1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
|
package spark.broadcast
import java.io._
import java.net._
import java.util.{BitSet, Comparator, Timer, TimerTask, UUID}
import java.util.concurrent.atomic.AtomicInteger
import scala.collection.mutable.{ListBuffer, Map, Set}
import scala.math
import spark._
import spark.storage.StorageLevel
private[spark] class BitTorrentBroadcast[T](@transient var value_ : T, isLocal: Boolean, id: Long)
extends Broadcast[T](id)
with Logging
with Serializable {
def value = value_
def blockId: String = "broadcast_" + id
MultiTracker.synchronized {
SparkEnv.get.blockManager.putSingle(blockId, value_, StorageLevel.MEMORY_AND_DISK, false)
}
@transient var arrayOfBlocks: Array[BroadcastBlock] = null
@transient var hasBlocksBitVector: BitSet = null
@transient var numCopiesSent: Array[Int] = null
@transient var totalBytes = -1
@transient var totalBlocks = -1
@transient var hasBlocks = new AtomicInteger(0)
// Used ONLY by driver to track how many unique blocks have been sent out
@transient var sentBlocks = new AtomicInteger(0)
@transient var listenPortLock = new Object
@transient var guidePortLock = new Object
@transient var totalBlocksLock = new Object
@transient var listOfSources = ListBuffer[SourceInfo]()
@transient var serveMR: ServeMultipleRequests = null
// Used only in driver
@transient var guideMR: GuideMultipleRequests = null
// Used only in Workers
@transient var ttGuide: TalkToGuide = null
@transient var hostAddress = Utils.localIpAddress
@transient var listenPort = -1
@transient var guidePort = -1
@transient var stopBroadcast = false
// Must call this after all the variables have been created/initialized
if (!isLocal) {
sendBroadcast()
}
def sendBroadcast() {
logInfo("Local host address: " + hostAddress)
// Create a variableInfo object and store it in valueInfos
var variableInfo = MultiTracker.blockifyObject(value_)
// Prepare the value being broadcasted
arrayOfBlocks = variableInfo.arrayOfBlocks
totalBytes = variableInfo.totalBytes
totalBlocks = variableInfo.totalBlocks
hasBlocks.set(variableInfo.totalBlocks)
// Guide has all the blocks
hasBlocksBitVector = new BitSet(totalBlocks)
hasBlocksBitVector.set(0, totalBlocks)
// Guide still hasn't sent any block
numCopiesSent = new Array[Int](totalBlocks)
guideMR = new GuideMultipleRequests
guideMR.setDaemon(true)
guideMR.start()
logInfo("GuideMultipleRequests started...")
// Must always come AFTER guideMR is created
while (guidePort == -1) {
guidePortLock.synchronized { guidePortLock.wait() }
}
serveMR = new ServeMultipleRequests
serveMR.setDaemon(true)
serveMR.start()
logInfo("ServeMultipleRequests started...")
// Must always come AFTER serveMR is created
while (listenPort == -1) {
listenPortLock.synchronized { listenPortLock.wait() }
}
// Must always come AFTER listenPort is created
val driverSource =
SourceInfo(hostAddress, listenPort, totalBlocks, totalBytes)
hasBlocksBitVector.synchronized {
driverSource.hasBlocksBitVector = hasBlocksBitVector
}
// In the beginning, this is the only known source to Guide
listOfSources += driverSource
// Register with the Tracker
MultiTracker.registerBroadcast(id,
SourceInfo(hostAddress, guidePort, totalBlocks, totalBytes))
}
private def readObject(in: ObjectInputStream) {
in.defaultReadObject()
MultiTracker.synchronized {
SparkEnv.get.blockManager.getSingle(blockId) match {
case Some(x) =>
value_ = x.asInstanceOf[T]
case None =>
logInfo("Started reading broadcast variable " + id)
// Initializing everything because driver will only send null/0 values
// Only the 1st worker in a node can be here. Others will get from cache
initializeWorkerVariables()
logInfo("Local host address: " + hostAddress)
// Start local ServeMultipleRequests thread first
serveMR = new ServeMultipleRequests
serveMR.setDaemon(true)
serveMR.start()
logInfo("ServeMultipleRequests started...")
