/**
* This method does bandwidth allocation. This method should be used only for upload bandwidth
* managers.
*
* @param remoteNodeId
* @param message
* @param bytes
* @throws Exception
*/
public Transfer sendBytes(int remoteNodeId, Message message, long bytes) throws Exception {
// System.out.print("Send Bytes: ");
// the delay is only used as a minimum possible delay in case the bandwidth delay is less that
// it
// in other words, the final delay will not be less that 'delay'.
long delay = 0; // delayManager.getDelay(this.nodeId, remoteNodeId);
BandwidthManager remoteBandwidthManager = network.get(remoteNodeId).getDownBandwidthManager();
sanityCheck();
remoteBandwidthManager.sanityCheck();
double bandwidthInBPS =
Math.min(getNextTransferBandwidth(), remoteBandwidthManager.getNextTransferBandwidth());
bandwidthInBPS =
Math.floor(bandwidthInBPS); // to prevent future rounding errors, prevent fractions
// ms = b/(b/ms)
long timeInMilliSec =
Math.max((long) UnitConversion.secToMilliSec(bytes / (bandwidthInBPS)), /*delay*/ 0);
long now = scheduler.now;
message.setDest(remoteNodeId);
message.setSource(this.nodeId);
message.setBytes(bytes);
MessageDeliveryEvent evt = new MessageDeliveryEvent(now + timeInMilliSec, message);
Transfer trns = new Transfer(bandwidthInBPS, this, remoteBandwidthManager, bytes, evt);
message.setTransfer(trns);
trns.setMessage(message); // for debug purposes only
sanityCheck();
remoteBandwidthManager.sanityCheck();
this.makeRoomFor(bandwidthInBPS);
this.availableInBPS -= bandwidthInBPS;
remoteBandwidthManager.makeRoomFor(bandwidthInBPS);
remoteBandwidthManager.availableInBPS -= bandwidthInBPS;
// this must not be done before we call makeRoomFor,
// cuz that function depend on the old size of the transfers array List
// and it depends on the old availableInBPS
transfers.add(trns);
remoteBandwidthManager.transfers.add(trns);
sanityCheck();
remoteBandwidthManager.sanityCheck();
scheduler.enqueue(evt);
P.rint(
"t( "
+ scheduler.now
+ " ) SEND BYTES ("
+ message.getSource()
+ "->"
+ message.getDest()
+ ") "
+ "["
+ bytes
+ " b] , alloc_bw = "
+ bandwidthInBPS
+ " BPS of "
+ totalBandwidthInBPS
+ ", curr_trans = "
+ transfers.size()
+ "/ "
+ remoteBandwidthManager.transfers.size()
+ ", time_est. = "
+ timeInMilliSec
+ " ms, delvr = "
+ evt.getTime()
+ ", "
+ message.toString());
return trns;
}
/**
* This classes is attached to one and only one {@link Node}. It is responsible to manage the
* bandwidth allocation and deallocation on that node. This classes manages several {@link Transfer}
* instances. An instance is either a download manager or an upload manager.
*
* @author meemo
*/
public class BandwidthManager {
// the difference from zero of which we consider a number is zero
static final double BANDWIDTH_TOL = 1;
private Scheduler scheduler = Scheduler.getInstance();
private DelayManager delayManager = DelayManager.getInstance();
private Network network = Network.getInstance();
public long totalBandwidthInBPS;
double availableInBPS;
private int nodeId;
ArrayList<Transfer> transfers = new ArrayList<Transfer>();
public BandwidthManager(long BPS, int nodeId) {
super();
this.availableInBPS = this.totalBandwidthInBPS = BPS;
this.nodeId = nodeId;
}
private double getNextTransferBandwidth() {
return Math.max(availableInBPS, totalBandwidthInBPS / (double) (transfers.size() + 1));
}
/**
* This method will modify the existing transfers. It will only modify those who are taking more
* than their fairshare. It will modify them proportional to their bandwidth, i.e. the more share
* they have, the more they will be cut.
