r/kubernetes • u/Grouchy-Detective394 • 22h ago
Intermittent network output rate drops in pod
Let me set some context. I am running an application on AKS cluster where I have a file in memory that i need to upload to Azure Blob Storage on two different paths.
So I am doing those uploads concurrently.
I am using go, and there are two ABS client created and the upload is done in 2 diff goroutines.
Now what we are seeing is that one upload happens in 1-2 minute, and the other one takes 20mins to finish.
This has occurred enough times that we cant call it intermittent, but still it doesn't happen always.
Upon getting the Blob storage logs, we found that the individual API requests are taking about a minute for the slow upload, while it is taking abt e seconds for the fast one. They confirmed it is a network throughput issue rather than a disk write issue.
We looked at the pod network io metrics ob grafana and saw a drop in output rate during the upload window of the 2nd file.
The drop was from 300KB/s to 30KB/s.
Can someone help me figure out what might cause this to happen?
NOTE: What is consistent in all the instances of this issue is that everytime, there is one file upload that is faster and one is slower.
The same code is doing the upload sith same configurations. The file is same. What is different is the dst file path and the network port.