val start = System.nanoTime
val receptionSucceeded = receiveBroadcast(id)
if (receptionSucceeded) {
value_ = MultiTracker.unBlockifyObject[T](arrayOfBlocks, totalBytes, totalBlocks)
SparkEnv.get.blockManager.putSingle(
blockId, value_, StorageLevel.MEMORY_AND_DISK, false)
} else {
logError("Reading broadcast variable " + id + " failed")
}
val time = (System.nanoTime - start) / 1e9
logInfo("Reading broadcast variable " + id + " took " + time + " s")
}
}
}
// Initialize variables in the worker node. Driver sends everything as 0/null
private def initializeWorkerVariables() {
arrayOfBlocks = null
hasBlocksBitVector = null
numCopiesSent = null
totalBytes = -1
totalBlocks = -1
hasBlocks = new AtomicInteger(0)
listenPortLock = new Object
totalBlocksLock = new Object
serveMR = null
ttGuide = null
hostAddress = Utils.localIpAddress
listenPort = -1
listOfSources = ListBuffer[SourceInfo]()
stopBroadcast = false
}
private def getLocalSourceInfo: SourceInfo = {
// Wait till hostName and listenPort are OK
while (listenPort == -1) {
listenPortLock.synchronized { listenPortLock.wait() }
}
// Wait till totalBlocks and totalBytes are OK
while (totalBlocks == -1) {
totalBlocksLock.synchronized { totalBlocksLock.wait() }
}
var localSourceInfo = SourceInfo(
hostAddress, listenPort, totalBlocks, totalBytes)
localSourceInfo.hasBlocks = hasBlocks.get
hasBlocksBitVector.synchronized {
localSourceInfo.hasBlocksBitVector = hasBlocksBitVector
}
return localSourceInfo
}
// Add new SourceInfo to the listOfSources. Update if it exists already.
// Optimizing just by OR-ing the BitVectors was BAD for performance
private def addToListOfSources(newSourceInfo: SourceInfo) {
listOfSources.synchronized {
if (listOfSources.contains(newSourceInfo)) {
listOfSources = listOfSources - newSourceInfo
}
listOfSources += newSourceInfo
}
}
private def addToListOfSources(newSourceInfos: ListBuffer[SourceInfo]) {
newSourceInfos.foreach { newSourceInfo =>
addToListOfSources(newSourceInfo)
}
}
class TalkToGuide(gInfo: SourceInfo)
extends Thread with Logging {
override def run() {
// Keep exchaning information until all blocks have been received
while (hasBlocks.get < totalBlocks) {
talkOnce
Thread.sleep(MultiTracker.ranGen.nextInt(
MultiTracker.MaxKnockInterval - MultiTracker.MinKnockInterval) +
MultiTracker.MinKnockInterval)
}
// Talk one more time to let the Guide know of reception completion
talkOnce
}
// Connect to Guide and send this worker's information
private def talkOnce {
var clientSocketToGuide: Socket = null
var oosGuide: ObjectOutputStream = null
var oisGuide: ObjectInputStream = null
clientSocketToGuide = new Socket(gInfo.hostAddress, gInfo.listenPort)
oosGuide = new ObjectOutputStream(clientSocketToGuide.getOutputStream)
oosGuide.flush()
oisGuide = new ObjectInputStream(clientSocketToGuide.getInputStream)
// Send local information
oosGuide.writeObject(getLocalSourceInfo)
oosGuide.flush()
// Receive source information from Guide
var suitableSources =
oisGuide.readObject.asInstanceOf[ListBuffer[SourceInfo]]
logDebug("Received suitableSources from Driver " + suitableSources)
addToListOfSources(suitableSources)
oisGuide.close()
oosGuide.close()
clientSocketToGuide.close()
}
}
def receiveBroadcast(variableID: Long): Boolean = {
val gInfo = MultiTracker.getGuideInfo(variableID)
if (gInfo.listenPort == SourceInfo.TxOverGoToDefault) {
return false
}
// Wait until hostAddress and listenPort are created by the
// ServeMultipleRequests thread
while (listenPort == -1) {
listenPortLock.synchronized { listenPortLock.wait() }
}
// Setup initial states of variables
totalBlocks = gInfo.totalBlocks
arrayOfBlocks = new Array[BroadcastBlock](totalBlocks)
hasBlocksBitVector = new BitSet(totalBlocks)
numCopiesSent = new Array[Int](totalBlocks)
totalBlocksLock.synchronized { totalBlocksLock.notifyAll() }
totalBytes = gInfo.totalBytes
// Start ttGuide to periodically talk to the Guide
var ttGuide = new TalkToGuide(gInfo)
ttGuide.setDaemon(true)
ttGuide.start()
logInfo("TalkToGuide started...")
