How to lower resource consumption on startup

[portly-halicore-76]

Hi,

I can't find this question in the docs, hopefully one can give me any pointers. When a new replica, most often after updating the operator, has been deployed to a cluster, it will first go over each resource it is responsible for. After that, the replica will go on reconciling on changes etc. However, this way of working results in a spike of resource consumption (CPU / MEMORY) just after startup. Later on it will throttle down and be less resource intensive.

My question is as follows, is rate-limiting, probably through the controller options, a way to prevent this spike? If so, how? If not, how do others deal with these scenarios?

Kind regards

[camilamacedo86]

I think you need to do something like

lim := workqueue.NewMaxOfRateLimiter(
  workqueue.NewItemExponentialFailureRateLimiter(15*time.Second, 100*time.Second),
  workqueue.NewBucketRateLimiter(10, 100),
)

ctrl.NewControllerManagedBy(mgr).
  For(&myv1.MyKind{}).
  WithOptions(controller.Options{
    RateLimiter:             lim,
    MaxConcurrentReconciles: 1,
  }).
  Complete(myReconciler)

Give a look at: https://github.com/search?q=repo%3Akubernetes-sigs%2Fcontroller-runtime+RateLimiter&type=code

I hope that helps out