Automatic merge from submit-queue
Reuse fields and labels
This should significantly reduce memory allocations in apiserver in large cluster.
Explanation:
- every kubelet is refreshing watch every 5-10 minutes (this generally is not causing relist - it just renews watch)
- that means, in 5000-node cluster, we are issuing ~10 watches per second
- since we don't have "watch heartbets", the watch is issued from previously received resourceVersion
- to make some assumption, let's assume pods are evenly spread across pods, and writes for them are evenly spread - that means, that a given kubelet is interested in 1 per 5000 pod changes
- with that assumption, each watch, has to process 2500 (on average) previous watch events
- for each of such even, we are currently computing fields.
This PR is fixing this problem.
golint as of
3390df4df2/lint.go (L1440-L1442)
requires that any function that has a context.Context argument have said
argument in the first position. This commit fixes the one function we had where
it wasn't.
Automatic merge from submit-queue
Move HighWaterMark to the top of the struct in order to fix arm, second time
ref: #33117
Sorry for not fixing everyone at once, but I seriously wasn't prepared for that quick LGTM 😄, so here's the other half.
@lavalamp
> lgtm, but seriously, this is terrible, we probably have this bug all over. And what if someone embeds the etcdWatcher struct in something else not at the top? We need the compiler to enforce things like this, it just can't be done manually. Can you file or link a golang issue for this?
I totally agree! There isn't currently a way of programmatically detecting this unfortunately.
I guess @davecheney or @minux can explain better to you why it's so hard.
This is noted in https://github.com/kubernetes/kubernetes/blob/master/docs/proposals/multi-platform.md as a corner case indeed.
@pwittrock This should be cherrypicked toghether with #33117
Automatic merge from submit-queue
stop etcd watcher when watch chan is closed
When startWatching() stops due to the watch chan is closed, the watcher could still keeps running in the background. When this case happen, we should stop the watcher entirely and close ResultChan() too.
