- Move from the old github.com/golang/glog to k8s.io/klog
- klog as explicit InitFlags() so we add them as necessary
- we update the other repositories that we vendor that made a similar
change from glog to klog
* github.com/kubernetes/repo-infra
* k8s.io/gengo/
* k8s.io/kube-openapi/
* github.com/google/cadvisor
- Entirely remove all references to glog
- Fix some tests by explicit InitFlags in their init() methods
Change-Id: I92db545ff36fcec83afe98f550c9e630098b3135
the caching layer on endpoint is redundant.
Here are the 3 related objects in picture:
devicemanager <-> endpoint <-> plugin
Plugin is the source of truth for devices
and device health status.
devicemanager maintain healthyDevices,
unhealthyDevices, allocatedDevices based on updates
from plugin.
So there is no point for endpoint caching devices,
this patch is removing this caching layer on endpoint,
Also removing the Manager.Devices() since i didn't
find any caller of this other than test, i am adding a
notification channel to facilitate testing,
If we need to get all devices from manager in future,
it just need to return healthyDevices + unhealthyDevices,
we don't have to call endpoint after all.
This patch makes code more readable, data model been simplified.
There is a race in predicateAdmitHandler Admit() that getNodeAnyWayFunc()
could get Node with non-zero deviceplugin resource allocatable for a
non-existing endpoint. That race can happen when a device plugin fails,
but is more likely when kubelet restarts as with the current registration
model, there is a time gap between kubelet restart and device plugin
re-registration. During this time window, even though devicemanager could
have removed the resource initially during GetCapacity() call, Kubelet
may overwrite the device plugin resource capacity/allocatable with the
old value when node update from the API server comes in later. This
could cause a pod to be started without proper device runtime config set.
To solve this problem, introduce endpointStopGracePeriod. When a device
plugin fails, don't immediately remove the endpoint but set stopTime in
its endpoint. During kubelet restart, create endpoints with stopTime set
for any checkpointed registered resource. The endpoint is considered to be
in stopGracePeriod if its stoptime is set. This allows us to track what
resources should be handled by devicemanager during the time gap.
When an endpoint's stopGracePeriod expires, we remove the endpoint and
its resource. This allows the resource to be exported through other channels
(e.g., by directly updating node status through API server) if there is such
use case. Currently endpointStopGracePeriod is set as 5 minutes.
Given that an endpoint is no longer immediately removed upon disconnection,
mark all its devices unhealthy so that we can signal the resource allocatable
change to the scheduler to avoid scheduling more pods to the node.
When a device plugin endpoint is in stopGracePeriod, pods requesting the
corresponding resource will fail admission handler.
incompatible changes:
- Add GetDevicePluginOptions rpc call. This is needed when we switch
from Registration service to probe-based plugin watcher.
- Change AllocateRequest and AllocateResponse to allow device requests
from multiple containers in a pod. Currently only made mechanical
change on the devicemanager and test code to cope with the API but
still issues an Allocate call per container. We can modify the
devicemanager in 1.11 to issue a single Allocate call per pod.
The change will also facilitate incremental API change to communicate
pod level information through Allocate rpc if there is such future
need.