*
* @invariant availableBandwidthInBPS >= bps
* @param bps the target bandwidth
* @throws Exception
*/
private void makeRoomFor(final double bps) throws Exception {
double fairShare = totalBandwidthInBPS / (double) (transfers.size() + 1);
// assert less than fair share
// A.ssert(bps <= getNextTransferBandwidth());
ArrayList<Transfer> trespassingTransfers = new ArrayList<Transfer>();
sanityCheck();
// this will only be true if the fair share is larger than the available bandwidth
if (bps > availableInBPS) // if this is true, then there is trespassing transfers
{
final double amountToReclaim = bps - availableInBPS;
double actualReclaimed = 0;
double total = 0;
for (Transfer t : transfers) {
if (t.bandwidthInBPS > fairShare) {
trespassingTransfers.add(t);
total += t.bandwidthInBPS;
}
}
// sort them ascending by bandwidth
Collections.sort(
trespassingTransfers,
new Comparator<Transfer>() {
public int compare(Transfer o1, Transfer o2) {
return (int) (o1.bandwidthInBPS - o2.bandwidthInBPS);
}
});
double extra = 0;
for (Transfer t : trespassingTransfers) {
double deduction = amountToReclaim * t.bandwidthInBPS / total;
deduction = Math.ceil(deduction); // to prevent future rounding errors, avoid fractions
if (t.bandwidthInBPS - deduction < fairShare) {
double oldDeduction = deduction;
deduction = t.bandwidthInBPS - fairShare;
extra += oldDeduction - deduction;
} else if (t.bandwidthInBPS - deduction > fairShare && extra > 0) {
// take from extra
double oldDeduction = deduction;
double newBW = t.bandwidthInBPS - deduction;
double diffFromFairShare = newBW - fairShare;
if (diffFromFairShare > extra) {
double takeFromExtra = extra;
deduction += takeFromExtra;
} else // diff <= extra
{
double takeFromExtra = diffFromFairShare;
deduction += takeFromExtra;
}
extra -= oldDeduction - deduction;
}
deduction = Math.ceil(deduction);
actualReclaimed += deduction;
BandwidthManager remoteBwm = t.getOtherBandwidthManagerThan(this);
A.ssert(remoteBwm != this);
// remoteBwm.sanityCheck();
if (deduction < BANDWIDTH_TOL) continue;
double newBw = t.bandwidthInBPS - deduction;
t.setNextEpochBW(newBw);
}
HashSet<BandwidthManager> candidates = new HashSet<BandwidthManager>();
for (Transfer t : trespassingTransfers) {
if (t.getNextEpochBW() < 0) continue;
double deducted = t.bandwidthInBPS - t.getNextEpochBW();
t.applyNextEpochBW();
BandwidthManager remoteBWM = t.getOtherBandwidthManagerThan(this);
remoteBWM.availableInBPS += deducted;
candidates.add(remoteBWM);
}
availableInBPS += actualReclaimed;
A.ssert(availableInBPS > bps || Math.abs(availableInBPS - bps) < BANDWIDTH_TOL);
// we are going to lie about our available bandwidth cuz we are reserving bps of them.
// availableInBPS -= bps;
double oldVal = availableInBPS;
availableInBPS = 0;
for (BandwidthManager bwm : candidates) bwm.boostLocalTransfers();
// availableInBPS += bps;
availableInBPS = oldVal;
}
A.ssert(availableInBPS > bps || Math.abs(availableInBPS - bps) < BANDWIDTH_TOL);
}
/*
* This method is called upon returning bandwidth to availabeInBPS
* and we want the current transfers to make use of it.
