[showdeddd]

1. No it would not be expensive. Writing metrics is literally free: https://cloud.google.com/stackdriver/pricing . If metrics didn't exist yet then log 1/1000 requests to control the log volume and find the pattern from the averages.

2. It isn't up to google to tell you if you are querying against the cache or the DB. It's your code. You should know. Just tick something when you use the Redis/BQ/GCS/SQL client.

This task is so easy I would assign it to a junior engineer and expect code changes done in one day!

[invalidname]

1. Logs are not free. Stackdriver was not an option back then.

2. If the phone company charges me extra they tell me which numbers I called. Here a cache miss started happening. Only in production with no tooling available (at the time) to determine why this was happening. A single number of "data read" was all the information given. Not even the table name... That means you end up looking for a needle in a haystack.

I'm guessing you work for Google because your attitude seems similar. No they don't *have* to provide that service which is exactly why they suck. A service oriented company would make the *effort* to provide a user with this information. Especially a paying user at gold level.