Instead of using two metrics use just one metrics with multiple labels,
since the labels can only get 2 values, 200 or 503 there is no risk of
carindality explosion and are simple to represent in graphs.
Change-Id: I0e9cbd6ec2051de44d277d673dc20f02b96aa4d1
TL;DR: we want to start failing the LB HC if a node is tainted with ToBeDeletedByClusterAutoscaler.
This field might need refinement, but currently is deemed our best way of understanding if
a node is about to get deleted. We want to do this only for eTP:Cluster services.
The goal is to connection draining terminating nodes
- add new header "X-Load-Balancing-Endpoint-Weight" returned from service health. Value of the header is number of local endpoints. Header can be used in weighted load balancing. Parsing header for number of endpoints is faster than unmarshalling json from the content body.
- add missing unit test for new and old headers returned from service health
Both proxies handle IPv4 and IPv6 nodeport addresses separately, but
GetNodeAddresses went out of its way to make that difficult. Fix that.
This commit does not change any externally-visible semantics, but it
makes the existing weird semantics more obvious. Specifically, if you
say "--nodeport-addresses 10.0.0.0/8,192.168.0.0/16", then the
dual-stack proxy code would have split that into a list of IPv4 CIDRs
(["10.0.0.0/8", "192.168.0.0/16"]) to pass to the IPv4 proxier, and a
list of IPv6 CIDRs ([]) to pass to the IPv6 proxier, and then the IPv6
proxier would say "well since the list of nodeport addresses is empty,
I'll listen on all IPv6 addresses", which probably isn't what you
meant, but that's what it did.
Today, the health check response to the load balancers asking Kube-proxy for
the status of ETP:Local services does not include the healthz state of Kube-
proxy. This means that Kube-proxy might indicate to load balancers that they
should forward traffic to the node in question, simply because the endpoint
is running on the node - this overlooks the fact that Kube-proxy might be
not-healthy and hasn't successfully written the rules enabling traffic to
reach the endpoint.
Server.Serve() always returns a non-nil error. If it exits because the
http server is closed, it will return ErrServerClosed. To differentiate
the error, this patch changes to close the http server instead of the
listener when the Service is deleted. Closing http server automatically
closes the listener, there is no need to cache the listeners any more.
Signed-off-by: Quan Tian <qtian@vmware.com>
The proxy healthz server assumed that kube-proxy would regularly call
UpdateTimestamp() even when nothing changed, but that's no longer
true. Fix it to only report unhealthiness when updates have been
received from the apiserver but not promptly pushed out to
iptables/ipvs.
Kube-proxy runs two different health servers; one for monitoring the
health of kube-proxy itself, and one for monitoring the health of
specific services. Rename them to "ProxierHealthServer" and
"ServiceHealthServer" to make this clearer, and do a bit of API
cleanup too.
The existing healthcheck lib was pretty complicated and was hiding some
bugs (like the count always being 1), This is a reboot of the interface
and implementation to be significantly simpler and better tested.