// Start pController to run TalkToPeer threads
var pcController = new PeerChatterController
pcController.setDaemon(true)
pcController.start()
logInfo("PeerChatterController started...")
// FIXME: Must fix this. This might never break if broadcast fails.
// We should be able to break and send false. Also need to kill threads
while (hasBlocks.get < totalBlocks) {
Thread.sleep(MultiTracker.MaxKnockInterval)
}
return true
}
class PeerChatterController
extends Thread with Logging {
private var peersNowTalking = ListBuffer[SourceInfo]()
// TODO: There is a possible bug with blocksInRequestBitVector when a
// certain bit is NOT unset upon failure resulting in an infinite loop.
private var blocksInRequestBitVector = new BitSet(totalBlocks)
override def run() {
var threadPool = Utils.newDaemonFixedThreadPool(MultiTracker.MaxChatSlots)
while (hasBlocks.get < totalBlocks) {
var numThreadsToCreate = 0
listOfSources.synchronized {
numThreadsToCreate = math.min(listOfSources.size, MultiTracker.MaxChatSlots) -
threadPool.getActiveCount
}
while (hasBlocks.get < totalBlocks && numThreadsToCreate > 0) {
var peerToTalkTo = pickPeerToTalkToRandom
if (peerToTalkTo != null)
logDebug("Peer chosen: " + peerToTalkTo + " with " + peerToTalkTo.hasBlocksBitVector)
else
logDebug("No peer chosen...")
if (peerToTalkTo != null) {
threadPool.execute(new TalkToPeer(peerToTalkTo))
// Add to peersNowTalking. Remove in the thread. We have to do this
// ASAP, otherwise pickPeerToTalkTo picks the same peer more than once
peersNowTalking.synchronized { peersNowTalking += peerToTalkTo }
}
numThreadsToCreate = numThreadsToCreate - 1
}
// Sleep for a while before starting some more threads
Thread.sleep(MultiTracker.MinKnockInterval)
}
// Shutdown the thread pool
threadPool.shutdown()
}
// Right now picking the one that has the most blocks this peer wants
// Also picking peer randomly if no one has anything interesting
private def pickPeerToTalkToRandom: SourceInfo = {
var curPeer: SourceInfo = null
var curMax = 0
logDebug("Picking peers to talk to...")
