private void createCopier(
VectorAccessible batch,
List<BatchGroup> batchGroupList,
VectorContainer outputContainer,
boolean spilling)
throws SchemaChangeException {
try {
if (copier == null) {
CodeGenerator<PriorityQueueCopier> cg =
CodeGenerator.get(
PriorityQueueCopier.TEMPLATE_DEFINITION,
context.getFunctionRegistry(),
context.getOptions());
ClassGenerator<PriorityQueueCopier> g = cg.getRoot();
generateComparisons(g, batch);
g.setMappingSet(COPIER_MAPPING_SET);
CopyUtil.generateCopies(g, batch, true);
g.setMappingSet(MAIN_MAPPING);
copier = context.getImplementationClass(cg);
} else {
copier.close();
}
BufferAllocator allocator = spilling ? copierAllocator : oAllocator;
for (VectorWrapper<?> i : batch) {
ValueVector v = TypeHelper.getNewVector(i.getField(), allocator);
outputContainer.add(v);
}
copier.setup(context, allocator, batch, batchGroupList, outputContainer);
} catch (ClassTransformationException | IOException e) {
throw new RuntimeException(e);
}
}
@Override
public void close() {
try {
if (batchGroups != null) {
closeBatchGroups(batchGroups);
batchGroups = null;
}
if (spilledBatchGroups != null) {
closeBatchGroups(spilledBatchGroups);
spilledBatchGroups = null;
}
} finally {
if (builder != null) {
builder.clear();
builder.close();
}
if (sv4 != null) {
sv4.clear();
}
try {
if (copier != null) {
copier.close();
}
} catch (IOException e) {
throw new RuntimeException(e);
} finally {
copierAllocator.close();
super.close();
if (mSorter != null) {
mSorter.clear();
}
for (Iterator iter = this.currSpillDirs.iterator(); iter.hasNext(); iter.remove()) {
Path path = (Path) iter.next();
try {
if (fs != null && path != null && fs.exists(path)) {
if (fs.delete(path, true)) {
fs.cancelDeleteOnExit(path);
}
}
} catch (IOException e) {
// since this is meant to be used in a batches's cleanup, we don't propagate the
// exception
logger.warn("Unable to delete spill directory " + path, e);
}
}
}
}
}
public BatchGroup mergeAndSpill(LinkedList<BatchGroup> batchGroups) throws SchemaChangeException {
logger.debug("Copier allocator current allocation {}", copierAllocator.getAllocatedMemory());
logger.debug(
"mergeAndSpill: starting total size in memory = {}", oAllocator.getAllocatedMemory());
VectorContainer outputContainer = new VectorContainer();
List<BatchGroup> batchGroupList = Lists.newArrayList();
int batchCount = batchGroups.size();
for (int i = 0; i < batchCount / 2; i++) {
if (batchGroups.size() == 0) {
break;
}
BatchGroup batch = batchGroups.pollLast();
assert batch != null : "Encountered a null batch during merge and spill operation";
batchGroupList.add(batch);
}
if (batchGroupList.size() == 0) {
return null;
}
int estimatedRecordSize = 0;
for (VectorWrapper<?> w : batchGroupList.get(0)) {
try {
estimatedRecordSize += TypeHelper.getSize(w.getField().getType());
} catch (UnsupportedOperationException e) {
estimatedRecordSize += 50;
}
}
int targetRecordCount = Math.max(1, COPIER_BATCH_MEM_LIMIT / estimatedRecordSize);
VectorContainer hyperBatch = constructHyperBatch(batchGroupList);
createCopier(hyperBatch, batchGroupList, outputContainer, true);
int count = copier.next(targetRecordCount);
assert count > 0;
logger.debug(
"mergeAndSpill: estimated record size = {}, target record count = {}",
estimatedRecordSize,
targetRecordCount);
// 1 output container is kept in memory, so we want to hold on to it and transferClone
// allows keeping ownership
VectorContainer c1 = VectorContainer.getTransferClone(outputContainer, oContext);
c1.buildSchema(BatchSchema.SelectionVectorMode.NONE);
c1.setRecordCount(count);
String spillDir = dirs.next();
Path currSpillPath = new Path(Joiner.on("/").join(spillDir, fileName));
currSpillDirs.add(currSpillPath);
String outputFile = Joiner.on("/").join(currSpillPath, spillCount++);
try {
fs.deleteOnExit(currSpillPath);
} catch (IOException e) {
// since this is meant to be used in a batches's spilling, we don't propagate the exception
logger.warn("Unable to mark spill directory " + currSpillPath + " for deleting on exit", e);
}
stats.setLongStat(Metric.SPILL_COUNT, spillCount);
