Examples with ParallelizationDependency org.apache.drill.exec.physical.base.Exchange.ParallelizationDependency used on opensource projects

Example 1 with ParallelizationDependency

use of org.apache.drill.exec.physical.base.Exchange.ParallelizationDependency in project drill by apache.

the class SimpleParallelizer method constructFragmentDependencyGraph.

/**
   * 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;
}