/*
* INESC-ID, Instituto de Engenharia de Sistemas e Computadores Investigação e Desevolvimento em Lisboa
* Copyright 2013 INESC-ID and/or its affiliates and other
* contributors as indicated by the @author tags. All rights reserved.
* See the copyright.txt in the distribution for a full listing of
* individual contributors.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 3.0 of
* the License, or (at your option) any later version.
*
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
package org.infinispan.dataplacement;
import org.infinispan.remoting.transport.Address;
import org.infinispan.util.logging.Log;
import org.infinispan.util.logging.LogFactory;
/**
* Manages the round Id, blocks commands from round ahead of time and data placement request if another request is in
* progress
*
* @author Pedro Ruivo
* @since 5.2
*/
public class RoundManager {
private static final Log log = LogFactory.getLog(RoundManager.class);
private long currentRoundId;
private long nextRoundId;
private ClusterSnapshot roundClusterSnapshot;
//in milliseconds
private long coolDownTime;
//after this time, a next round can start
private long nextRoundTimestamp;
private boolean roundInProgress;
private boolean enabled = false;
public RoundManager(long coolDownTime) {
this.coolDownTime = coolDownTime;
roundInProgress = false;
updateNextRoundTimestamp();
}
/**
* enables the data placement optimization
*/
public final synchronized void enable() {
enabled = true;
}
/**
* returns the current round Id
*
* @return the current round Id
*/
public final synchronized long getCurrentRoundId() {
return currentRoundId;
}
/**
* returns a new round Id. this is invoked by the coordinator before start a new round´
*
* @return a new round Id
* @throws Exception if the last request happened recently or another request is in progress
*/
public final synchronized long getNewRoundId() throws Exception {
if (!enabled) {
log.warn("Trying to start data placement algorithm but it is not enabled");
throw new Exception("Data Placement optimization not enabled");
}
if (System.currentTimeMillis() < nextRoundTimestamp) {
log.warn("Trying to start data placement algorithm but the last round happened recently");
throw new Exception("Cannot start the next round. The last round happened recently");
}
if (roundInProgress) {
log.warn("Trying to start data placement algorithm but it is already in progress");
throw new Exception("Cannot start the next round. Another round is in progress");
}
updateNextRoundTimestamp();
return ++nextRoundId;
}
/**
* checks if the replication degree change can happen and updates the new round timestamp
*
* @throws Exception if the last request happened recently or another request is in progress
*/
public final synchronized void replicationDegreeRequest() throws Exception {
if (!enabled) {
log.warn("Trying to change the replication degree but Data Placement is not enabled");
throw new Exception("Data Placement optimization not enabled");
}
if (System.currentTimeMillis() < nextRoundTimestamp) {
log.warn("Trying to change the replication degree but the last optimization happened recently");
throw new Exception("Cannot start the next round. The last optimization happened recently");
}
if (roundInProgress) {
log.warn("Trying to change the replication degree another optimization is already in progress");
throw new Exception("Cannot start the next round. Another optimization is in progress");
}
updateNextRoundTimestamp();
}
/**
* it blocks the current thread until the current round is higher or equals to the round id
*
* @param roundId the round id
* @param sender the sender address
* @return true if the round id is ensured, false otherwise (not enabled or interrupted)
*/
public final synchronized boolean ensure(long roundId, Address sender) {
if (!enabled) {
log.warnf("Not possible to ensure round %s. Data placement not enabled", roundId);
return false;
}
if (log.isDebugEnabled()) {
log.debugf("[%s] trying to ensure round %s", Thread.currentThread().getName(), roundId);
}
while (roundId > currentRoundId) {
try {
wait();
} catch (InterruptedException e) {
log.warnf("[%s] interrupted while trying to ensure round %s", Thread.currentThread().getName(), roundId);
return false;
}
}
if (log.isDebugEnabled()) {
log.debugf("[%s] ensured round %s", Thread.currentThread().getName(), roundId);
}
if (!roundInProgress) {
log.warnf("Not possible to process command. No data placement protocol is in progress", roundId);
return false;
}
boolean acceptCommand = roundId == currentRoundId;
if (acceptCommand) {
if (!roundClusterSnapshot.contains(sender)) {
log.warnf("RNot possible to process command. The sender [%s] is not in the current snapshot: %s", sender,
roundClusterSnapshot);
return false;
}
}
return acceptCommand;
}
/**
* invoked in all members when a new round starts
*
* @param roundId the new round id
* @param roundClusterSnapshot the round cluster snapshot
* @param myAddress the node address
*/
public final synchronized boolean startNewRound(long roundId, ClusterSnapshot roundClusterSnapshot, Address myAddress) {
currentRoundId = roundId;
this.roundClusterSnapshot = roundClusterSnapshot;
roundInProgress = roundClusterSnapshot.contains(myAddress);
notifyAll();
if (!roundInProgress) {
log.warnf("Data placement start received but I [%s] am not in the round cluster snapshot: %s", myAddress,
roundClusterSnapshot);
}
return roundInProgress;
}
/**
* mark a current round as finished
*/
public final synchronized void markRoundFinished() {
roundInProgress = false;
}
/**
* returns the current cool down time between data placement rounds
*
* @return the current cool down time between data placement rounds
*/
public final synchronized long getCoolDownTime() {
return coolDownTime;
}
/**
* sets the new cool down time. it only takes effect after the next round
*
* @param coolDownTime the new cool down time in milliseconds
*/
public final synchronized void setCoolDownTime(long coolDownTime) {
this.coolDownTime = coolDownTime;
}
/**
* returns true if a data placement round is in progress
*
* @return true if a data placement round is in progress, false otherwise
*/
public final synchronized boolean isRoundInProgress() {
return roundInProgress;
}
/**
* returns true if the data placement is enabled
*
* @return true if the data placement is enabled, false otherwise
*/
public final synchronized boolean isEnabled() {
return enabled;
}
/**
* updates the cool down time before start a new request
*/
private void updateNextRoundTimestamp() {
nextRoundTimestamp = System.currentTimeMillis() + coolDownTime;
}
}