Analysis of Firestore reads

Question

Is there currently any way to see where Firestore reads are coming from?

I have several apps and many background + several scheduled cloud functions and it is going to be a big task to try and tune these to reduce reads if I don't know where the reads are coming from.

Even if I could split reads between the front end and the admin SDK that would help narrow things down.

All the SQL databases I have worked with have some kind of profiler to see which queries are being run and how long they take. I wouldn't mind increasing my Firestore usage while I am running the analysis as it would save me usage in the long run.

I am using Angular with AngularFire on the frontend.

EDIT:

One idea I had was to use google analytics to track the reads by using events for each query. I will update this question once I have tried it.

Answer 1

Since this was posted Firestore added audit logging (in late 2021), which allows you to track document reads on the backend and analyze that data using BigQuery.

For example, I could get the document read count per user per day with this query:

SELECT
  JSON_VALUE(proto_payload.audit_log.authentication_info.third_party_principal.payload.user_id) as uid,
  TIMESTAMP_TRUNC(timestamp, DAY) as day,
  SUM(proto_payload.audit_log.num_response_items) as read_count
FROM `nanochat-20241022-mw8qu9.global._Default._AllLogs`
WHERE proto_payload.audit_log.authorization_info[0].permission_type IN ('DATA_READ', 'DATA_WRITE')
  AND proto_payload.audit_log.method_name LIKE 'google.firestore.v1.Firestore%'
GROUP BY 
  JSON_VALUE(proto_payload.audit_log.authentication_info.third_party_principal.payload.user_id), 
  TIMESTAMP_TRUNC(timestamp, DAY)

When charted, that looks like this:

I wrote a post about this with more examples here: Counting document reads per user in Firestore