*/
public void boostLocalTransfers() throws Exception {
if (transfers.isEmpty()
|| this.nodeId == /*backup source*/ 30
|| this.transfers.size() > 50 /*effectively means that each transfer fair share is < 2% */)
return;
// sanityCheck();
P.rint(this.nodeId + " boosting local transfers");
ArrayList<Transfer> looseTransfers = new ArrayList<Transfer>();
for (Transfer t : transfers) {
t.updatedLooseValue();
if (Math.floor(t.looseValue) > BANDWIDTH_TOL) {
looseTransfers.add(t);
}
}
int loops = 0;
while (!(looseTransfers.isEmpty()
|| availableInBPS < BANDWIDTH_TOL * (looseTransfers.size()))) {
loops++;
Set<BandwidthManager> candidates = new HashSet<BandwidthManager>();
double error = 0;
for (Transfer t : looseTransfers) {
double added = t.looseValue;
added = Math.floor(added); // to prevent future rounding errors, remove fractions
error += t.looseValue - added;
if (added < BANDWIDTH_TOL) continue;
candidates.add(t.getOtherBandwidthManagerThan(this));
t.setNextEpochBW(t.bandwidthInBPS + added);
}
int errorBytes = (int) error;
for (Transfer t : looseTransfers) {
A.ssert(t.getNextEpochBW() > 0);
double added = t.getNextEpochBW() - t.bandwidthInBPS;
t.applyNextEpochBW();
t.sourceBandwidthManager.availableInBPS -= added;
t.destBandwidthManager.availableInBPS -= added;
}
ArrayList<Transfer> stillLoose = new ArrayList<Transfer>();
for (Transfer t : looseTransfers) {
t.updatedLooseValue();
if (Math.floor(t.looseValue) > BANDWIDTH_TOL) {
stillLoose.add(t);
}
}
looseTransfers = stillLoose;
if (errorBytes < totalBandwidthInBPS * 2.0 / 100) break;
}
// for(Transfer t : transfers)
// {
// A.ssert(!t.loose());
// }
P.rint("boosting done in " + loops + " loops");
}
// FIXME assure this function is transitive...
double preferredAddTo(Transfer t) {
final double boostTol = 1; // // don't boost connections below 10 Kbps
if (this.availableInBPS < BANDWIDTH_TOL
|| Math.min(t.sourceBandwidthManager.availableInBPS, t.destBandwidthManager.availableInBPS)
< BANDWIDTH_TOL * boostTol) return 0;
double usedBw = 0; // BPS - availableInBPS;
int numLoose = 0;
for (Transfer t1 : transfers)
if (Math.min(t1.sourceBandwidthManager.availableInBPS, t1.destBandwidthManager.availableInBPS)
> BANDWIDTH_TOL * boostTol) {
usedBw += t1.bandwidthInBPS;
numLoose++;
}
double retval = 0;
if (usedBw > 0) retval = availableInBPS * t.bandwidthInBPS / usedBw;
else retval = 0; // */
// double retval = availableInBPS/transfers.size();
// retval = Math.floor(retval); // to prevent future rounding errors, remove fractions
return retval;
}
// private double preferredAddTo(Transfer t) {
// int numLoose = 0;
// for(Transfer t1 : transfers)
// if(t1.loose())
// numLoose++;
// double retval = availableInBPS / numLoose;
//
// retval = Math.floor(retval); // to prevent future rounding errors, remove fractions
//
// return retval;
// }
/**
* This method does bandwidth allocation. This method should be used only for upload bandwidth
* managers.
*
* @param remoteNodeId
* @param message
* @param bytes
* @throws Exception
*/
public Transfer sendBytes(int remoteNodeId, Message message, long bytes) throws Exception {
// System.out.print("Send Bytes: ");
// the delay is only used as a minimum possible delay in case the bandwidth delay is less that
// it
// in other words, the final delay will not be less that 'delay'.
long delay = 0; // delayManager.getDelay(this.nodeId, remoteNodeId);
BandwidthManager remoteBandwidthManager = network.get(remoteNodeId).getDownBandwidthManager();
sanityCheck();
remoteBandwidthManager.sanityCheck();
double bandwidthInBPS =
Math.min(getNextTransferBandwidth(), remoteBandwidthManager.getNextTransferBandwidth());
bandwidthInBPS =
Math.floor(bandwidthInBPS); // to prevent future rounding errors, prevent fractions
// ms = b/(b/ms)
long timeInMilliSec =
Math.max((long) UnitConversion.secToMilliSec(bytes / (bandwidthInBPS)), /*delay*/ 0);
long now = scheduler.now;
message.setDest(remoteNodeId);
message.setSource(this.nodeId);
