In order to synchronize the current state of Kubernetes's objects (e.g. pods, containers, etc.),
periodic synch loops are run. When there is a lot of objects to synchronize with,
loops increase communication traffic. At some point when all the traffic interfere cpu usage curve
hits the roof causing 100% cpu utilization.
To distribute the traffic in time, some sync loops can jitter their period in each loop
and help to flatten the curve.
This commit adds JitterUntil function with jitterFactor parameter.
JitterUntil generalizes Until which is a special case for jitterFactor being zero.
Used like:
var pod *api.Pod
err := client.RetryOnConflict(client.DefaultBackoff, func() (err error) {
pod, err = c.Pods("mynamespace").UpdateStatus(update)
return
})
// err may be conflict
Have poller() send to the channel once, immediately, before the ticker
starts. This way, Poll, PollInfinite, and WaitFor will check the
condition immediately, instead of waiting for the poller's interval to
elapse once before doing the initial condition check.
