MongoDB composite shard key including timestamp write behavior

Question

I am investigating MongoDB's appropriateness for our use case. We have clients that generate log data, and most of our use cases for this DB involve querying by Client ID and a time range of when the log was generated.

I am aware that using a datetime for a shard key will lead to all writes being sent to a single writer. If we used a composite shard key of client ID + date, is my understanding correct that that will distribute writes across N instances, where N is the number of unique clients?

Answer 1

Yes, that's correct. It would be also beneficial for queries, I assume most of your queries will include Client ID as condition.