org.apache.druid.query.timeseries

Class TimeseriesQueryQueryToolChest

java.lang.Object

org.apache.druid.query.QueryToolChest<Result<TimeseriesResultValue>,TimeseriesQuery>

org.apache.druid.query.timeseries.TimeseriesQueryQueryToolChest

public class TimeseriesQueryQueryToolChest
extends QueryToolChest<Result<TimeseriesResultValue>,TimeseriesQuery>

Constructor Summary

Constructors

Constructor and Description
TimeseriesQueryQueryToolChest()
TimeseriesQueryQueryToolChest(TimeseriesQueryMetricsFactory queryMetricsFactory)

Method Summary

Modifier and Type	Method and Description
BinaryOperator<Result<TimeseriesResultValue>>	createMergeFn(Query<Result<TimeseriesResultValue>> query) Creates a merge function that is used to merge intermediate aggregates from historicals in broker.
Comparator<Result<TimeseriesResultValue>>	createResultComparator(Query<Result<TimeseriesResultValue>> query) Creates an ordering comparator that is used to order results.
CacheStrategy<Result<TimeseriesResultValue>,Object,TimeseriesQuery>	getCacheStrategy(TimeseriesQuery query) Returns a CacheStrategy to be used to load data into the cache and remove it from the cache.
com.fasterxml.jackson.core.type.TypeReference<Result<TimeseriesResultValue>>	getResultTypeReference() Returns a TypeReference object that is just passed through to Jackson in order to deserialize the results of this type of query.
TimeseriesQueryMetrics	makeMetrics(TimeseriesQuery query) Creates a QueryMetrics object that is used to generate metrics for this specific query type.
com.google.common.base.Function<Result<TimeseriesResultValue>,Result<TimeseriesResultValue>>	makePostComputeManipulatorFn(TimeseriesQuery query, MetricManipulationFn fn) Generally speaking this is the exact same thing as makePreComputeManipulatorFn.
com.google.common.base.Function<Result<TimeseriesResultValue>,Result<TimeseriesResultValue>>	makePreComputeManipulatorFn(TimeseriesQuery query, MetricManipulationFn fn) Creates a Function that can take in a ResultType and return a new ResultType having applied the MetricManipulatorFn to each of the metrics.
QueryRunner<Result<TimeseriesResultValue>>	mergeResults(QueryRunner<Result<TimeseriesResultValue>> queryRunner) This method wraps a QueryRunner.
QueryRunner<Result<TimeseriesResultValue>>	preMergeQueryDecoration(QueryRunner<Result<TimeseriesResultValue>> runner) Wraps a QueryRunner.
RowSignature	resultArraySignature(TimeseriesQuery query) Returns a RowSignature for the arrays returned by QueryToolChest.resultsAsArrays(QueryType, org.apache.druid.java.util.common.guava.Sequence<ResultType>).
Sequence<Object[]>	resultsAsArrays(TimeseriesQuery query, Sequence<Result<TimeseriesResultValue>> resultSequence) Converts a sequence of this query's ResultType into arrays.
Optional<Sequence<FrameSignaturePair>>	resultsAsFrames(TimeseriesQuery query, Sequence<Result<TimeseriesResultValue>> resultSequence, MemoryAllocatorFactory memoryAllocatorFactory, boolean useNestedForUnknownTypes) This returns a single frame containing the results of the timeseries query

Methods inherited from class org.apache.druid.query.QueryToolChest

canPerformSubquery, decorateObjectMapper, filterSegments, getBaseResultType, getBySegmentResultType, postMergeQueryDecoration

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

TimeseriesQueryQueryToolChest

public TimeseriesQueryQueryToolChest()

TimeseriesQueryQueryToolChest

@Inject
public TimeseriesQueryQueryToolChest(TimeseriesQueryMetricsFactory queryMetricsFactory)

Method Detail

mergeResults

public QueryRunner<Result<TimeseriesResultValue>> mergeResults(QueryRunner<Result<TimeseriesResultValue>> queryRunner)

Description copied from class: QueryToolChest

This method wraps a QueryRunner. The input QueryRunner, by contract, will provide a series of ResultType objects in time order (ascending or descending). This method should return a new QueryRunner that potentially merges the stream of ordered ResultType objects. A default implementation constructs a ResultMergeQueryRunner which creates a CombiningSequence using the supplied QueryRunner with QueryToolChest.createResultComparator(Query) and QueryToolChest.createMergeFn(Query)} supplied by this toolchest.

