Module org.elasticsearch.compute

Package org.elasticsearch.compute.lucene.query

Enum Class LuceneSliceQueue.PartitioningStrategy

java.lang.Object

java.lang.Enum<LuceneSliceQueue.PartitioningStrategy>

org.elasticsearch.compute.lucene.query.LuceneSliceQueue.PartitioningStrategy

All Implemented Interfaces:

Serializable, Comparable<LuceneSliceQueue.PartitioningStrategy>, Constable, Writeable

Enclosing class:

LuceneSliceQueue

public static enum LuceneSliceQueue.PartitioningStrategy
extends Enum<LuceneSliceQueue.PartitioningStrategy>
implements Writeable

Strategy used to partition each shard into slices. See DataPartitioning for descriptions on how each value works.

Nested Class Summary

Nested classes/interfaces inherited from class java.lang.Enum

Enum.EnumDesc<E extends Enum<E>>

Nested classes/interfaces inherited from interface org.elasticsearch.common.io.stream.Writeable

Writeable.Reader<V>, Writeable.Writer<V>

Enum Constant Summary

Enum Constants

Enum Constant	Description
DOC	See DataPartitioning.DOC.
SEGMENT	See DataPartitioning.SEGMENT.
SHARD	See DataPartitioning.SHARD.
TIME_SERIES	Partition using the prefix of tsid

Method Summary

Modifier and Type	Method	Description
static LuceneSliceQueue.PartitioningStrategy	readFrom(StreamInput in)
static LuceneSliceQueue.PartitioningStrategy	valueOf(String name)	Returns the enum constant of this class with the specified name.
static LuceneSliceQueue.PartitioningStrategy[]	values()	Returns an array containing the constants of this enum class, in the order they are declared.
void	writeTo(StreamOutput out)

Methods inherited from class java.lang.Enum

clone, compareTo, describeConstable, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Details

SHARD

public static final LuceneSliceQueue.PartitioningStrategy SHARD

See DataPartitioning.SHARD.

SEGMENT

public static final LuceneSliceQueue.PartitioningStrategy SEGMENT

See DataPartitioning.SEGMENT.

Segments are never split — each leaf stays whole. Small segments are bin-packed together so that each slice carries at least LuceneSliceQueue.MIN_DOCS_PER_SLICE docs (or its fair share, totalDocs / taskConcurrency, whichever is larger). The total slice count is capped at taskConcurrency. This delegates to ContextIndexSearcher.computeSlices(java.util.List<org.apache.lucene.index.LeafReaderContext>, int, int), which is the same algorithm the regular _search API uses — so the SEGMENT floor matches the DOC floor.

DOC

public static final LuceneSliceQueue.PartitioningStrategy DOC

See DataPartitioning.DOC.

Aims for taskConcurrency slices: desiredSliceSize = clamp(totalDocs / taskConcurrency, minDocsPerSlice, MAX_DOCS_PER_SLICE). minDocsPerSlice defaults to LuceneSliceQueue.MIN_DOCS_PER_SLICE but may be lowered per query (via the min_docs_per_slice pragma) so small-index tests can still exercise multi-slice partitioning. maxSegmentsPerSlice scales with totalSegments / taskConcurrency (with a LuceneSliceQueue.MAX_SEGMENTS_PER_SLICE floor) so that a heavily fragmented index doesn't force a slice count well above the chosen parallelism.

When the largest unguarded segment is within ~1.5× of desiredSliceSize, every non-guarded leaf can be kept whole; we then balance leaves across taskConcurrency slices via worst-fit-decreasing bin packing (preserving segment boundaries) instead of splitting segments through LuceneSliceQueue.AdaptivePartitioner.

If the supplied LuceneSliceQueue.LeafSplitGuard marks a leaf as "keep whole" for the supplied Weight (e.g. LuceneCountOperator's Weight.count(LeafReaderContext) shortcut), that leaf is emitted as a single full-leaf slice and skipped by both the splitter and the bin-packer.

TIME_SERIES

public static final LuceneSliceQueue.PartitioningStrategy TIME_SERIES

Partition using the prefix of tsid

Method Details

values

public static LuceneSliceQueue.PartitioningStrategy[] values()

Returns an array containing the constants of this enum class, in the order they are declared.

Returns:

an array containing the constants of this enum class, in the order they are declared

valueOf

public static LuceneSliceQueue.PartitioningStrategy valueOf(String name)

Returns the enum constant of this class with the specified name. The string must match exactly an identifier used to declare an enum constant in this class. (Extraneous whitespace characters are not permitted.)

Parameters:

name - the name of the enum constant to be returned.

Returns:

the enum constant with the specified name

Throws:

IllegalArgumentException - if this enum class has no constant with the specified name

NullPointerException - if the argument is null

readFrom

public static LuceneSliceQueue.PartitioningStrategy readFrom(StreamInput in)
                                                      throws IOException

Throws:

IOException

writeTo

public void writeTo(StreamOutput out)
             throws IOException

Specified by:

writeTo in interface Writeable

Throws:

IOException