topic Re: Indexer Sizing in Getting Data In

Indexer Sizing

msaleh7422 — Wed, 28 Jan 2026 10:23:12 GMT

We would like your guidance on how to calculate the required number of Splunk indexers for our environment.

Currently, our estimated data ingestion rate is approximately 1 TB per day. We would appreciate it if you could advise on:

The recommended number of indexers needed for this ingestion volume
I Have multi site deployment
#splunk

Re: Indexer Sizing

gcusello — Wed, 28 Jan 2026 13:59:51 GMT

Hi @msaleh7422 ,

a quick and dirty evaluation is:

one indexer every 200 GB/day og ingestion if you haven't a Premium App (ES or ITSI),
one indexer every 100-150 GB/day og ingestion if you have a Premium App (ES or ITSI).

in this second case, in ES training is described to use one indexer every 80 GB/day, but 100-150 GB/day is more correct value.

About CPUs, RAM and storage, you need a Capacity Plan that is very difficoult to do in Community: you need a Splunk Architect from a Splunk Partner.

Ciao.

Giuseppe

Re: Indexer Sizing

PickleRick — Wed, 28 Jan 2026 17:17:17 GMT

This is the kind of question you go to your local friendly Splunk Partner with, not some randoms on the internet.

There are many factors possibly affecting your environment size and overall architecture - search load, retention, HA requirements...

And if someone here tells you "you need 3 indexers" will you run and issue a procurement order based on this? And what if it happens to be undersized? Or the opposite - it will turn out to be mostly idle and you have paid throught the nose for the hardware?