MS 图表日历 API | 订阅用户日历 | 并行创建 100 个或更多会议时缺少 50% 的会议通知

Question

I am using MS Graph API to subscribe users calendar for meeting notifications. There is no issue with few meetings for multiple users but when we run our load test with 100 meetings then there were lots of missing booking notifications.

For better understanding, I m adding a few steps to verify:

1. Deploy an Event Hub for exchange notifications as per Microsoft Document . I have tried both Event Hub and an azure function for verification.
2. Subscribe user calendar with the above URL as notification URL using Graph Subscription API POST .
3. Run 100 meeting load test where we are creating an outlook meeting from graph API on the subscribed user calendar.

I have run a different load with 2 users and the result is below:

So my question is that, is there any kind of limitation in Graph Notification or any other issue!

Answer 1

You are experiencing throttling. According to Graph throttling guide for Outlook service , you can have up to 4 concurrent requested per user calendar. a large number of your requests are throttled, thus no events are created - no change notifications..

My recommendation:

1. Read through the throttling guide here then
2. Run your load test with out reaching Graph because Graph will handle your load in production with reasonable throttling mechanism.
3. Run your load test using different user calendars such that the matrix is within the acceptable load on Graph