message.setBytes(bytes);
MessageDeliveryEvent evt = new MessageDeliveryEvent(now + timeInMilliSec, message);
Transfer trns = new Transfer(bandwidthInBPS, this, remoteBandwidthManager, bytes, evt);
message.setTransfer(trns);
trns.setMessage(message); // for debug purposes only
sanityCheck();
remoteBandwidthManager.sanityCheck();
this.makeRoomFor(bandwidthInBPS);
this.availableInBPS -= bandwidthInBPS;
remoteBandwidthManager.makeRoomFor(bandwidthInBPS);
remoteBandwidthManager.availableInBPS -= bandwidthInBPS;
// this must not be done before we call makeRoomFor,
// cuz that function depend on the old size of the transfers array List
// and it depends on the old availableInBPS
transfers.add(trns);
remoteBandwidthManager.transfers.add(trns);
sanityCheck();
remoteBandwidthManager.sanityCheck();
scheduler.enqueue(evt);
P.rint(
"t( "
+ scheduler.now
+ " ) SEND BYTES ("
+ message.getSource()
+ "->"
+ message.getDest()
+ ") "
+ "["
+ bytes
+ " b] , alloc_bw = "
+ bandwidthInBPS
+ " BPS of "
+ totalBandwidthInBPS
+ ", curr_trans = "
+ transfers.size()
+ "/ "
+ remoteBandwidthManager.transfers.size()
+ ", time_est. = "
+ timeInMilliSec
+ " ms, delvr = "
+ evt.getTime()
+ ", "
+ message.toString());
return trns;
}
/*
* Make sure that available bandwidth + used bandwidth sum to the original total bandwidth
*/
private void sanityCheck() throws Exception {
if (Math.abs(availableInBPS) < BANDWIDTH_TOL / 10) availableInBPS = 0;
if (Math.abs(availableInBPS - totalBandwidthInBPS) < BANDWIDTH_TOL / 10)
availableInBPS = totalBandwidthInBPS;
if (!Conf.BW_SANITY_CHECK) return;
A.ssert(totalBandwidthInBPS >= -BANDWIDTH_TOL);
A.ssert(availableInBPS >= -BANDWIDTH_TOL);
if (totalBandwidthInBPS - availableInBPS < -BANDWIDTH_TOL)
A.ssert(totalBandwidthInBPS - availableInBPS >= BANDWIDTH_TOL);
sumUsedSanityCheck();
}
private void sumUsedSanityCheck() throws Exception {
if (!Conf.BW_SANITY_CHECK) return;
if (transfers.isEmpty()) A.ssert(availableInBPS == totalBandwidthInBPS);
double usedBandwidth = 0;
for (Transfer t : transfers) {
if (t.deliveryEvent.time < scheduler.now) A.ssert(t.deliveryEvent.time >= scheduler.now);
usedBandwidth += t.bandwidthInBPS;
}
if (Math.abs(((usedBandwidth + availableInBPS) - this.totalBandwidthInBPS) / transfers.size())
> BANDWIDTH_TOL)
A.ssert(
Math.abs(((usedBandwidth + availableInBPS) - this.totalBandwidthInBPS))
< BANDWIDTH_TOL); // equality test
}
/**
* This method deallocated bandwidth This method should be used only for download bandwidth
* managers.
*
* @param transfer
* @throws Exception
*/
public void receive(Transfer transfer) throws Exception {
// can't assert that in fail mode
// FIXME return the assertion in non-fail mode
// if(transfer.deliveryEvent.time != scheduler.now)
// A.ssert(transfer.deliveryEvent.time == scheduler.now);
if (transfer.failed) return;
sanityCheck();
transfer.getSourceBandwidthManager().sanityCheck();
this.availableInBPS += transfer.bandwidthInBPS;
transfers.remove(transfer);
transfer.getSourceBandwidthManager().availableInBPS += transfer.bandwidthInBPS;
transfer.getSourceBandwidthManager().transfers.remove(transfer);
sanityCheck();
transfer.getSourceBandwidthManager().sanityCheck();
transfer.sourceBandwidthManager.boostLocalTransfers();
transfer.destBandwidthManager.boostLocalTransfers();
sanityCheck();
transfer.getSourceBandwidthManager().sanityCheck();
P.rint(
"t("
+ scheduler.now
+ ") RECV BYTES "
+ transfer.getSourceBandwidthManager().getNodeId()
+ "-->"
+ transfer.getDestBandwidthManager().getNodeId()
+ " <"
+ transfer.getMessage().seqNum
+ "> / "
+ transfer.originalStartTime
+ ", curr_trans = "
+ transfer.getSourceBandwidthManager().transfers.size()
+ ", curr_bw="
+ availableInBPS
+ " out of "
+ totalBandwidthInBPS);
}
public int getNodeId() {
return nodeId;
}
public ArrayList<Transfer> getTranfers() {
return transfers;
}
public void fail() throws Exception {
while (!transfers.isEmpty()) transfers.get(0).fail();
}
}
