Expands the values of a multivalue field into separate events, one event for each value in the multivalue field. For each result, the
mvexpand command creates a new result for every multivalue field.
mvexpand <field> [limit=<int>]
- Syntax: <field>
- Description: The name of a multivalue field.
- Syntax: limit=<int>
- Description: Specify the number of values of <field> to use for each input event.
- Default: 0, or no limit
A limit exists on the amount of RAM that the
mvexpand command is permitted to use while expanding a batch of results. By default the limit is 500MB. The input chunk of results is typically
maxresults or smaller in size, and the expansion of all these results resides in memory at one time. The total necessary memory is the average result size multiplied by the number of results in the chunk multiplied by the average size of the multivalue field being expanded.
If this attempt exceeds the configured maximum on any chunk, the chunk is truncated and a warning message is emitted. If you have Splunk Enterprise, you can adjust the limit by editing the
max_mem_usage_mb setting in the
limits.conf file. If you have Splunk Cloud and encounter problems because of this limit, file a Support ticket.
Create new events for each value of multivalue field, "foo".
... | mvexpand foo
Create new events for the first 100 values of multivalue field, "foo".
... | mvexpand foo limit=100
mvexpand command only works on one multivalue field. This example walks through how to expand an event with more than one multivalue field into individual events for each field value. For example, given these events, with sourcetype=data:
2012-10-01 00:11:23 a=22 b=21 a=23 b=32 a=51 b=24 2012-10-01 00:11:22 a=1 b=2 a=2 b=3 a=5 b=2
sourcetype=data | rex field=_raw "a=(?<a>\d+)" max_match=5 | rex field=_raw "b=(?<b>\d+)" max_match=5 | eval fields = mvzip(a,b) | table _time fields
Use the mvexpand command and the rex command on the new field, fields, to create new events and extract the fields alpha and beta:
sourcetype=data | rex field=_raw "a=(?<a>\d+)" max_match=5 | rex field=_raw "b=(?<b>\d+)" max_match=5 | eval fields = mvzip(a,b) | mvexpand fields | rex field=fields "(?<alpha>\d+),(?<beta>\d+)" | table _time alpha beta
Use the table command to display only the _time, alpha, and beta fields in a results table:
(Thanks to Splunk user Duncan for this example. You can see another version of this with JSON data and the spath command.)
Have questions? Visit Splunk Answers and see what questions and answers the Splunk community has using the mvexpand command.
This documentation applies to the following versions of Splunk Cloud™: 6.6.3