During scheduler_perf testing, roughly 10% of the PodSchedulingContext update
operations failed with a conflict error. Using SSA would avoid that, but
performance measurements showed that this causes a considerable
slowdown (primarily because of the slower encoding with JSON instead of
protobuf, but also because server-side processing is more expensive).
Therefore a normal update is tried first and SSA only gets used when there has
been a conflict. Using SSA in that case instead of giving up outright is better
because it avoids another scheduling attempt.
PVC and containers shared the same ResourceRequirements struct to define their
API. When resource claims were added, that struct got extended, which
accidentally also changed the PVC API. To avoid such a mistake from happening
again, PVC now uses its own VolumeResourceRequirements struct.
The `Claims` field gets removed because risk of breaking someone is low:
theoretically, YAML files which have a claims field for volumes now
get rejected when validating against the OpenAPI. Such files
have never made sense and should be fixed.
Code that uses the struct definitions needs to be updated.
using wait.PollUntilContextTimeout instead of deprecated wait.Poll for test/integration/scheduler
using wait.PollUntilContextTimeout instead of deprecated wait.Poll for test/e2e/scheduling
using wait.ConditionWithContextFunc for PodScheduled/PodIsGettingEvicted/PodScheduledIn/PodUnschedulable/PodSchedulingError
* feature(sscheduling_queue): track events per Pods
* fix typos
* record events in one slice and make each in-flight Pod to refer it
* fix: use Pop() in test before AddUnschedulableIfNotPresent to register in-flight Pods
* eliminate MakeNextPodFuncs
* call Done inside the scheduling queue
* fix comment
* implement done() not to require lock in it
* fix UTs
* improve the receivedEvents implementation based on suggestions
* call DonePod when we don't call AddUnschedulableIfNotPresent
* fix UT
* use queuehint to filter out events for in-flight Pods
* fix based on suggestion from aldo
* fix based on suggestion from Wei
* rename lastEventBefore → previousEvent
* fix based on suggestion
* address comments from aldo
* fix based on the suggestion from Abdullah
* gate in-flight Pods logic by the SchedulingQueueHints feature gate
We only added failed plulgins, but actually this will not work unless
we make the status with a fitError because we only copy the failured plugins
to podInfo if it is a fitError
Signed-off-by: kerthcet <kerthcet@gmail.com>
The plugins get called by scheduler goroutines. At least the polling seems to
be done concurrently and thus needs locking.
Locking the PreBindPlugin state is less obvious. It might be that the scheduler
is really done with the test pod, but that ordering doesn't seem to be enough
for the race detector. It's simpler to add mutex locking.
This touches cases where FromInt() is used on numeric constants, or
values which are already int32s, or int variables which are defined
close by and can be changed to int32s with little impact.
Signed-off-by: Stephen Kitt <skitt@redhat.com>
PVCs using the ReadWriteOncePod access mode can only be referenced by a
single pod. When a pod is scheduled that uses a ReadWriteOncePod PVC,
return "Unschedulable" if the PVC is already in-use in the cluster.
To support preemption, the "VolumeRestrictions" scheduler plugin
computes cycle state during the PreFilter phase. This cycle state
contains the number of references to the ReadWriteOncePod PVCs used by
the pod-to-be-scheduled.
During scheduler simulation (AddPod and RemovePod), we add and remove
reference counts from the cycle state if they use any of these
ReadWriteOncePod PVCs.
In the Filter phase, the scheduler checks if there are any PVC reference
conflicts, and returns "Unschedulable" if there is a conflict.
This is a required feature for the ReadWriteOncePod beta. See for more context:
https://github.com/kubernetes/enhancements/tree/master/keps/sig-storage/2485-read-write-once-pod-pv-access-mode#beta
