Package io.trino.execution.scheduler

Interface NodeSelector

All Known Implementing Classes:

TopologyAwareNodeSelector, UniformNodeSelector

public interface NodeSelector

Method Summary

Modifier and Type	Method	Description
List<InternalNode>	allNodes()
SplitPlacementResult	computeAssignments(Set<Split> splits, List<RemoteTask> existingTasks)	Identifies the nodes for running the specified splits.
SplitPlacementResult	computeAssignments(Set<Split> splits, List<RemoteTask> existingTasks, BucketNodeMap bucketNodeMap)	Identifies the nodes for running the specified splits based on a precomputed fixed partitioning.
void	lockDownNodes()
InternalNode	selectCurrentNode()
default List<InternalNode>	selectRandomNodes(int limit)
List<InternalNode>	selectRandomNodes(int limit, Set<InternalNode> excludedNodes)

Method Details

lockDownNodes

void lockDownNodes()

allNodes

List<InternalNode> allNodes()

selectCurrentNode

InternalNode selectCurrentNode()

selectRandomNodes

default List<InternalNode> selectRandomNodes(int limit)

selectRandomNodes

List<InternalNode> selectRandomNodes(int limit,
 Set<InternalNode> excludedNodes)

computeAssignments

SplitPlacementResult computeAssignments(Set<Split> splits,
 List<RemoteTask> existingTasks)

Identifies the nodes for running the specified splits.

Parameters:

splits - the splits that need to be assigned to nodes

Returns:

a multimap from node to splits only for splits for which we could identify a node to schedule on. If we cannot find an assignment for a split, it is not included in the map. Also returns a future indicating when to reattempt scheduling of this batch of splits, if some of them could not be scheduled.

computeAssignments

SplitPlacementResult computeAssignments(Set<Split> splits,
 List<RemoteTask> existingTasks,
 BucketNodeMap bucketNodeMap)

Identifies the nodes for running the specified splits based on a precomputed fixed partitioning.

Parameters:

splits - the splits that need to be assigned to nodes

Returns:

a multimap from node to splits only for splits for which we could identify a node with free space. If we cannot find an assignment for a split, it is not included in the map. Also returns a future indicating when to reattempt scheduling of this batch of splits, if some of them could not be scheduled.