Network latency on MongoDB Atlas at Azure from Azure at same location

MongoDB Atlas
,
1

We are experiencing occasional but significant delays in reading collections with one or very few documents that are also very small.
We are connecting from a .NET Core App Service from Azure Texas to a M30 Atlas cluster in the same region.

The most frequent stack trace ending is:

Server+ServerChannel+<ExecuteProtocolAsync>d__33`1.MoveNextServer+ServerChannel+<ExecuteProtocolAsync>d__33`1.MoveNext Expanded
mongodb.driver.core⭙
CommandWireProtocol`1.ExecuteAsyncCommandWireProtocol`1.ExecuteAsync Expanded
mongodb.driver.core⭙
CommandUsingCommandMessageWireProtocol`1.ExecuteAsyncCommandUsingCommandMessageWireProtocol`1.ExecuteAsync Expanded
mongodb.driver.core⭙
Framework/Library AsyncMethodBuilderCore.StartFramework/Library AsyncMethodBuilderCore.Start Expanded
system.private.corelib.il⭙
CommandUsingCommandMessageWireProtocol`1+<ExecuteAsync>d__19.MoveNextCommandUsingCommandMessageWireProtocol`1+<ExecuteAsync>d__19.MoveNext Expanded
mongodb.driver.core⭙
ExclusiveConnectionPool+AcquiredConnection.ReceiveMessageAsyncExclusiveConnectionPool+AcquiredConnection.ReceiveMessageAsync Expanded
mongodb.driver.core⭙
BinaryConnection.ReceiveMessageAsyncBinaryConnection.ReceiveMessageAsync Expanded
mongodb.driver.core⭙
Framework/Library AsyncMethodBuilderCore.StartFramework/Library AsyncMethodBuilderCore.Start Expanded
system.private.corelib.il⭙
BinaryConnection+<ReceiveMessageAsync>d__57.MoveNextBinaryConnection+<ReceiveMessageAsync>d__57.MoveNext Expanded
mongodb.driver.core⭙
BinaryConnection.ReceiveBufferAsyncBinaryConnection.ReceiveBufferAsync Expanded
mongodb.driver.core⭙
Framework/Library AsyncMethodBuilderCore.StartFramework/Library AsyncMethodBuilderCore.Start Expanded
system.private.corelib.il⭙
BinaryConnection+<ReceiveBufferAsync>d__55.MoveNextBinaryConnection+<ReceiveBufferAsync>d__55.MoveNext Expanded
mongodb.driver.core⭙
BinaryConnection.ReceiveBufferAsyncBinaryConnection.ReceiveBufferAsync Expanded
mongodb.driver.core⭙
Framework/Library AsyncMethodBuilderCore.StartFramework/Library AsyncMethodBuilderCore.Start Expanded
system.private.corelib.il⭙
BinaryConnection+<ReceiveBufferAsync>d__54.MoveNextBinaryConnection+<ReceiveBufferAsync>d__54.MoveNext Expanded
mongodb.driver.core⭙
StreamExtensionMethods.ReadBytesAsyncStreamExtensionMethods.ReadBytesAsync Expanded
mongodb.driver.core⭙
Framework/Library AsyncMethodBuilderCore.StartFramework/Library AsyncMethodBuilderCore.Start Expanded
system.private.corelib.il⭙
StreamExtensionMethods+<ReadBytesAsync>d__4.MoveNextStreamExtensionMethods+<ReadBytesAsync>d__4.MoveNext Expanded
mongodb.driver.core⭙
StreamExtensionMethods.ReadAsyncStreamExtensionMethods.ReadAsync Expanded
mongodb.driver.core⭙
Framework/Library AsyncMethodBuilderCore.StartFramework/Library AsyncMethodBuilderCore.Start Expanded
system.private.corelib.il⭙
StreamExtensionMethods+<ReadAsync>d__1.MoveNextStreamExtensionMethods+<ReadAsync>d__1.MoveNext Expanded
mongodb.driver.core
Framework/Library SslStream.ReadAsyncFramework/Library SslStream.ReadAsync Collapsed
system.net.security.il⭙

-Mongo client is used as singleton (was already used).
-Resources are ok both at App Service and Cluster.

Any suggestion would be welcome.

2

Is it possible you’re opening up a new connection (new auth and TLS handshake) each time? this can take on the order of 100ms and instead you can re-use your connections. Apologies if this isn’t it: double checking low hanging fruit

-Andrew

3

I´m reusing the client.

4

Hi Fabian, are you still experiencing this issue? If so it’s importnat that we get a support case filed: can you do so in the MongoDB Atlas UI?

5

This is probably Azure storage throttling - what storage size are you using?

6

8GB

image
image814×503 31 KB

Currently changing it to 32GB

7

32 won’t help

64Gb gives you 240 IOPS (still peanuts)
128Gb gives you 500 IOPs (something, but not much)
256Gb gives you 1100 IOPS (half of what AWS and GCP start with!!!)

8

if you can migrate to AWS/GCP, MongoDB + Azure has issues, see MongoDB Atlas & Azure - a forced marriage? - DEV Community 👩‍💻👨‍💻

9

I´ll check it out.
Thank you very much Deyan.