bucket( ) Query Function

Extends the groupBy( ) function for grouping by time.

This function produces a table, if a graph is a desired, please consider using timeChart instead.

This function divides the search time interval into buckets. Each event is put into a bucket based on its timestamp.

Events are grouped by their bucket, which is a field named _bucket. The value is the buckets start time in milliseconds (UTC time).

The bucket() function takes all the same parameters as groupBy( ). The _bucket is added to the fields grouped by.

Parameters

Name Type Required Default Description
limit number No Defines the maximum number of series to produce (defaults to 50). A warning is produced if this limit is exceeded, unless the parameter is specified explicitly.
timezone string No Defines the time zone for bucketing. This value overrides timeZoneOffsetMinutes which may be passed in the HTTP/JSON query API. For example, timezone=UTC or timezone="+02:00”.
span string No auto Defines the time span for each bucket. The time span is defined as a relative time modifier like 1hour or “3 weeks”. If not provided or set to ‘auto’ the search time interval, and thus the number of buckets, is determined dynamically
buckets number No Defines the number of buckets. The time span is defined by splitting the query time interval into this many buckets. 0..1500
unit [string] No Each value is a unit conversion for the given column. For instance: “bytes/span to Kbytes/day” converts a sum of bytes into Kb/day automatically taking the time span into account. If present, this array must be either length 1 (apply to all series) or have the same length as the function parameter. Default is no conversion. The documentation has a section on this conversion
field [string] No specifies which fields to group by. Note it is possible to group by multiple fields.
function [Aggregate] No count(as=_count) Specifies which aggregate functions to perform on each group. Default is to count the elements in each group.

span is the unnamed parameter.

Examples

Divides the search time interval into buckets. As time span is not specified, the search interval id divided into 127 buckets. Events in each bucket are counted:

bucket(function=count())

Counts different http status codes over time and buckets them into time intervals of 1 minute. Notice we group by two fields status code and the implicit _bucket.

bucket(1min, field=status_code, function=count())

Show response time percentiles over time. Calculate percentiles per minute (bucket time into 1 minute intervals)

bucket(span=60sec, function=percentile(field=responsetime, percentiles=[50, 75, 99, 99.9]))