Overrides:

mergeResults in class QueryToolChest<Result<TimeseriesResultValue>,TimeseriesQuery>

Parameters:

queryRunner - A QueryRunner that provides a series of ResultType objects in time order (ascending or descending)

Returns:

a QueryRunner that potentially merges the stream of ordered ResultType objects

createMergeFn

public BinaryOperator<Result<TimeseriesResultValue>> createMergeFn(Query<Result<TimeseriesResultValue>> query)

Description copied from class: QueryToolChest

Creates a merge function that is used to merge intermediate aggregates from historicals in broker. This merge function is used in the default ResultMergeQueryRunner provided by QueryToolChest.mergeResults(QueryRunner) and also used in ParallelMergeCombiningSequence by 'CachingClusteredClient' if it does not return null. Returning null from this function means that a query does not support result merging, at least via the mechanisms that utilize this function.

Overrides:

createMergeFn in class QueryToolChest<Result<TimeseriesResultValue>,TimeseriesQuery>

createResultComparator

public Comparator<Result<TimeseriesResultValue>> createResultComparator(Query<Result<TimeseriesResultValue>> query)

Description copied from class: QueryToolChest

Creates an ordering comparator that is used to order results. This comparator is used in the default ResultMergeQueryRunner provided by QueryToolChest.mergeResults(QueryRunner)

Overrides:

createResultComparator in class QueryToolChest<Result<TimeseriesResultValue>,TimeseriesQuery>

makeMetrics

public TimeseriesQueryMetrics makeMetrics(TimeseriesQuery query)

Description copied from class: QueryToolChest

Creates a QueryMetrics object that is used to generate metrics for this specific query type. This exists to allow for query-specific dimensions and metrics. That is, the ToolChest is expected to set some meaningful dimensions for metrics given this query type. Examples might be the topN threshold for a TopN query or the number of dimensions included for a groupBy query.

QueryToolChests for query types in core (druid-processing) and public extensions (belonging to the Druid source tree) should use delegate this method to GenericQueryMetricsFactory.makeMetrics(Query) on an injected instance of GenericQueryMetricsFactory, as long as they don't need to emit custom dimensions and/or metrics.

If some custom dimensions and/or metrics should be emitted for a query type, a plan described in "Making subinterfaces of QueryMetrics" section in QueryMetrics's class-level Javadocs should be followed.

One way or another, this method should ensure that QueryMetrics.query(Query) is called with the given query passed on the created QueryMetrics object before returning.

Specified by:

makeMetrics in class QueryToolChest<Result<TimeseriesResultValue>,TimeseriesQuery>

Parameters:

query - The query that is being processed

Returns:

A QueryMetrics that can be used to make metrics for the provided query

getResultTypeReference

public com.fasterxml.jackson.core.type.TypeReference<Result<TimeseriesResultValue>> getResultTypeReference()

Description copied from class: QueryToolChest

Returns a TypeReference object that is just passed through to Jackson in order to deserialize the results of this type of query.

Specified by:

getResultTypeReference in class QueryToolChest<Result<TimeseriesResultValue>,TimeseriesQuery>

Returns:

A TypeReference to indicate to Jackson what type of data will exist for this query

getCacheStrategy

public CacheStrategy<Result<TimeseriesResultValue>,Object,TimeseriesQuery> getCacheStrategy(TimeseriesQuery query)

Description copied from class: QueryToolChest

Returns a CacheStrategy to be used to load data into the cache and remove it from the cache.

This is optional. If it returns null, caching is effectively disabled for the query.

Overrides:

getCacheStrategy in class QueryToolChest<Result<TimeseriesResultValue>,TimeseriesQuery>

Parameters:

query - The query whose results might be cached

Returns:

A CacheStrategy that can be used to populate and read from the Cache

preMergeQueryDecoration

public QueryRunner<Result<TimeseriesResultValue>> preMergeQueryDecoration(QueryRunner<Result<TimeseriesResultValue>> runner)

Description copied from class: QueryToolChest

Wraps a QueryRunner. The input QueryRunner is the QueryRunner as it exists *before* being passed to mergeResults().

In fact, the return value of this method is always passed to mergeResults, so it is equivalent to just implement this functionality as extra decoration on the QueryRunner during mergeResults().

In the interests of potentially simplifying these interfaces, the recommendation is to actually not override this method and instead apply anything that might be needed here in the mergeResults() call.

Overrides:

preMergeQueryDecoration in class QueryToolChest<Result<TimeseriesResultValue>,TimeseriesQuery>

Parameters:

runner - The runner to be wrapped

Returns:

The wrapped runner

makePreComputeManipulatorFn

public com.google.common.base.Function<Result<TimeseriesResultValue>,Result<TimeseriesResultValue>> makePreComputeManipulatorFn(TimeseriesQuery query,
                                                                                                                                MetricManipulationFn fn)

Description copied from class: QueryToolChest

Creates a Function that can take in a ResultType and return a new ResultType having applied the MetricManipulatorFn to each of the metrics.