// Find peers that are not connected right now
var peersNotInUse = ListBuffer[SourceInfo]()
listOfSources.synchronized {
peersNowTalking.synchronized {
peersNotInUse = listOfSources -- peersNowTalking
}
}
// Select the peer that has the most blocks that this receiver does not
peersNotInUse.foreach { eachSource =>
var tempHasBlocksBitVector: BitSet = null
hasBlocksBitVector.synchronized {
tempHasBlocksBitVector = hasBlocksBitVector.clone.asInstanceOf[BitSet]
}
tempHasBlocksBitVector.flip(0, tempHasBlocksBitVector.size)
tempHasBlocksBitVector.and(eachSource.hasBlocksBitVector)
if (tempHasBlocksBitVector.cardinality > curMax) {
curPeer = eachSource
curMax = tempHasBlocksBitVector.cardinality
}
}
// Always picking randomly
if (curPeer == null && peersNotInUse.size > 0) {
// Pick uniformly the i'th required peer
var i = MultiTracker.ranGen.nextInt(peersNotInUse.size)
var peerIter = peersNotInUse.iterator
curPeer = peerIter.next
while (i > 0) {
curPeer = peerIter.next
i = i - 1
}
}
return curPeer
}
// Picking peer with the weight of rare blocks it has
private def pickPeerToTalkToRarestFirst: SourceInfo = {
// Find peers that are not connected right now
var peersNotInUse = ListBuffer[SourceInfo]()
listOfSources.synchronized {
peersNowTalking.synchronized {
peersNotInUse = listOfSources -- peersNowTalking
}
}
// Count the number of copies of each block in the neighborhood
var numCopiesPerBlock = Array.tabulate [Int](totalBlocks)(_ => 0)
listOfSources.synchronized {
listOfSources.foreach { eachSource =>
for (i <- 0 until totalBlocks) {
numCopiesPerBlock(i) +=
( if (eachSource.hasBlocksBitVector.get(i)) 1 else 0 )
}
}
}
// A block is considered rare if there are at most 2 copies of that block
// This CONSTANT could be a function of the neighborhood size
var rareBlocksIndices = ListBuffer[Int]()
for (i <- 0 until totalBlocks) {
if (numCopiesPerBlock(i) > 0 && numCopiesPerBlock(i) <= 2) {
rareBlocksIndices += i
}
}
// Find peers with rare blocks
var peersWithRareBlocks = ListBuffer[(SourceInfo, Int)]()
var totalRareBlocks = 0
peersNotInUse.foreach { eachPeer =>
var hasRareBlocks = 0
rareBlocksIndices.foreach { rareBlock =>
if (eachPeer.hasBlocksBitVector.get(rareBlock)) {
hasRareBlocks += 1
}
}
if (hasRareBlocks > 0) {
peersWithRareBlocks += ((eachPeer, hasRareBlocks))
}
totalRareBlocks += hasRareBlocks
}
// Select a peer from peersWithRareBlocks based on weight calculated from
// unique rare blocks
var selectedPeerToTalkTo: SourceInfo = null
if (peersWithRareBlocks.size > 0) {
// Sort the peers based on how many rare blocks they have
peersWithRareBlocks.sortBy(_._2)
var randomNumber = MultiTracker.ranGen.nextDouble
var tempSum = 0.0
var i = 0
do {
tempSum += (1.0 * peersWithRareBlocks(i)._2 / totalRareBlocks)
if (tempSum >= randomNumber) {
selectedPeerToTalkTo = peersWithRareBlocks(i)._1
}
i += 1
} while (i < peersWithRareBlocks.size && selectedPeerToTalkTo == null)
}
if (selectedPeerToTalkTo == null) {
selectedPeerToTalkTo = pickPeerToTalkToRandom
}
return selectedPeerToTalkTo
}
class TalkToPeer(peerToTalkTo: SourceInfo)
extends Thread with Logging {
private var peerSocketToSource: Socket = null
private var oosSource: ObjectOutputStream = null
private var oisSource: ObjectInputStream = null
override def run() {
// TODO: There is a possible bug here regarding blocksInRequestBitVector
var blockToAskFor = -1
// Setup the timeout mechanism
var timeOutTask = new TimerTask {
override def run() {
cleanUpConnections()
}
}
var timeOutTimer = new Timer
timeOutTimer.schedule(timeOutTask, MultiTracker.MaxKnockInterval)
logInfo("TalkToPeer started... => " + peerToTalkTo)
try {
// Connect to the source
peerSocketToSource =
new Socket(peerToTalkTo.hostAddress, peerToTalkTo.listenPort)
oosSource =
new ObjectOutputStream(peerSocketToSource.getOutputStream)
oosSource.flush()
oisSource =
new ObjectInputStream(peerSocketToSource.getInputStream)
// Receive latest SourceInfo from peerToTalkTo
var newPeerToTalkTo = oisSource.readObject.asInstanceOf[SourceInfo]
// Update listOfSources
addToListOfSources(newPeerToTalkTo)
// Turn the timer OFF, if the sender responds before timeout
timeOutTimer.cancel()
// Send the latest SourceInfo
oosSource.writeObject(getLocalSourceInfo)
oosSource.flush()
var keepReceiving = true
while (hasBlocks.get < totalBlocks && keepReceiving) {
blockToAskFor =
pickBlockRandom(newPeerToTalkTo.hasBlocksBitVector)
// No block to request
if (blockToAskFor < 0) {
// Nothing to receive from newPeerToTalkTo
keepReceiving = false
} else {
// Let other threads know that blockToAskFor is being requested
blocksInRequestBitVector.synchronized {
blocksInRequestBitVector.set(blockToAskFor)
}
// Start with sending the blockID
oosSource.writeObject(blockToAskFor)
oosSource.flush()
// CHANGED: Driver might send some other block than the one
// requested to ensure fast spreading of all blocks.
