use of org.apache.drill.exec.planner.fragment.Wrapper in project drill by apache.
the class SplittingParallelizer method generateWorkUnits.
/**
* Split plan into multiple plans based on parallelization
* Ideally it is applicable only to plans with two major fragments: Screen and UnionExchange
* But there could be cases where we can remove even multiple exchanges like in case of "order by"
* End goal is to get single major fragment: Screen with chain that ends up with a single minor fragment
* from Leaf Exchange. This way each plan can run independently without any exchange involvement
* @param options
* @param foremanNode - not really applicable
* @param queryId
* @param reader
* @param rootNode
* @param planningSet
* @param session
* @param queryContextInfo
* @return
* @throws ExecutionSetupException
*/
private List<QueryWorkUnit> generateWorkUnits(OptionList options, DrillbitEndpoint foremanNode, QueryId queryId, PhysicalPlanReader reader, Fragment rootNode, PlanningSet planningSet, UserSession session, QueryContextInformation queryContextInfo) throws ExecutionSetupException {
// 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.
List<QueryWorkUnit> workUnits = Lists.newArrayList();
int plansCount = 0;
DrillbitEndpoint[] endPoints = null;
long initialAllocation = 0;
long maxAllocation = 0;
final Iterator<Wrapper> iter = planningSet.iterator();
while (iter.hasNext()) {
Wrapper wrapper = iter.next();
Fragment node = wrapper.getNode();
boolean isLeafFragment = node.getReceivingExchangePairs().size() == 0;
final PhysicalOperator physicalOperatorRoot = node.getRoot();
// get all the needed info from leaf fragment
if ((physicalOperatorRoot instanceof Exchange) && isLeafFragment) {
// need to get info about
// number of minor fragments
// assignedEndPoints
// allocation
plansCount = wrapper.getWidth();
initialAllocation = (wrapper.getInitialAllocation() != 0) ? wrapper.getInitialAllocation() / plansCount : 0;
maxAllocation = (wrapper.getMaxAllocation() != 0) ? wrapper.getMaxAllocation() / plansCount : 0;
endPoints = new DrillbitEndpoint[plansCount];
for (int mfId = 0; mfId < plansCount; mfId++) {
endPoints[mfId] = wrapper.getAssignedEndpoint(mfId);
}
}
}
if (plansCount == 0) {
// no exchange, return list of single QueryWorkUnit
workUnits.add(generateWorkUnit(options, foremanNode, queryId, reader, rootNode, planningSet, session, queryContextInfo));
return workUnits;
}
for (Wrapper wrapper : planningSet) {
Fragment node = wrapper.getNode();
final PhysicalOperator physicalOperatorRoot = node.getRoot();
if (physicalOperatorRoot instanceof Exchange) {
// get to 0 MajorFragment
continue;
}
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()));
}
// this fragment is always leaf, as we are removing all the exchanges
boolean isLeafFragment = true;
FragmentHandle handle = //
FragmentHandle.newBuilder().setMajorFragmentId(//
wrapper.getMajorFragmentId()).setMinorFragmentId(// minor fragment ID is going to be always 0, as plan will be split
0).setQueryId(//
queryId).build();
// Create a minorFragment for each major fragment.
for (int minorFragmentId = 0; minorFragmentId < plansCount; minorFragmentId++) {
// those fragments should be empty
List<PlanFragment> fragments = Lists.newArrayList();
PlanFragment rootFragment = null;
FragmentRoot rootOperator = null;
IndexedFragmentNode iNode = new IndexedFragmentNode(minorFragmentId, wrapper);
wrapper.resetAllocation();
// two visitors here
// 1. To remove exchange
// 2. To reset operator IDs as exchanges were removed
PhysicalOperator op = physicalOperatorRoot.accept(ExchangeRemoverMaterializer.INSTANCE, iNode).accept(OperatorIdVisitor.INSTANCE, 0);
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);
}
PlanFragment fragment = //
PlanFragment.newBuilder().setForeman(//
endPoints[minorFragmentId]).setFragmentJson(//
plan).setHandle(//
handle).setAssignment(//
endPoints[minorFragmentId]).setLeafFragment(//
isLeafFragment).setContext(queryContextInfo).setMemInitial(//
initialAllocation).setMemMax(// TODO - for some reason OOM is using leaf fragment max allocation divided by width
wrapper.getMaxAllocation()).setOptionsJson(optionsData).setCredentials(session.getCredentials()).addAllCollector(CountRequiredFragments.getCollectors(root)).build();
if (isRootNode) {
if (logger.isDebugEnabled()) {
logger.debug("Root fragment:\n {}", DrillStringUtils.unescapeJava(fragment.toString()));
}
rootFragment = fragment;
rootOperator = root;
} else {
if (logger.isDebugEnabled()) {
logger.debug("Remote fragment:\n {}", DrillStringUtils.unescapeJava(fragment.toString()));
}
throw new ForemanSetupException(String.format("There should not be non-root/remote fragment present in plan split, but there is:", DrillStringUtils.unescapeJava(fragment.toString())));
}
// fragments should be always empty here
workUnits.add(new QueryWorkUnit(rootOperator, rootFragment, fragments));
}
}
return workUnits;
}
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