BatchGroup newGroup = new BatchGroup(c1, fs, outputFile, oContext);
try (AutoCloseable a = AutoCloseables.all(batchGroupList)) {
logger.info("Merging and spilling to {}", outputFile);
while ((count = copier.next(targetRecordCount)) > 0) {
outputContainer.buildSchema(BatchSchema.SelectionVectorMode.NONE);
outputContainer.setRecordCount(count);
// note that addBatch also clears the outputContainer
newGroup.addBatch(outputContainer);
}
injector.injectChecked(
context.getExecutionControls(), INTERRUPTION_WHILE_SPILLING, IOException.class);
newGroup.closeOutputStream();
} catch (Throwable e) {
// we only need to cleanup newGroup if spill failed
try {
AutoCloseables.close(e, newGroup);
} catch (Throwable t) {
/* close() may hit the same IO issue; just ignore */
}
throw UserException.resourceError(e)
.message("External Sort encountered an error while spilling to disk")
.addContext(e.getMessage() /* more detail */)
.build(logger);
} finally {
hyperBatch.clear();
}
logger.debug("mergeAndSpill: final total size in memory = {}", oAllocator.getAllocatedMemory());
logger.info("Completed spilling to {}", outputFile);
return newGroup;
}
@Override
public IterOutcome innerNext() {
if (schema != null) {
if (spillCount == 0) {
return (getSelectionVector4().next()) ? IterOutcome.OK : IterOutcome.NONE;
} else {
Stopwatch w = Stopwatch.createStarted();
int count = copier.next(targetRecordCount);
if (count > 0) {
long t = w.elapsed(TimeUnit.MICROSECONDS);
logger.debug("Took {} us to merge {} records", t, count);
container.setRecordCount(count);
return IterOutcome.OK;
} else {
logger.debug("copier returned 0 records");
return IterOutcome.NONE;
}
}
}
int totalCount = 0;
int totalBatches = 0; // total number of batches received so far
try {
container.clear();
outer:
while (true) {
IterOutcome upstream;
if (first) {
upstream = IterOutcome.OK_NEW_SCHEMA;
} else {
upstream = next(incoming);
}
if (upstream == IterOutcome.OK && sorter == null) {
upstream = IterOutcome.OK_NEW_SCHEMA;
}
switch (upstream) {
case NONE:
if (first) {
return upstream;
}
break outer;
case NOT_YET:
throw new UnsupportedOperationException();
case STOP:
return upstream;
case OK_NEW_SCHEMA:
case OK:
VectorContainer convertedBatch;
// only change in the case that the schema truly changes. Artificial schema changes are
// ignored.
if (upstream == IterOutcome.OK_NEW_SCHEMA && !incoming.getSchema().equals(schema)) {
if (schema != null) {
if (unionTypeEnabled) {
this.schema = SchemaUtil.mergeSchemas(schema, incoming.getSchema());
} else {
throw new SchemaChangeException(
"Schema changes not supported in External Sort. Please enable Union type");
}
} else {
schema = incoming.getSchema();
}
convertedBatch = SchemaUtil.coerceContainer(incoming, schema, oContext);
for (BatchGroup b : batchGroups) {
b.setSchema(schema);
}
for (BatchGroup b : spilledBatchGroups) {
b.setSchema(schema);
}
this.sorter = createNewSorter(context, convertedBatch);
} else {
convertedBatch = SchemaUtil.coerceContainer(incoming, schema, oContext);
}
if (first) {
first = false;
}
if (convertedBatch.getRecordCount() == 0) {
for (VectorWrapper<?> w : convertedBatch) {
w.clear();
}
break;
}
SelectionVector2 sv2;
if (incoming.getSchema().getSelectionVectorMode()
== BatchSchema.SelectionVectorMode.TWO_BYTE) {
sv2 = incoming.getSelectionVector2().clone();
} else {
try {
sv2 = newSV2();
} catch (InterruptedException e) {
return IterOutcome.STOP;
} catch (OutOfMemoryException e) {
throw new OutOfMemoryException(e);
}
}
int count = sv2.getCount();
totalCount += count;
totalBatches++;
sorter.setup(context, sv2, convertedBatch);
sorter.sort(sv2);
RecordBatchData rbd = new RecordBatchData(convertedBatch, oAllocator);
boolean success = false;
try {
rbd.setSv2(sv2);
batchGroups.add(new BatchGroup(rbd.getContainer(), rbd.getSv2(), oContext));
if (peakNumBatches < batchGroups.size()) {
peakNumBatches = batchGroups.size();
stats.setLongStat(Metric.PEAK_BATCHES_IN_MEMORY, peakNumBatches);
}
batchesSinceLastSpill++;
if ( // If we haven't spilled so far, do we have enough memory for MSorter if this
// turns out to be the last incoming batch?
