when apiserver cache is not ready, the List request with resourceVersion=0 fetch data from the apiserver cache
olderTaoist opened this issue · 5 comments
What would you like to be added?
when apiserver cache is not ready, the List request with resourceVersion=0 fetch data from the apiserver cache, don't directly obtain from etcd.
staging/src/k8s.io/apiserver/pkg/storage/cacher/cacher.go
func (c *Cacher) GetList(ctx context.Context, key string, opts storage.ListOptions, listObj runtime.Object) error {
recursive := opts.Recursive
resourceVersion := opts.ResourceVersion
pred := opts.Predicate
if shouldDelegateList(opts) {
return c.storage.GetList(ctx, key, opts, listObj)
}
listRV, err := c.versioner.ParseResourceVersion(resourceVersion)
if err != nil {
return err
}
if listRV == 0 && !c.ready.check() {
// If Cacher is not yet initialized and we don't require any specific
// minimal resource version, simply forward the request to storage.
return c.storage.GetList(ctx, key, opts, listObj)
}
}
Why is this needed?
In our cluster, the number of some resources like pods are very large(300k+), the number of node is 7k+. the apiserver cache sometime accumulating lag, the kubelet List request of get pod directly obtain from etcd. It consumes lots of cpu & memory that's not expected. i want List request to fetch data from the apiserver cache like ConsistentListFromCache feature gate
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/sig api-machinery
/cc @wojtek-t @serathius