/**
* Helper method for parallelizing a given fragment. Dependent fragments are parallelized first
* before parallelizing the given fragment.
*/
private void parallelizeFragment(
Wrapper fragmentWrapper,
PlanningSet planningSet,
Collection<DrillbitEndpoint> activeEndpoints)
throws PhysicalOperatorSetupException {
// If the fragment is already parallelized, return.
if (fragmentWrapper.isEndpointsAssignmentDone()) {
return;
}
// First parallelize fragments on which this fragment depends on.
final List<Wrapper> fragmentDependencies = fragmentWrapper.getFragmentDependencies();
if (fragmentDependencies != null && fragmentDependencies.size() > 0) {
for (Wrapper dependency : fragmentDependencies) {
parallelizeFragment(dependency, planningSet, activeEndpoints);
}
}
// Find stats. Stats include various factors including cost of physical operators,
// parallelizability of
// work in physical operator and affinity of physical operator to certain nodes.
fragmentWrapper.getNode().getRoot().accept(new StatsCollector(planningSet), fragmentWrapper);
fragmentWrapper
.getStats()
.getDistributionAffinity()
.getFragmentParallelizer()
.parallelizeFragment(fragmentWrapper, this, activeEndpoints);
}
/**
* Based on the affinity of the Exchange that separates two fragments, setup fragment
* dependencies.
*
* @param planningSet
* @return Returns a list of leaf fragments in fragment dependency graph.
*/
private static Set<Wrapper> constructFragmentDependencyGraph(PlanningSet planningSet) {
// Set up dependency of fragments based on the affinity of exchange that separates the
// fragments.
for (Wrapper currentFragmentWrapper : planningSet) {
ExchangeFragmentPair sendingExchange =
currentFragmentWrapper.getNode().getSendingExchangePair();
if (sendingExchange != null) {
ParallelizationDependency dependency =
sendingExchange.getExchange().getParallelizationDependency();
Wrapper receivingFragmentWrapper = planningSet.get(sendingExchange.getNode());
if (dependency == ParallelizationDependency.RECEIVER_DEPENDS_ON_SENDER) {
receivingFragmentWrapper.addFragmentDependency(currentFragmentWrapper);
} else if (dependency == ParallelizationDependency.SENDER_DEPENDS_ON_RECEIVER) {
currentFragmentWrapper.addFragmentDependency(receivingFragmentWrapper);
}
}
}
// Identify leaf fragments. Leaf fragments are fragments that have no other fragments depending
// on them for
// parallelization info. First assume all fragments are leaf fragments. Go through the fragments
// one by one and
// remove the fragment on which the current fragment depends on.
final Set<Wrapper> roots = Sets.newHashSet();
for (Wrapper w : planningSet) {
roots.add(w);
}
for (Wrapper wrapper : planningSet) {
final List<Wrapper> fragmentDependencies = wrapper.getFragmentDependencies();
if (fragmentDependencies != null && fragmentDependencies.size() > 0) {
for (Wrapper dependency : fragmentDependencies) {
if (roots.contains(dependency)) {
roots.remove(dependency);
}
}
}
}
return roots;
}
private QueryWorkUnit generateWorkUnit(
DrillbitEndpoint foremanNode,
QueryId queryId,
PhysicalPlanReader reader,
Fragment rootNode,
PlanningSet planningSet)
throws ExecutionSetupException {
List<PlanFragment> fragments = Lists.newArrayList();
PlanFragment rootFragment = null;
FragmentRoot rootOperator = null;
long queryStartTime = System.currentTimeMillis();
// now we generate all the individual plan fragments and associated assignments. Note, we need
// all endpoints
// assigned before we can materialize, so we start a new loop here rather than utilizing the
// previous one.
for (Wrapper wrapper : planningSet) {
Fragment node = wrapper.getNode();
Stats stats = node.getStats();
final PhysicalOperator physicalOperatorRoot = node.getRoot();
boolean isRootNode = rootNode == node;
if (isRootNode && wrapper.getWidth() != 1)
throw new FragmentSetupException(
String.format(
"Failure while trying to setup fragment. The root fragment must always have parallelization one. In the current case, the width was set to %d.",
wrapper.getWidth()));
// a fragment is self driven if it doesn't rely on any other exchanges.
boolean isLeafFragment = node.getReceivingExchangePairs().size() == 0;
// Create a minorFragment for each major fragment.