val recvStartTime = System.currentTimeMillis
val bcBlock = oisSource.readObject.asInstanceOf[BroadcastBlock]
val receptionTime = (System.currentTimeMillis - recvStartTime)
logDebug("Received block: " + bcBlock.blockID + " from " + peerToTalkTo + " in " + receptionTime + " millis.")
if (!hasBlocksBitVector.get(bcBlock.blockID)) {
arrayOfBlocks(bcBlock.blockID) = bcBlock
// Update the hasBlocksBitVector first
hasBlocksBitVector.synchronized {
hasBlocksBitVector.set(bcBlock.blockID)
hasBlocks.getAndIncrement
}
// Some block(may NOT be blockToAskFor) has arrived.
// In any case, blockToAskFor is not in request any more
blocksInRequestBitVector.synchronized {
blocksInRequestBitVector.set(blockToAskFor, false)
}
// Reset blockToAskFor to -1. Else it will be considered missing
blockToAskFor = -1
}
// Send the latest SourceInfo
oosSource.writeObject(getLocalSourceInfo)
oosSource.flush()
}
}
} catch {
// EOFException is expected to happen because sender can break
// connection due to timeout
case eofe: java.io.EOFException => { }
case e: Exception => {
logError("TalktoPeer had a " + e)
// FIXME: Remove 'newPeerToTalkTo' from listOfSources
// We probably should have the following in some form, but not
// really here. This exception can happen if the sender just breaks connection
// listOfSources.synchronized {
// logInfo("Exception in TalkToPeer. Removing source: " + peerToTalkTo)
// listOfSources = listOfSources - peerToTalkTo
// }
}
} finally {
// blockToAskFor != -1 => there was an exception
if (blockToAskFor != -1) {
blocksInRequestBitVector.synchronized {
blocksInRequestBitVector.set(blockToAskFor, false)
}
}
cleanUpConnections()
}
}
// Right now it picks a block uniformly that this peer does not have
private def pickBlockRandom(txHasBlocksBitVector: BitSet): Int = {
var needBlocksBitVector: BitSet = null
// Blocks already present
hasBlocksBitVector.synchronized {
needBlocksBitVector = hasBlocksBitVector.clone.asInstanceOf[BitSet]
}
// Include blocks already in transmission ONLY IF
// MultiTracker.EndGameFraction has NOT been achieved
if ((1.0 * hasBlocks.get / totalBlocks) < MultiTracker.EndGameFraction) {
blocksInRequestBitVector.synchronized {
needBlocksBitVector.or(blocksInRequestBitVector)
}
}
// Find blocks that are neither here nor in transit
needBlocksBitVector.flip(0, needBlocksBitVector.size)
// Blocks that should/can be requested
needBlocksBitVector.and(txHasBlocksBitVector)
if (needBlocksBitVector.cardinality == 0) {
return -1
} else {
// Pick uniformly the i'th required block
var i = MultiTracker.ranGen.nextInt(needBlocksBitVector.cardinality)
var pickedBlockIndex = needBlocksBitVector.nextSetBit(0)
while (i > 0) {
pickedBlockIndex =
needBlocksBitVector.nextSetBit(pickedBlockIndex + 1)
i -= 1
}
return pickedBlockIndex
}
}
// Pick the block that seems to be the rarest across sources
private def pickBlockRarestFirst(txHasBlocksBitVector: BitSet): Int = {
var needBlocksBitVector: BitSet = null
// Blocks already present
