AWS Lambda Invocations Trigger MongoDB Connection Spikes

[alexbevi (Alex Bevilacqua)]

Continuing the discussion from AWS Lambda Invocations Trigger MongoDB Connection Spikes:

@Alparslan_Ozkan

Despite following this pattern, we are still observing a very high number of concurrent connections (3–4.5K) at peak times. We are trying to understand why connections aren’t being fully reused or cleaned up as expected.

Would you have insights into why thousands of connections still accumulate even with the recommended global scope pattern?

Without knowing more about the workload itself and how many concurrent requests are in flight it’s difficult to answer this question. I wrote about how many connections MongoDB drivers may establish at How Many Connections is My Application Establishing to My MongoDB Cluster? | ALEX BEVILACQUA, which might provide some insight as there will always be at least 3 connections per Lambda instance to service a database operation (1 for the operation, 1 monitoring connection and 1 RTT connection)