Splunk Search

splunk search language

Path Finder

Hi guys...

I have been working on a few splunk apps during the last 6 months... in that time i have ran into a peculiar problem a couple of times... the problem being the folowing:

when i use a search like:

index="index" sourcetype="sourcertype" field1="*" field2="*"

I expect all the results because i am not filtering anything... but instead i get only a small fraction of the indexed logs...

when i use the same search only writted differently like so:

index="index" sourcetype="sourcertype" NOT (field1!="*" field2!="*")

I get all the indexed data as expected...

Has anyone else ran into this or is it just me?

and

Has anyone found a solution to this besides rewriting the search to say the exactly the same thing...

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2 Solutions

Influencer
field1="*"

will filter and return all events where field1 is present.

View solution in original post

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Splunk Employee
Splunk Employee

Exactly, and so you might ask why your second search works. Well, here's why:

field=* returns all events that have a value in that field; i.e. NOT NULL

So, you might expect that field!=* would return all events where there is not a value in the specified field i.e. NULL. But, that is not the case.

The way to search for NULL values is with:
NOT field=*

Go ahead and test a search with field!=* and you will get 0 matching results. This appears to be an exception to where NOT and ! do not return the same results. Or, I'm not understanding the difference clearly enough.

So, in your example your field=* term was in fact filtering out events. Specifically those that don't have a value in the specified field. (You might want to investigate why that is the case if it is not what you are expecting).

In your second example when you negate field!=* (which returns 0 results) with NOT field!=* you get all results.

It seems like in your example you just need to use index="index" and sourcetype="sourcetype"

I hope this helps.

View solution in original post

0 Karma

Splunk Employee
Splunk Employee

Exactly, and so you might ask why your second search works. Well, here's why:

field=* returns all events that have a value in that field; i.e. NOT NULL

So, you might expect that field!=* would return all events where there is not a value in the specified field i.e. NULL. But, that is not the case.

The way to search for NULL values is with:
NOT field=*

Go ahead and test a search with field!=* and you will get 0 matching results. This appears to be an exception to where NOT and ! do not return the same results. Or, I'm not understanding the difference clearly enough.

So, in your example your field=* term was in fact filtering out events. Specifically those that don't have a value in the specified field. (You might want to investigate why that is the case if it is not what you are expecting).

In your second example when you negate field!=* (which returns 0 results) with NOT field!=* you get all results.

It seems like in your example you just need to use index="index" and sourcetype="sourcetype"

I hope this helps.

View solution in original post

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Communicator

I am running into the same problem, can you share the eval command you ran to write NULL in the empty fields?

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Path Finder

Thank you also for the quick answer...

i can't just use index and sourcetype because i run postprocess searches on the results and i get nothing unless i specify the fields=*...

using the NOT != is a bit messy...

i resolved my issue by using eval to write "NULL" into the empty fields.

Again thanks for the help.

0 Karma

Influencer
field1="*"

will filter and return all events where field1 is present.

View solution in original post

0 Karma

Path Finder

Thanks for the quick answer.

0 Karma