for (int minorFragmentId = 0; minorFragmentId < wrapper.getWidth(); minorFragmentId++) {
IndexedFragmentNode iNode = new IndexedFragmentNode(minorFragmentId, wrapper);
PhysicalOperator op = physicalOperatorRoot.accept(materializer, iNode);
Preconditions.checkArgument(op instanceof FragmentRoot);
FragmentRoot root = (FragmentRoot) op;
// get plan as JSON
String plan;
try {
plan = reader.writeJson(root);
} catch (JsonProcessingException e) {
throw new FragmentSetupException(
"Failure while trying to convert fragment into json.", e);
}
FragmentHandle handle =
FragmentHandle //
.newBuilder() //
.setMajorFragmentId(wrapper.getMajorFragmentId()) //
.setMinorFragmentId(minorFragmentId) //
.setQueryId(queryId) //
.build();
PlanFragment fragment =
PlanFragment.newBuilder() //
.setCpuCost(stats.getCpuCost()) //
.setDiskCost(stats.getDiskCost()) //
.setForeman(foremanNode) //
.setMemoryCost(stats.getMemoryCost()) //
.setNetworkCost(stats.getNetworkCost()) //
.setFragmentJson(plan) //
.setHandle(handle) //
.setAssignment(wrapper.getAssignedEndpoint(minorFragmentId)) //
.setLeafFragment(isLeafFragment) //
.setQueryStartTime(queryStartTime)
.build();
if (isRootNode) {
logger.debug("Root fragment:\n {}", fragment);
rootFragment = fragment;
rootOperator = root;
} else {
logger.debug("Remote fragment:\n {}", fragment);
fragments.add(fragment);
}
}
}
return new QueryWorkUnit(rootOperator, rootFragment, fragments);
}
protected QueryWorkUnit generateWorkUnit(
OptionList options,
DrillbitEndpoint foremanNode,
QueryId queryId,
PhysicalPlanReader reader,
Fragment rootNode,
PlanningSet planningSet,
UserSession session,
QueryContextInformation queryContextInfo)
throws ExecutionSetupException {
List<PlanFragment> fragments = Lists.newArrayList();
PlanFragment rootFragment = null;
FragmentRoot rootOperator = null;
// now we generate all the individual plan fragments and associated assignments. Note, we need
// all endpoints
// assigned before we can materialize, so we start a new loop here rather than utilizing the
// previous one.
for (Wrapper wrapper : planningSet) {
Fragment node = wrapper.getNode();
final PhysicalOperator physicalOperatorRoot = node.getRoot();
boolean isRootNode = rootNode == node;
if (isRootNode && wrapper.getWidth() != 1) {
throw new ForemanSetupException(
String.format(
"Failure while trying to setup fragment. "
+ "The root fragment must always have parallelization one. In the current case, the width was set to %d.",
wrapper.getWidth()));
}
// a fragment is self driven if it doesn't rely on any other exchanges.
boolean isLeafFragment = node.getReceivingExchangePairs().size() == 0;
// Create a minorFragment for each major fragment.
for (int minorFragmentId = 0; minorFragmentId < wrapper.getWidth(); minorFragmentId++) {
IndexedFragmentNode iNode = new IndexedFragmentNode(minorFragmentId, wrapper);
wrapper.resetAllocation();
PhysicalOperator op = physicalOperatorRoot.accept(Materializer.INSTANCE, iNode);
Preconditions.checkArgument(op instanceof FragmentRoot);
FragmentRoot root = (FragmentRoot) op;
// get plan as JSON
String plan;
String optionsData;
try {
plan = reader.writeJson(root);
optionsData = reader.writeJson(options);
} catch (JsonProcessingException e) {
throw new ForemanSetupException("Failure while trying to convert fragment into json.", e);
}
FragmentHandle handle =
FragmentHandle //
.newBuilder() //
.setMajorFragmentId(wrapper.getMajorFragmentId()) //
.setMinorFragmentId(minorFragmentId) //
.setQueryId(queryId) //
.build();
PlanFragment fragment =
PlanFragment.newBuilder() //
.setForeman(foremanNode) //
.setFragmentJson(plan) //
.setHandle(handle) //
.setAssignment(wrapper.getAssignedEndpoint(minorFragmentId)) //
.setLeafFragment(isLeafFragment) //
.setContext(queryContextInfo)
.setMemInitial(wrapper.getInitialAllocation()) //
.setMemMax(wrapper.getMaxAllocation())
.setOptionsJson(optionsData)
.setCredentials(session.getCredentials())
.addAllCollector(CountRequiredFragments.getCollectors(root))
.build();
if (isRootNode) {
logger.debug("Root fragment:\n {}", DrillStringUtils.unescapeJava(fragment.toString()));
rootFragment = fragment;
rootOperator = root;
} else {
logger.debug("Remote fragment:\n {}", DrillStringUtils.unescapeJava(fragment.toString()));
fragments.add(fragment);
}
}
}
return new QueryWorkUnit(rootOperator, rootFragment, fragments);
}
