In case of node reboot/kubelet restart, the flow of events involves
obtaining the state from the checkpoint file followed by setting
the `healthDevices`/`unhealthyDevices` to its zero value. This is
done to allow the device plugin to re-register itself so that
capacity can be updated appropriately.
During the allocation phase, we need to check if the resources requested
by the pod have been registered AND healthy devices are present on
the node to be allocated.
Also we need to move this check above `needed==0` where needed is
required - devices allocated to the container (which is obtained from
the checkpoint file) because even in cases where no additional devices
have to be allocated (as they were pre-allocated), we still need to
make sure he devices that were previously allocated are healthy.
Signed-off-by: Swati Sehgal <swsehgal@redhat.com>
Currently, there are some unit tests that are failing on Windows due to
various reasons:
- paths not properly joined (filepath.Join should be used).
- Proxy Mode IPVS not supported on Windows.
- DeadlineExceeded can occur when trying to read data from an UDP
socket. This can be used to detect whether the port was closed or not.
- In Windows, with long file name support enabled, file names can have
up to 32,767 characters. In this case, the error
windows.ERROR_FILENAME_EXCED_RANGE will be encountered instead.
- files not closed, which means that they cannot be removed / renamed.
- time.Now() is not as precise on Windows, which means that 2
consecutive calls may return the same timestamp.
- path.Base() will return the same path. filepath.Base() should be used
instead.
- path.Join() will always join the paths with a / instead of the OS
specific separator. filepath.Join() should be used instead.
The commit a8b8995ef2
changed the content of the data kubelet writes in the checkpoint.
Unfortunately, the checkpoint restore code was not updated,
so if we upgrade kubelet from pre-1.20 to 1.20+, the
device manager cannot anymore restore its state correctly.
The only trace of this misbehaviour is this line in the
kubelet logs:
```
W0615 07:31:49.744770 4852 manager.go:244] Continue after failing to read checkpoint file. Device allocation info may NOT be up-to-date. Err: json: cannot unmarshal array into Go struct field PodDevicesEntry.Data.PodDeviceEntries.DeviceIDs of type checkpoint.DevicesPerNUMA
```
If we hit this bug, the device allocation info is
indeed NOT up-to-date up until the device plugins register
themselves again. This can take up to few minutes, depending
on the specific device plugin.
While the device manager state is inconsistent:
1. the kubelet will NOT update the device availability to zero, so
the scheduler will send pods towards the inconsistent kubelet.
2. at pod admission time, the device manager allocation will not
trigger, so pods will be admitted without devices actually
being allocated to them.
To fix these issues, we add support to the device manager to
read pre-1.20 checkpoint data. We retroactively call this
format "v1".
Signed-off-by: Francesco Romani <fromani@redhat.com>
The GetAllocatableDevices, needed to support the podresources
API, doesn't take into account the device health when computing
its output.
In this PR we address this gap and add unit tests along the way
to prevent regressions. This gives us a good initial coverage,
E2E tests to cover this case are much harder to write, because
we would need to inject faults to trigger the unhealthy status.
We will evaluate if adding these tests into later PRs.
Signed-off-by: Francesco Romani <fromani@redhat.com>
If device plugin returns device without topology, keep it internaly
as NUMA node -1, it helps at podresources level to not export NUMA
topology, otherwise topology is exported with NUMA node id 0,
which is not accurate.
It's imposible to unveile this bug just by tracing json.Marshal(resp)
in podresource client, because NUMANodes field ID has json property
omitempty, in this case when ID=0 shown as emtpy NUMANode.
To reproduce it, better to iterate on devices and just
trace dev.Topology.Nodes[0].ID.
Signed-off-by: Alexey Perevalov <alexey.perevalov@huawei.com>
suppose there are two devices dev1 and dev2, each has NUMA Nodes associated as below:
dev1: numa1
dev2: numa1, numa2
and we request a device from numa2, currently filterByAffinity() will return
[], [dev1, dev2], [] if loop of available devices produce a sequence of [dev1, dev2],
that is is not desirable as what we truely expect is an allocation of dev2 from numa2.
We want to make the return type of the GetDevices() method of the
podresources DevicesProvider interface consistent with
the newly added GetAllocatableDevices type.
This makes the code easier to read and reduces the coupling between
the podresourcesapi server and the devicemanager code.
No intended changes in behaviour, but the different return types
now requires some data massaging. Tests are updated accordingly.
Signed-off-by: Francesco Romani <fromani@redhat.com>
Device plugin which implements v1beta interface can return nil in
Topology field
For example nvidia-gpu-deviceplugin
3520254b75/nvidia.go (L147)
Signed-off-by: Alexey Perevalov <alexey.perevalov@huawei.com>
It covers deviceplugin & cpumanager.
It has drawback, since cpuset and all other structs including cadvisor's keep
cpu as int, but for protobuf based interface is better to have fixed
int.
This patch also introduces additional interface CPUsProvider, while
DeviceProvider might have been extended too.
Checkpoint not covered by unit test.
Signed-off-by: Swati Sehgal <swsehgal@redhat.com>
Signed-off-by: Alexey Perevalov <alexey.perevalov@huawei.com>
- allocatePodResources logic altered to allow for container by container
device allocation.
- New type PodReusableDevices
- New field in devicemanager devicesToReuse
Instead of having a single call for Allocate(), we now split this into two
functions Allocate() and UpdatePluginResources().
The semantics split across them:
// Allocate configures and assigns devices to a pod. From the requested
// device resources, Allocate will communicate with the owning device
// plugin to allow setup procedures to take place, and for the device
// plugin to provide runtime settings to use the device (environment
// variables, mount points and device files).
Allocate(pod *v1.Pod) error
// UpdatePluginResources updates node resources based on devices already
// allocated to pods. The node object is provided for the device manager to
// update the node capacity to reflect the currently available devices.
UpdatePluginResources(
node *schedulernodeinfo.NodeInfo,
attrs *lifecycle.PodAdmitAttributes) error
As we move to a model in which the TopologyManager is able to ensure
aligned allocations from the CPUManager, devicemanger, and any
other TopologManager HintProviders in the same synchronous loop, we will
need to be able to call Allocate() independently from an
UpdatePluginResources(). This commit makes that possible.
