Splunk Search

How do I get Splunk to extract nested JSON arrays properly?

lyndac
Contributor

I am indexing JSON data. I need to be able to do stats based "by patches" and "by admin". I can't get spath or mvexpand to extract the nested arrays properly. Can anyone help me to figure this out?

My props.conf looks like this:

[ my_json ]
INDEXED_EXTRACTIONS = json
KV_MODE=none
MAX_TIMESTAMP_LOOKAHEAD=30
NO_BINARY_CHECK=true
TIMESTAMP_FIELDS=upTime
TIME_FORMAT=%Y-%m-%d %H:%M:%S

The data is similar to this:

{
  "upTime": "2015-02-08 16:43:23",
  "type": "thetype",
   "id": "123454829",
   "systems": [
      {
          "hostname": "host1",
          "admins": [ "jdoe","lcod", "pamtie"],
          "os": "linux",
          "patches": ["1.2", "2.3", "4.3", "5.4"]
      },
      {
          "hostname": "host2",
          "admins": [ "barry", "patty"],
          "os": "linux",
          "patches": ["2.3", "5.4"]
      }
  ]
}
1 Solution

lyndac
Contributor

Thanks for your help. I was finally able to accomplish this using spath & mvexpand. In case someone else needs this in the future, my search is now:

index=foo | spath path=systems{} output=x | fields - _raw | fields upTime, type, id, x | mvexpand x | spath input=x | rename admins{} as admins | mvexpand admins | stats count as Count by type, admins

View solution in original post

lyndac
Contributor

Thanks for your help. I was finally able to accomplish this using spath & mvexpand. In case someone else needs this in the future, my search is now:

index=foo | spath path=systems{} output=x | fields - _raw | fields upTime, type, id, x | mvexpand x | spath input=x | rename admins{} as admins | mvexpand admins | stats count as Count by type, admins

somesoni2
Revered Legend

Your sample data doesn't look like in proper json format (some keys are not in double quotes) and that should be the reason spath (in search) and INDEXED_EXTRACTIONS = json in props.conf is not recognizing array. Check the syntax here http://pro.jsonlint.com/

0 Karma

bmacias84
Champion

This kind of data is a pain to work with because it requires the uses of mv commands. to extract what you want you need first zip the data you want to pull out.

…| rename systems{}.hostname as hostname, rename systems{}.patches as patches | eval a mvzip(hostname,patches, "|") | fields _time a | mvexpand a | rex field=a "(?<hostname>[^\|]+)\|(?<patches>[^\|]+)"

If you need to expand patches just append mvexpand patches to the end.

I use this method to to extract multilevel deep fields with multiple values. It does a the limitation of only able to extract two multi valued fields from the data and get very slow with large data sets.

Get Updates on the Splunk Community!

Splunk Observability Cloud’s AI Assistant in Action Series: Analyzing and ...

This is the second post in our Splunk Observability Cloud’s AI Assistant in Action series, in which we look at ...

Elevate Your Organization with Splunk’s Next Platform Evolution

 Thursday, July 10, 2025  |  11AM PDT / 2PM EDT Whether you're managing complex deployments or looking to ...

Splunk Answers Content Calendar, June Edition

Get ready for this week’s post dedicated to Splunk Dashboards! We're celebrating the power of community by ...