[Filebeat] CPU consumption spikes, when using filebeat with k8s autodiscovery.

[Evgenikk]

We run filebeat as a daemonset in Kubernetes clusters to send logs to Kafka. Seems like sometimes filebeat restarts all harvesters, which leads to CPU usage spikes. We noticed this problem after this changes.

In our case, we've fixed it by removing this block of code, but it is not the proper solution and can't be used in the upstream.

In this graph, you may see CPU consumption of filebeats before and after our "fix":

• Version: filebeat-oss:8.7.1
• Operating System: Ubuntu 20.04.5 LTS (GNU/Linux 5.15.0-1033-aws aarch64),
• Kubernetes version: AWS EKS 1.21

[botelastic]

This issue doesn't have a Team:<team> label.

[botelastic]

Hi!
We just realized that we haven't looked into this issue in a while. We're sorry!

We're labeling this issue as Stale to make it hit our filters and make sure we get back to it as soon as possible. In the meantime, it'd be extremely helpful if you could take a look at it as well and confirm its relevance. A simple comment with a nice emoji will be enough :+1.
Thank you for your contribution!