000", em));
this.logLevel = node.getRootLogLevel();
em.close();
}
void stop()
{
// The test is important: it prevents the engine from calling interrupt() when stopping
// ... which can be triggered inside InternalPoller.run!
jqmlogger.info("Internal poller has received a stop request");
if (this.run)
{
this.run = false;
if (this.localThread != null)
{
this.localThread.interrupt();
}
}
}
void forceLoop()
{
this.loop.release(1);
}
@Override
public void run()
{
Thread.currentThread().setName("INTERNAL_POLLER;polling orders;");
jqmlogger.info("Start of the internal poller");
EntityManager em = null;
this.localThread = Thread.currentThread();
Calendar latestJettyRestart = Calendar.getInstance(), lastJndiPurge = latestJettyRestart;
String nodePrms = null;
// Launch main loop
while (true)
{
try
{
loop.tryAcquire(this.step, TimeUnit.MILLISECONDS);
}
catch (InterruptedException e)
{
run = false;
}
if (!run)
{
break;
}
try
{
// Get session
em = Helpers.getNewEm();
// Check if stop order
node = em.find(Node.class, node.getId());
if (node.isStop())
{
jqmlogger.info("Node has received a stop order from the database");
jqmlogger.trace("At stop order time, there are " + this.engine.getCurrentlyRunningJobCount()
+ " jobs running in the node");
this.run = false;
this.engine.stop();
em.close();
break;
}
// Change log level?
if (!this.logLevel.equals(node.getRootLogLevel()))
{
this.logLevel = node.getRootLogLevel();
Helpers.setLogLevel(this.logLevel);
}
// I am alive
em.getTransaction().begin();
em.createQuery("UPDATE Node n SET n.lastSeenAlive = current_timestamp() WHERE n.id = :id").setParameter("id", node.getId())
.executeUpdate();
em.getTransaction().commit();
// Have queue bindings changed, or is engine disabled?
this.engine.syncPollers(em, node);
// Jetty restart. Conditions are:
// * some parameters (such as security parameters) have changed
// * node parameter change such as start or stop an API.
Calendar bflkpm = Calendar.getInstance();
String np = node.getDns() + node.getPort() + node.getLoadApiAdmin() + node.getLoadApiClient() + node.getLoapApiSimple();
if (nodePrms == null)
{
nodePrms = np;
}
Long i = em
.createQuery(
"SELECT COUNT(gp) from GlobalParameter gp WHERE gp.lastModified > :lm "
+ "AND key IN ('disableWsApi', 'enableWsApiSsl', 'enableInternalPki', "
+ "'pfxPassword', 'enableWsApiAuth')", Long.class).setParameter("lm", latestJettyRestart)
.getSingleResult();
if (i > 0L || !np.equals(nodePrms))
{
this.engine.getJetty().start(node, em);
latestJettyRestart = bflkpm;
nodePrms = np;
}
// Should JNDI cache be purged?
i = em.createQuery(
"SELECT COUNT(p) FROM JndiObjectResourceParameter p WHERE p.lastModified > :lm OR p.resource.lastModified > :lm",
Long.class).setParameter("lm", lastJndiPurge).getSingleResult();
if (i > 0L)
{
try
{
((JndiContext) NamingManager.getInitialContext(null)).resetSingletons();
lastJndiPurge = bflkpm;
}
catch (Exception e)
{
jqmlogger
.warn("Could not reset JNDI singleton resources. New parameters won't be used. Restart engine to update them.",
e);
}
}
}
catch (RuntimeException e)
{
if (Helpers.testDbFailure(e))
{
jqmlogger.error("connection to database lost - stopping internal poller");
jqmlogger.trace("connection error was:", e.getCause());
run = false;
this.engine.startDbRestarter();
break;
}
else
{
throw e;
}
}
finally
{
// Loop is done, let session go
Helpers.closeQuietly(em);
}
}
jqmlogger.info("End of the internal poller");
}
}