package org.playorm.cron.impl;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import javax.inject.Inject;
import org.joda.time.DateTime;
import org.playorm.cron.api.CronListener;
import org.playorm.cron.api.PlayOrmCronJob;
import org.playorm.cron.impl.db.MonitorDbo;
import org.playorm.cron.impl.db.WebNodeDbo;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.alvazan.orm.api.base.NoSqlEntityManager;
import com.alvazan.orm.api.base.NoSqlEntityManagerFactory;
import com.alvazan.orm.api.z8spi.KeyValue;
import com.alvazan.orm.api.z8spi.iter.Cursor;
public class CheckClusterRunnable implements Runnable {
private static final Logger log = LoggerFactory.getLogger(CheckClusterRunnable.class);
@Inject
private Config config;
@Inject
private HashGenerator hashGen;
@Inject
private CurrentTime time;
private NoSqlEntityManagerFactory factory;
private CronListener listener;
@Override
public void run() {
try {
if(log.isDebugEnabled())
log.debug("firing cluster runnable");
runImpl();
} catch(Exception e) {
if (log.isWarnEnabled())
log.warn("Exception", e);
}
}
public void runImpl() {
if(listener == null)
return; //no need to do anything
NoSqlEntityManager mgr = factory.createEntityManager();
Cursor<KeyValue<WebNodeDbo>> cursor = WebNodeDbo.findAllNodes(mgr);
List<WebNodeDbo> all = new ArrayList<WebNodeDbo>();
List<WebNodeDbo> servers = new ArrayList<WebNodeDbo>();
while(cursor.next()) {
KeyValue<WebNodeDbo> kv = cursor.getCurrent();
WebNodeDbo val = kv.getValue();
all.add(val);
if(log.isDebugEnabled())
log.debug("checking node="+val.getWebServerName());
if(isServerUp(mgr, val)) {
if(log.isDebugEnabled())
log.debug("server is up="+val.getWebServerName());
servers.add(val);
}
if(val.getWebServerName().equals(config.getHostName())) {
if(log.isDebugEnabled())
log.debug("saving our node to be up="+val.getWebServerName());
saveNodeIsUp(mgr, val);
}
}
mgr.clear();
Collections.sort(servers, new ServerComparator());
int serverNumber = -1;
for(int i = 0; i < servers.size(); i++) {
WebNodeDbo node = servers.get(i);
if(node.getWebServerName().equals(config.getHostName())) {
if(log.isDebugEnabled())
log.debug("we are server number="+i+" out of number="+servers.size());
serverNumber = i;
break;
}
}
if(serverNumber == -1)
throw new IllegalStateException("serverNumber not found in list of servers="+all);
runOurMonitors(mgr, servers.size(), serverNumber);
}
private void saveNodeIsUp(NoSqlEntityManager mgr, WebNodeDbo val) {
val.setLastSeen(new DateTime());
val.setUp(true);
mgr.put(val);
mgr.flush();
}
private void runOurMonitors(NoSqlEntityManager mgr, int numUpWebNodes, int serverNumber) {
if (log.isInfoEnabled())
log.info("num up nodes="+numUpWebNodes+" servernum="+serverNumber);
Cursor<KeyValue<MonitorDbo>> cursor = MonitorDbo.findAll(mgr);
while(cursor.next()) {
KeyValue<MonitorDbo> kv = cursor.getCurrent();
MonitorDbo val = kv.getValue();
String id = val.getId();
int hash = id.hashCode();
int serverNum = hashGen.generate(hash, numUpWebNodes);
if (log.isInfoEnabled())
log.info("monitor="+val.getId()+" target server num="+serverNum+" our servernum="+serverNumber);
if(serverNum == serverNumber)
processMonitor(mgr, val);
}
}
private void processMonitor(NoSqlEntityManager mgr, MonitorDbo monitor) {
DateTime now = time.currentTime();
boolean shouldRun = calculateShouldRun(mgr, monitor, now);
if(shouldRun)
runMonitor(mgr, monitor, now);
}
private boolean calculateShouldRun(NoSqlEntityManager mgr, MonitorDbo monitor, DateTime now) {
DateTime lastRunTime = monitor.getLastRun();
if(log.isDebugEnabled())
log.debug("now="+now+" and lastrun time="+lastRunTime+" for monitor="+monitor.getId());
if(lastRunTime == null) {
return isInRunWindow(monitor, now);
} else if(nextRuntimeHasPassed(lastRunTime, monitor, now))
return true;
return false;
}
private boolean nextRuntimeHasPassed(DateTime lastRunTime,
MonitorDbo monitor, DateTime now) {
//subtract 1000 or 1 second in case they line up on the minute intervals so we fire every two minutes if
//they choose 2 minutes
long timePeriod = monitor.getTimePeriodMillis();
if(monitor.getEpochOffset() == null) {
DateTime nextRun = lastRunTime.plus(timePeriod-1000);
if(now.isAfter(nextRun))
return true;
return false;
}
DateTime lastShouldRun = monitor.getLastShouldHaveRun();
DateTime nextRun = lastShouldRun.plus(timePeriod);
if(now.isAfter(nextRun.minus(1000))) {
monitor.setLastShouldHaveRun(nextRun);
return true;
}
return false;
}
private boolean isInRunWindow(MonitorDbo monitor, DateTime now) {
if(monitor.getEpochOffset() == null) {
//If there is no epoch offset, we just start when the server starts
return true;
}
long half = config.getRate() / 2;
long nowMillis = now.getMillis();
long range = nowMillis - monitor.getEpochOffset();
long multiplier = range / monitor.getTimePeriodMillis();
long timePoint1 = monitor.getEpochOffset() + multiplier*monitor.getTimePeriodMillis();
long timePoint2 = timePoint1+monitor.getTimePeriodMillis();
long theTime = timePoint1;
if(Math.abs(timePoint2-nowMillis) < Math.abs(timePoint1-nowMillis))
theTime = timePoint2;
if(Math.abs(nowMillis-theTime) < half) {
DateTime t = new DateTime(theTime);
monitor.setLastShouldHaveRun(t);
return true;
}
return false;
}
private void runMonitor(NoSqlEntityManager mgr, MonitorDbo monitor,
DateTime now) {
if(log.isDebugEnabled())
log.debug("run monitor="+monitor.getId());
PlayOrmCronJob p = CopyUtil.copy(monitor);
fireToListener(p);
monitor.setLastRun(now);
mgr.put(monitor);
mgr.flush();
}
private void fireToListener(PlayOrmCronJob monitor) {
try {
listener.monitorFired(monitor);
} catch(Exception e) {
if (log.isWarnEnabled())
log.warn("Listener threw an exception, check your client code for a bug(we catch, log and continue)", e);
}
}
private boolean isServerUp(NoSqlEntityManager mgr, WebNodeDbo val) {
long rateInMillis = config.getRate();
DateTime lastSeen = val.getLastSeen();
DateTime now = new DateTime();
DateTime before = now.minus(rateInMillis);
//give it 15 seconds before it really should be up to date in the table
before = before.minusSeconds(15);
if(lastSeen.isBefore(before)) {
return false;
}
return true;
}
public void setFactory(NoSqlEntityManagerFactory factory) {
this.factory = factory;
}
public void setListener(CronListener listener) {
this.listener = listener;
}
}