hasBlocksBitVector.synchronized {
needBlocksBitVector = hasBlocksBitVector.clone.asInstanceOf[BitSet]
}
// Include blocks already in transmission ONLY IF
// MultiTracker.EndGameFraction has NOT been achieved
if ((1.0 * hasBlocks.get / totalBlocks) < MultiTracker.EndGameFraction) {
blocksInRequestBitVector.synchronized {
needBlocksBitVector.or(blocksInRequestBitVector)
}
}
// Find blocks that are neither here nor in transit
needBlocksBitVector.flip(0, needBlocksBitVector.size)
// Blocks that should/can be requested
needBlocksBitVector.and(txHasBlocksBitVector)
if (needBlocksBitVector.cardinality == 0) {
return -1
} else {
// Count the number of copies for each block across all sources
var numCopiesPerBlock = Array.tabulate [Int](totalBlocks)(_ => 0)
listOfSources.synchronized {
listOfSources.foreach { eachSource =>
for (i <- 0 until totalBlocks) {
numCopiesPerBlock(i) +=
( if (eachSource.hasBlocksBitVector.get(i)) 1 else 0 )
}
}
}
// Find the minimum
var minVal = Integer.MAX_VALUE
for (i <- 0 until totalBlocks) {
if (numCopiesPerBlock(i) > 0 && numCopiesPerBlock(i) < minVal) {
minVal = numCopiesPerBlock(i)
}
}
// Find the blocks with the least copies that this peer does not have
var minBlocksIndices = ListBuffer[Int]()
for (i <- 0 until totalBlocks) {
if (needBlocksBitVector.get(i) && numCopiesPerBlock(i) == minVal) {
minBlocksIndices += i
}
}
// Now select a random index from minBlocksIndices
if (minBlocksIndices.size == 0) {
return -1
} else {
// Pick uniformly the i'th index
var i = MultiTracker.ranGen.nextInt(minBlocksIndices.size)
return minBlocksIndices(i)
}
}
}
private def cleanUpConnections() {
if (oisSource != null) {
oisSource.close()
}
if (oosSource != null) {
oosSource.close()
}
if (peerSocketToSource != null) {
peerSocketToSource.close()
}
// Delete from peersNowTalking
peersNowTalking.synchronized { peersNowTalking -= peerToTalkTo }
}
}
}
class GuideMultipleRequests
extends Thread with Logging {
// Keep track of sources that have completed reception
private var setOfCompletedSources = Set[SourceInfo]()
override def run() {
var threadPool = Utils.newDaemonCachedThreadPool()
var serverSocket: ServerSocket = null
serverSocket = new ServerSocket(0)
guidePort = serverSocket.getLocalPort
logInfo("GuideMultipleRequests => " + serverSocket + " " + guidePort)
guidePortLock.synchronized { guidePortLock.notifyAll() }
try {
while (!stopBroadcast) {
var clientSocket: Socket = null
try {
serverSocket.setSoTimeout(MultiTracker.ServerSocketTimeout)
clientSocket = serverSocket.accept()
} catch {
case e: Exception => {
// Stop broadcast if at least one worker has connected and
// everyone connected so far are done. Comparing with
// listOfSources.size - 1, because it includes the Guide itself
listOfSources.synchronized {
setOfCompletedSources.synchronized {
if (listOfSources.size > 1 &&
setOfCompletedSources.size == listOfSources.size - 1) {
stopBroadcast = true
logInfo("GuideMultipleRequests Timeout. stopBroadcast == true.")
