Splunk Search

Query with Transaction Help/Optimize

zafunt
Explorer

My search is ...

sourcetype=linux_audit (type="SYSCALL" OR type="PATH") | transaction host lin_audit_event maxevents=3 maxspan=24h keepevicted=true | search success="no" (name="/etc/*" OR name="/bin/*" OR name="/usr/sbin/*")
  1. This query is taking a very long time to run, are there any optimizations that I can make?

  2. If a large time range is chosen, the query takes 15+ minutes, and gives me the error that "No matching fields exist". However, if I add host="whateverhost" to the search, I see results. Am I missing some parameters?

Tags (3)
0 Karma
1 Solution

the_wolverine
Champion

The maxspan makes a huge difference. If you can set a lower maxspan, like 1h or even less, it will be significantly faster.

View solution in original post

0 Karma

zafunt
Explorer

Thanks for the suggestion.

now... Please forgive the syntax, I can't copy-paste.

sourcetype=linux_audit (type="SYSCALL" success="no") OR (type="PATH" (name="/etc/" OR name="/bin/" OR name="/usr/sbin*")) | transaction maxevents=3 maxspan=24h keepevicted=true

This seems to be more optimized. However, I am getting the same results. Am, I hitting some kind of limit?

0 Karma

the_wolverine
Champion

The maxspan makes a huge difference. If you can set a lower maxspan, like 1h or even less, it will be significantly faster.

0 Karma

zafunt
Explorer

I've tried the maxspan=5s (even went to 24h). However, my audits look like this in splunk...
3/11/14 8:45:58.171 AM, type=SYSCALL, exe="/usr/bin/rm", uid=1001
3/11/14 8:01:00.000 AM, type=PATH, item=1, name="/etc/shadow"
3/11/14 8:01:00.000 AM, type=PATH, item=0, name="/etc"

These events are created in the audit.log almost instantly, but it looks like the _time is off for the events that are type=PATH.

0 Karma

zafunt
Explorer

I hate to rehash an old thread, but I was able to speed up the query significantly by following the comments from somesoni2 and the_wolverine above. In addition, I was able to create a props.conf file to resolve the timestamp issue mentioned in my last comment.

[source::.../var/log/audit/audit.log(.\d+)?]
TIME_PREFIX = audit(
TIME_FORMAT = %s.%3N

Of course, this would probably be resolved by using rlog.sh in Splunk_TA_Nix app, but it blows up with some older Suse boxes.

0 Karma

somesoni2
Revered Legend

how about moving your second search filters (succes="no"...) to base search filter? This should make the query little faster.

Get Updates on the Splunk Community!

This Week's Community Digest - Splunk Community Happenings [9.26.22]

Get the latest news and updates from the Splunk Community here! Upcoming User Group Events! 👏 Check ...

BSides Splunk 2022 - The Call for Papers is now Open!

TLDR; Main Site: https://bsidessplunk.com CFP Site: https://bsidessplunk.com/cfp CFP Opens: December 15th, ...

Sending Metrics to Splunk Enterprise With the OpenTelemetry Collector

This blog post is part of an ongoing series on OpenTelemetry. The OpenTelemetry project is the second largest ...