This exists because the QueryToolChest is the only thing that understands the internal serialization format of ResultType, so it's primary responsibility is to "decompose" that structure and apply the given function to all metrics.

This function is called very early in the processing pipeline on the Broker.

Specified by:

makePreComputeManipulatorFn in class QueryToolChest<Result<TimeseriesResultValue>,TimeseriesQuery>

Parameters:

query - The Query that is currently being processed

fn - The function that should be applied to all metrics in the results

Returns:

A function that will apply the provided fn to all metrics in the input ResultType object

makePostComputeManipulatorFn

public com.google.common.base.Function<Result<TimeseriesResultValue>,Result<TimeseriesResultValue>> makePostComputeManipulatorFn(TimeseriesQuery query,
                                                                                                                                 MetricManipulationFn fn)

Description copied from class: QueryToolChest

Generally speaking this is the exact same thing as makePreComputeManipulatorFn. It is leveraged in order to compute PostAggregators on results after they have been completely merged together. To minimize walks of segments, it is recommended to use mergeResults() call instead of this method if possible. However, this may not always be possible as we don’t always want to run PostAggregators and other stuff that happens there when you mergeResults.

Overrides:

makePostComputeManipulatorFn in class QueryToolChest<Result<TimeseriesResultValue>,TimeseriesQuery>

Parameters:

query - The Query that is currently being processed

fn - The function that should be applied to all metrics in the results

Returns:

A function that will apply the provided fn to all metrics in the input ResultType object

resultArraySignature

public RowSignature resultArraySignature(TimeseriesQuery query)

Description copied from class: QueryToolChest

Returns a RowSignature for the arrays returned by QueryToolChest.resultsAsArrays(QueryType, org.apache.druid.java.util.common.guava.Sequence<ResultType>). The returned signature will be the same length as each array returned by QueryToolChest.resultsAsArrays(QueryType, org.apache.druid.java.util.common.guava.Sequence<ResultType>).

Overrides:

resultArraySignature in class QueryToolChest<Result<TimeseriesResultValue>,TimeseriesQuery>

Parameters:

query - same query passed to QueryToolChest.resultsAsArrays(QueryType, org.apache.druid.java.util.common.guava.Sequence<ResultType>)

Returns:

row signature

resultsAsArrays

public Sequence<Object[]> resultsAsArrays(TimeseriesQuery query,
                                          Sequence<Result<TimeseriesResultValue>> resultSequence)

Description copied from class: QueryToolChest

Converts a sequence of this query's ResultType into arrays. The array signature is given by QueryToolChest.resultArraySignature(QueryType). This functionality is useful because it allows higher-level processors to operate on the results of any query in a consistent way. This is useful for the SQL layer and for any algorithm that might operate on the results of an inner query. Not all query types support this method. They will throw UnsupportedOperationException, and they cannot be used by the SQL layer or by generic higher-level algorithms. Some query types return less information after translating their results into arrays, especially in situations where there is no clear way to translate fully rich results into flat arrays. For example, the scan query does not include the segmentId in its array-based results, because it could potentially conflict with a 'segmentId' field in the actual datasource being scanned. It is possible that there will be multiple arrays returned for a single result object. For example, in the topN query, each TopNResultValue will generate a separate array for each of its values. By convention, the array form should include the __time column, if present, as a long (milliseconds since epoch).

Overrides:

resultsAsArrays in class QueryToolChest<Result<TimeseriesResultValue>,TimeseriesQuery>

resultSequence - results of the form returned by QueryToolChest.mergeResults(org.apache.druid.query.QueryRunner<ResultType>)

Returns:

results in array form

resultsAsFrames

public Optional<Sequence<FrameSignaturePair>> resultsAsFrames(TimeseriesQuery query,
                                                              Sequence<Result<TimeseriesResultValue>> resultSequence,
                                                              MemoryAllocatorFactory memoryAllocatorFactory,
                                                              boolean useNestedForUnknownTypes)

This returns a single frame containing the results of the timeseries query

Overrides:

resultsAsFrames in class QueryToolChest<Result<TimeseriesResultValue>,TimeseriesQuery>

Parameters:

query - Query being executed by the toolchest. Used to determine the rowSignature of the Frames

resultSequence - results of the form returned by QueryToolChest.mergeResults(QueryRunner)

useNestedForUnknownTypes - true if the unknown types in the results can be serded using complex types