How to prevent data factory from running out Cosmos DB RU/s

Question

Description

When I copy data from Storage to CosmosDB by Azure data factory, the Cosmos DB RU/s is full and nobody can use it during this time. I want other operations(from Apps) to have higher priority than the operations of ADF.

Database Setting

Here is the setting of our databases.

What have i tried

1. I have tried to lower the performance of ADF, but not work, RU/s of our database is full.

2. I have tried to scale RU/s from 4000 to 12000, but not work.(Maybe I should scale max RU/s up to the more)

Answer 1

There's really no concept of Request Units being "full" - you are able to set how many RU/second a particular container (or database) will support. If you exceed the allocated RU within a given second, Cosmos DB will throttle your operations for a bit.

To avoid this, you can increase your RU/second setting. However, since you mentioned ADF causes your other apps to slow down, be sure to allocate RU/second specifically for the container you are importing data to, not the database itself. However: if you have apps actively querying that same container... then it's right back to my first point: increase RU/Second, especially when Data Factory is running.

There is no way to prioritize operations against a container: all operations are accepted until, within a particular 1-second window, you run out of RU, and then you'll see operations temporarily throttled.