com.netflix.spectator.atlas.impl

Interface DataExpr

All Known Subinterfaces:

DataExpr.AggregateFunction

All Known Implementing Classes:

DataExpr.All, DataExpr.Count, DataExpr.DropRollup, DataExpr.GroupBy, DataExpr.KeepRollup, DataExpr.Max, DataExpr.Min, DataExpr.Sum

public interface DataExpr

Data expressions for defining how to aggregate values. For more information see: https://github.com/Netflix/atlas/wiki/Reference-data Classes in this package are only intended for use internally within spectator. They may change at any time and without notice.

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static interface	DataExpr.AggregateFunction Base type for simple aggregate functions.
static interface	DataExpr.Aggregator Helper for incrementally computing an aggregate of a set of tag values.
static class	DataExpr.All Includes all datapoints that match the query expression.
static class	DataExpr.Count Aggregates all datapoints that match the query to a single datapoint that is the number of input values.
static class	DataExpr.DropRollup Rollup inputs by dropping the specified keys.
static class	DataExpr.GroupBy Compute a set of time series matching the query and grouped by the specified keys.
static class	DataExpr.KeepRollup Rollup inputs by only keeping the specified keys.
static class	DataExpr.Max Aggregates all datapoints that match the query to a single datapoint that is the maximum of the input values.
static class	DataExpr.Min Aggregates all datapoints that match the query to a single datapoint that is the minimum of the input values.
static class	DataExpr.Sum Aggregates all datapoints that match the query to a single datapoint that is the sum of the input values.

Method Summary

Modifier and Type	Method and Description
default DataExpr.Aggregator	aggregator() Get an aggregator using the default set of tags for the final result.
DataExpr.Aggregator	aggregator(java.util.Map<java.lang.String,java.lang.String> tags) Get an aggregator that can be incrementally fed values.
default java.lang.Iterable<TagsValuePair>	eval(java.lang.Iterable<TagsValuePair> input) Evaluate the data expression over the input.
Query	query() Query for selecting the input measurements that should be aggregated.

Method Detail

query

Query query()

Query for selecting the input measurements that should be aggregated.

aggregator

DataExpr.Aggregator aggregator(java.util.Map<java.lang.String,java.lang.String> tags)

Get an aggregator that can be incrementally fed values. See eval(Iterable) if you already have the completed list of values.

Parameters:

tags - The set of tags for the final aggregate.

Returns:

Aggregator for this data expression.

aggregator

default DataExpr.Aggregator aggregator()

Get an aggregator using the default set of tags for the final result. The tags will be extracted based on the exact matches for the underlying query.

eval

default java.lang.Iterable<TagsValuePair> eval(java.lang.Iterable<TagsValuePair> input)

Evaluate the data expression over the input.

Parameters:

input - Set of data values. The data will get filtered based on the query, that does not need to be done in advance.

Returns:

Aggregated data values.