APM Data growth rate

[manohar_deepu (Manohar K)]

I have a query about the data size growth in APM as I had heard some concerns on rapid data growth for APM. Can you please answer this for us,

If I have a service with 1k RPS with 6 spans on an average and 5% error rate deployed on 5 boxes, how much data growth can I expect over a day/month if I have sampling rate set to 1 vs data growth if I have sampling rate set to 0?

[axw (Andrew Wilkins)]

It depends a lot on the type of operations, which would influence the size of the events. You can get a rough idea of the document sizes at https://www.elastic.co/guide/en/apm/server/current/sizing-guide.html

A few points to help answer your scenario:

• If you set the sampling rate to 0, then APM will not index any any spans. So with sampling rate of 0 you're eliminating 6000 docs/s.
• Error events are unaffected by sampling; APM will index these regardless of the sampling rate.
• Currently APM indexes a transaction document per request (1K RPS = 1K transaction docs/s), regardless of sampling. We are working on changing the implementation to store pre-aggregated histograms, so you'll have far fewer documents stored.