(spillCount == 0 && !hasMemoryForInMemorySort(totalCount))
||
// If we haven't spilled so far, make sure we don't exceed the maximum number of
// batches SV4 can address
(spillCount == 0 && totalBatches > Character.MAX_VALUE)
||
// TODO(DRILL-4438) - consider setting this threshold more intelligently,
// lowering caused a failing low memory condition (test in
// BasicPhysicalOpUnitTest)
// to complete successfully (although it caused perf decrease as there was more
// spilling)
// current memory used is more than 95% of memory usage limit of this operator
(oAllocator.getAllocatedMemory() > .95 * oAllocator.getLimit())
||
// Number of incoming batches (BatchGroups) exceed the limit and number of
// incoming batches accumulated
// since the last spill exceed the defined limit
(batchGroups.size() > SPILL_THRESHOLD
&& batchesSinceLastSpill >= SPILL_BATCH_GROUP_SIZE)) {
if (firstSpillBatchCount == 0) {
firstSpillBatchCount = batchGroups.size();
}
if (spilledBatchGroups.size() > firstSpillBatchCount / 2) {
logger.info("Merging spills");
final BatchGroup merged = mergeAndSpill(spilledBatchGroups);
if (merged != null) {
spilledBatchGroups.addFirst(merged);
}
}
final BatchGroup merged = mergeAndSpill(batchGroups);
if (merged != null) { // make sure we don't add null to spilledBatchGroups
spilledBatchGroups.add(merged);
batchesSinceLastSpill = 0;
}
}
success = true;
} finally {
if (!success) {
rbd.clear();
}
}
break;
case OUT_OF_MEMORY:
logger.debug("received OUT_OF_MEMORY, trying to spill");
if (batchesSinceLastSpill > 2) {
final BatchGroup merged = mergeAndSpill(batchGroups);
if (merged != null) {
spilledBatchGroups.add(merged);
batchesSinceLastSpill = 0;
}
} else {
logger.debug("not enough batches to spill, sending OUT_OF_MEMORY downstream");
return IterOutcome.OUT_OF_MEMORY;
}
break;
default:
throw new UnsupportedOperationException();
}
}
if (totalCount == 0) {
return IterOutcome.NONE;
}
if (spillCount == 0) {
if (builder != null) {
builder.clear();
builder.close();
}
builder = new SortRecordBatchBuilder(oAllocator);
for (BatchGroup group : batchGroups) {
RecordBatchData rbd = new RecordBatchData(group.getContainer(), oAllocator);
rbd.setSv2(group.getSv2());
builder.add(rbd);
}
builder.build(context, container);
sv4 = builder.getSv4();
mSorter = createNewMSorter();
mSorter.setup(context, oAllocator, getSelectionVector4(), this.container);
// For testing memory-leak purpose, inject exception after mSorter finishes setup
injector.injectUnchecked(context.getExecutionControls(), INTERRUPTION_AFTER_SETUP);
mSorter.sort(this.container);
// sort may have prematurely exited due to should continue returning false.
if (!context.shouldContinue()) {
return IterOutcome.STOP;
}
// For testing memory-leak purpose, inject exception after mSorter finishes sorting
injector.injectUnchecked(context.getExecutionControls(), INTERRUPTION_AFTER_SORT);
sv4 = mSorter.getSV4();
container.buildSchema(SelectionVectorMode.FOUR_BYTE);
} else { // some batches were spilled
final BatchGroup merged = mergeAndSpill(batchGroups);
if (merged != null) {
spilledBatchGroups.add(merged);
}
batchGroups.addAll(spilledBatchGroups);
spilledBatchGroups =
null; // no need to cleanup spilledBatchGroups, all it's batches are in batchGroups now
logger.warn(
"Starting to merge. {} batch groups. Current allocated memory: {}",
batchGroups.size(),
oAllocator.getAllocatedMemory());
VectorContainer hyperBatch = constructHyperBatch(batchGroups);
createCopier(hyperBatch, batchGroups, container, false);
int estimatedRecordSize = 0;
for (VectorWrapper<?> w : batchGroups.get(0)) {
try {
estimatedRecordSize += TypeHelper.getSize(w.getField().getType());
} catch (UnsupportedOperationException e) {
estimatedRecordSize += 50;
}
}
targetRecordCount =
Math.min(MAX_BATCH_SIZE, Math.max(1, COPIER_BATCH_MEM_LIMIT / estimatedRecordSize));
int count = copier.next(targetRecordCount);
container.buildSchema(SelectionVectorMode.NONE);
container.setRecordCount(count);
}
return IterOutcome.OK_NEW_SCHEMA;
} catch (SchemaChangeException ex) {
kill(false);
context.fail(
UserException.unsupportedError(ex)
.message("Sort doesn't currently support sorts with changing schemas")
.build(logger));
return IterOutcome.STOP;
} catch (ClassTransformationException | IOException ex) {
kill(false);
context.fail(ex);
return IterOutcome.STOP;
} catch (UnsupportedOperationException e) {
throw new RuntimeException(e);
}
}