}
}
}
}
}
if (clientSocket != null) {
logDebug("Guide: Accepted new client connection:" + clientSocket)
try {
threadPool.execute(new GuideSingleRequest(clientSocket))
} catch {
// In failure, close the socket here; else, thread will close it
case ioe: IOException => {
clientSocket.close()
}
}
}
}
// Shutdown the thread pool
threadPool.shutdown()
logInfo("Sending stopBroadcast notifications...")
sendStopBroadcastNotifications
MultiTracker.unregisterBroadcast(id)
} finally {
if (serverSocket != null) {
logInfo("GuideMultipleRequests now stopping...")
serverSocket.close()
}
}
}
private def sendStopBroadcastNotifications() {
listOfSources.synchronized {
listOfSources.foreach { sourceInfo =>
var guideSocketToSource: Socket = null
var gosSource: ObjectOutputStream = null
var gisSource: ObjectInputStream = null
try {
// Connect to the source
guideSocketToSource = new Socket(sourceInfo.hostAddress, sourceInfo.listenPort)
gosSource = new ObjectOutputStream(guideSocketToSource.getOutputStream)
gosSource.flush()
gisSource = new ObjectInputStream(guideSocketToSource.getInputStream)
// Throw away whatever comes in
gisSource.readObject.asInstanceOf[SourceInfo]
// Send stopBroadcast signal. listenPort = SourceInfo.StopBroadcast
gosSource.writeObject(SourceInfo("", SourceInfo.StopBroadcast))
gosSource.flush()
} catch {
case e: Exception => {
logError("sendStopBroadcastNotifications had a " + e)
}
} finally {
if (gisSource != null) {
gisSource.close()
}
if (gosSource != null) {
gosSource.close()
}
if (guideSocketToSource != null) {
guideSocketToSource.close()
}
}
}
}
}
class GuideSingleRequest(val clientSocket: Socket)
extends Thread with Logging {
private val oos = new ObjectOutputStream(clientSocket.getOutputStream)
oos.flush()
private val ois = new ObjectInputStream(clientSocket.getInputStream)
private var sourceInfo: SourceInfo = null
private var selectedSources: ListBuffer[SourceInfo] = null
override def run() {
try {
logInfo("new GuideSingleRequest is running")
// Connecting worker is sending in its information
sourceInfo = ois.readObject.asInstanceOf[SourceInfo]
// Select a suitable source and send it back to the worker
selectedSources = selectSuitableSources(sourceInfo)
logDebug("Sending selectedSources:" + selectedSources)
oos.writeObject(selectedSources)
oos.flush()
// Add this source to the listOfSources
addToListOfSources(sourceInfo)
} catch {
case e: Exception => {
// Assuming exception caused by receiver failure: remove
if (listOfSources != null) {
listOfSources.synchronized { listOfSources -= sourceInfo }
}
}
} finally {
logInfo("GuideSingleRequest is closing streams and sockets")
ois.close()
oos.close()
clientSocket.close()
}
}
// Randomly select some sources to send back
private def selectSuitableSources(skipSourceInfo: SourceInfo): ListBuffer[SourceInfo] = {
var selectedSources = ListBuffer[SourceInfo]()
// If skipSourceInfo.hasBlocksBitVector has all bits set to 'true'
// then add skipSourceInfo to setOfCompletedSources. Return blank.
if (skipSourceInfo.hasBlocks == totalBlocks) {
setOfCompletedSources.synchronized { setOfCompletedSources += skipSourceInfo }
return selectedSources
}
listOfSources.synchronized {
if (listOfSources.size <= MultiTracker.MaxPeersInGuideResponse) {
selectedSources = listOfSources.clone
} else {
var picksLeft = MultiTracker.MaxPeersInGuideResponse
var alreadyPicked = new BitSet(listOfSources.size)
while (picksLeft > 0) {
var i = -1
do {
i = MultiTracker.ranGen.nextInt(listOfSources.size)
} while (alreadyPicked.get(i))
var peerIter = listOfSources.iterator
var curPeer = peerIter.next
// Set the BitSet before i is decremented
alreadyPicked.set(i)
while (i > 0) {
curPeer = peerIter.next
i = i - 1
}
selectedSources += curPeer
picksLeft = picksLeft - 1
}
}
}
// Remove the receiving source (if present)
selectedSources = selectedSources - skipSourceInfo
return selectedSources
}
}
}
class ServeMultipleRequests
extends Thread with Logging {
// Server at most MultiTracker.MaxChatSlots peers
var threadPool = Utils.newDaemonFixedThreadPool(MultiTracker.MaxChatSlots)
override def run() {
var serverSocket = new ServerSocket(0)
listenPort = serverSocket.getLocalPort
logInfo("ServeMultipleRequests started with " + serverSocket)
listenPortLock.synchronized { listenPortLock.notifyAll() }
try {
while (!stopBroadcast) {
var clientSocket: Socket = null
try {
serverSocket.setSoTimeout(MultiTracker.ServerSocketTimeout)
clientSocket = serverSocket.accept()
} catch {
case e: Exception => { }
}
if (clientSocket != null) {
logDebug("Serve: Accepted new client connection:" + clientSocket)
try {
threadPool.execute(new ServeSingleRequest(clientSocket))
} catch {
// In failure, close socket here; else, the thread will close it
case ioe: IOException => clientSocket.close()
}
}
}
} finally {
if (serverSocket != null) {
logInfo("ServeMultipleRequests now stopping...")
