Goldpinger is too sensitive to autoscaler activity

[dharmab]

Describe the bug

The order of operations for removing a node in Kubernetes is:

1. Cluster autoscaler removes VM from the underlying cloud provider
2. Node object enters NotReady state since the Kubelet process stops reporting
3. Cloud Controller eventually notices that the VM is gone and removes the Node object

The time between 2 and 3 can be quite long (many minutes in some clouds). Goldpinger continuously tries to reach the node during this time causing spikes in Goldpinger metrics.

To Reproduce
Steps to reproduce the behavior:

1. Overscale a cluster in a cloud with long deletion times such as Azure
2. Allow cluster to scale down
3. Observe peer failures in Goldpinger metrics and logs

Expected behavior

Goldpinger should provide a mechanism to filter out NotReady nodes from metric queries to focus on Nodes which are expected to be functioning normally.

Screenshots

Here's an example showing Goldpinger error rates spike as a cluster scaled down over a period of hours.

Environment (please complete the following information):

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Additional context
Add any other context about the problem here.

[dharmab]

Here's another case- a cluster had an autoscaler mass scale in event, which caused goldpinger to incorrectly report 23% of the network was failing.

[dntosas]

Hello people!

We have the same issue ^^ but filtering out a node because of status NotReady is not correct as there are cases where node instead of being marked as NotReady because of scale-down, could be labeled NotReady as legitimately corrupted.

So we better focus on filtering out nodes on different label/attribute like SchedulingDisabled or smth. What do you think?

[danV111]

Hello!

Any updates on this one?

[rbtr]

#107 should help - after the node eviction timeout, pods go to terminating state and goldpinger will stop trying to reach them

[danV111]

@rbtr thank you. I will give it a go and come back with some feedback in the next days.