I have setup CPU and Memory Requests=Limits on all containers of my pod in order to qualify it for Guaranteed Quality of Service class. Now, look at these CPU Usage and CPU Throttling graphs for same Pod for last 6 hours.
Does this look normal and expected?
CPU Usage has not even touched 50% of the set limit a single time and still it was being throttled upto 58% at times.
And a side question, what does that red line at 25% in the Throttling graph indicates?
I did some research on this topic and found that there was a bug in Linux kernel that could have caused this and that it was fixed in version 4.18 of the kernel. Reference: this and this
We are on GKE running Container Optimized OS by Google. I checked the linux kernel version on our nodes and they are on 4.19.112+ so I guess we already have that patch? What else could be the reason of this throttling pattern?
P.S. This pod (actually a deployment with autoscaling) is deployed on a separate Node pool which has none of our other workloads running on it. So the only pods other than this deployment running on Nodes in this node pool are some metrics and logging agents and exporters. Here is the full list of pods running on the same Node at which the pod discussed above is scheduled. There are indeed some pods that don't have any CPU limits set on them. Do I need to somehow set CPU limits on these as well?