serverSocket.close()
}
}
// Shutdown the thread pool
threadPool.shutdown()
}
class ServeSingleRequest(val clientSocket: Socket)
extends Thread with Logging {
private val oos = new ObjectOutputStream(clientSocket.getOutputStream)
oos.flush()
private val ois = new ObjectInputStream(clientSocket.getInputStream)
logInfo("new ServeSingleRequest is running")
override def run() {
try {
// Send latest local SourceInfo to the receiver
// In the case of receiver timeout and connection close, this will
// throw a java.net.SocketException: Broken pipe
oos.writeObject(getLocalSourceInfo)
oos.flush()
// Receive latest SourceInfo from the receiver
var rxSourceInfo = ois.readObject.asInstanceOf[SourceInfo]
if (rxSourceInfo.listenPort == SourceInfo.StopBroadcast) {
stopBroadcast = true
} else {
addToListOfSources(rxSourceInfo)
}
val startTime = System.currentTimeMillis
var curTime = startTime
var keepSending = true
var numBlocksToSend = MultiTracker.MaxChatBlocks
while (!stopBroadcast && keepSending && numBlocksToSend > 0) {
// Receive which block to send
var blockToSend = ois.readObject.asInstanceOf[Int]
// If it is driver AND at least one copy of each block has not been
// sent out already, MODIFY blockToSend
if (MultiTracker.isDriver && sentBlocks.get < totalBlocks) {
blockToSend = sentBlocks.getAndIncrement
}
// Send the block
sendBlock(blockToSend)
rxSourceInfo.hasBlocksBitVector.set(blockToSend)
numBlocksToSend -= 1
// Receive latest SourceInfo from the receiver
rxSourceInfo = ois.readObject.asInstanceOf[SourceInfo]
logDebug("rxSourceInfo: " + rxSourceInfo + " with " + rxSourceInfo.hasBlocksBitVector)
addToListOfSources(rxSourceInfo)
curTime = System.currentTimeMillis
// Revoke sending only if there is anyone waiting in the queue
if (curTime - startTime >= MultiTracker.MaxChatTime &&
threadPool.getQueue.size > 0) {
keepSending = false
}
}
} catch {
case e: Exception => logError("ServeSingleRequest had a " + e)
} finally {
logInfo("ServeSingleRequest is closing streams and sockets")
ois.close()
oos.close()
clientSocket.close()
}
}
private def sendBlock(blockToSend: Int) {
try {
oos.writeObject(arrayOfBlocks(blockToSend))
oos.flush()
} catch {
case e: Exception => logError("sendBlock had a " + e)
}
logDebug("Sent block: " + blockToSend + " to " + clientSocket)
}
}
}
}
private[spark] class BitTorrentBroadcastFactory
extends BroadcastFactory {
def initialize(isDriver: Boolean) { MultiTracker.initialize(isDriver) }
def newBroadcast[T](value_ : T, isLocal: Boolean, id: Long) =
new BitTorrentBroadcast[T](value_, isLocal, id)
def stop() { MultiTracker.stop() }
}
|