New anti-windup technique: use the request arrival time as the floor
on the virtual dispatch time. Prevent bound violations where they
might arise rather than fixing up just one queue at dispatch time,
so that the fixed up dispatch times figure into the dispatching choice.
Two tweaks to the shuffle sharding. Take seats of executing requests
into account as well as seats of waiting requests. Do not always
consider the generated hand in the same order.
Rename the queueset methods that do shuffle sharding and finding the
queue to dispatch from, because the old names were confusingly
similar.
Tighten up some request margins.
Name the test cases in TestNoRestraint and TestWindup.
Kubernetes-commit: 4b9cba85874158b25b5c994773a4ec04343820c2
Canonicalize listing of test cases.
Make TestNoRestraint try both cases: competition and none.
Kubernetes-commit: 0ee1a7b4ff9012b050bd447055ad5e1e8c57c30e
Make TestNoRestraint verify that fairness is NOT achieved
when there is real competition.
Make TestWindup run two cases, to show that 0.1 is too narrow
a margin and 0.26 is wide enough.
Kubernetes-commit: c4945fdf0c14ba2032a5c8edf192678d9fe00374
These behavioral unit tests of queueset were failing because the
evaluation criteria were too strict.
Kubernetes-commit: 59d319ec06bb33289a87036418b4a61ed3bb215f
So that the width estimate has some effect but not a grossly excessive
one.
Added the fifo::Peek method to simplify the fifo client code.
Also renamed the queueSet::estimatedServiceTime field to
estimatedServiceSeconds to make the units clear.
Kubernetes-commit: a0c161f2f6908ee424ea888ff40f75ff071bd20a
Instead of a plain `Mutex`, use an `RWMutex` so that the common
operations can proceed in parallel.
Kubernetes-commit: 58927c1abede11ce7a8a74104328cf823df1b39e
The cmp comparison is relatively expensive (#104821). If we're not
going to log it, we shouldn't make the comparison.
Kubernetes-commit: f9f556dc7061df1dfc8c1628db983eeb97149317
Now tries a little harder to get to meaningful stack frames.
This revision seems to strike a balance that is useful in the queueset tests.
Kubernetes-commit: b56dd725032cb7a14aa27e4c50c1c9d7c6d23eb1
Added missing dispatching after delayed release of seats.
Updated logging for all six situations of execution completion and
seat release.
Added behavioral tests for non-zero extra latency and non-unit width.
Also added two tests for baseline functionality.
Also improved some comments and other logging in `queueset.go`.
Kubernetes-commit: d2a27a58f0af20c6185fa1c21890d666e9d3746b
Add comment outlining TestContextCancel.
Stop calling `t.Errorf` from wrong goroutine.
Package up queueNoteFn expectation checking.
Add counting of goroutine in req1 exec fn.
Remove unnecessary assignment to `_`.
Make TestContextCancel wait on fake clock, to insulate timing check
from scheduler noise.
Factor goroutine counting out of queueset.go, into queueset_test.go,
where it matters.
Refactor promise: Use a simple channel-based implementation for normal
code, a mutex-based one for testing code.
Took all the panics out of queueset.go
Shrink the timeouts in promise tests to 1 second.
Kubernetes-commit: 1db36ae3b30e30d70972998a22987a7db470479b
Rename from `clock` to `eventclock`.
Simplify by removing the prohibition on an EventFunc suspending and
resuming activity.
Remove "EventClock" from names to avoid stuttering.
Start to consolidate test code under fairqueuing/testing/.
Kubernetes-commit: 80ca6a4ae6ff571c32962a7155efd55edefff9e6
So we can move off of the apimachinery clock package.
Switch queueset to new clocks.
Removed event clocks based on apimachinery clocks,
because this PR introduces ones based on k8s.io/utils/clock .
Removed interface that is implemented by only one interesting type.
Simplify RealEventClock::EventAfterTime.
Kubernetes-commit: dcb298c9552de44e27ed52f5e2b58a0dd7cd8d54
- add plumbing that allows us to estimated "width" of a request
- the default implementation returns 1 as the "width" of all
incoming requests, this is in keeping with the current behavior.
Kubernetes-commit: 9b72eb1929a64b9d5a5234090a631ba312fb4d41
Adds counters to generic webhook code and to the kube aggregator
so that it is possible to effectively measure the impact of
Golang 1.15's deprecation of x509 cert CN hostname
verification.
Kubernetes-commit: 9d6a19efff05a40081337a2fcb3dce6331b04022
- don't expose the internal states of the apf controller to the caller
- return a boolean, instead of the priority level states
Kubernetes-commit: f20c6cb2d9060920cae9ff5cade1739c7e0b7f7a
webhook.WithExponentialBackoff returns an error, and the priority is:
- A: if the last invocation of the webhook function returned an error
that error should be returned, otherwise
- B: the error associated with the context if it has been canceled or
it has expired, or the ErrWaitTimeout returned by the wait package
once all retries have been exhausted.
caller should check the error returned by webhook.WithExponentialBackoff
to handle both A and B. Currently, we only handle A.
Kubernetes-commit: ae2b353fbf519b29d168c534f88c373fd67a1c31
When the error is due to the object having been deleted, the
controller does not need to do anything before the coming
notification.
Kubernetes-commit: ef1e2039b5fc7f955ec4f9c636a64aa403cba2ab
Collect the parameters of newTestableController into a named type.
Also tolerate the surprising situation in which a request's user
groups include neither `system:authenticated` nor
`system:unauthenticated` --- because this is observed to happen in
some tests.
Also a few other minor fixups.
Kubernetes-commit: 10df6d459b5bca7b42471f9409182417fbc3f253
Changed quantization to use monotonic clock readings.
Stopping panicing when monotonic clock readings go backwards because
https://github.com/kubernetes/kubernetes/issues/96459 reported it
happening.
Re-organized sampleAndWaterMarkHistograms::innerSet to `defer` the
Unlock call, because that is the preferred pattern.
Kubernetes-commit: 0809220fd04d26892f0fcfd3bf54cc4baeda22da
Currently webhook retry backoff parameters are hard coded, we want
to have the ability to configure the backoff parameters for webhook
retry logic.
Kubernetes-commit: 53a1307f68ccf6c9ffd252eeea2b333e818c1103
- Inside WithExponentialBackoff function, handle error returned
by wait.ExponentialBackoff.
- Ensure that the wait time is bound to the given context.
Kubernetes-commit: f8e35de156f212b6989b465e608dd99b525bd5dc
Introduce min, average, and standard deviation for the number of
executing mutating and readOnly requests.
Introduce min, max, average, and standard deviation for the number
waiting and number waiting per priority level.
Later:
Revised to use a series of windows
Use three individuals instead of array of powers
Later:
Add coarse queue count metrics, removed windowed avg and stddev
Add metrics for number of queued mutating and readOnly requests,
to complement metrics for number executing.
Later:
Removed windowed average and standard deviation because consumers can
derive such from integrals of consumer's chosen window.
Also replaced "requestKind" Prometheus label with "request_kind".
Later:
Revised to focus on sampling
Make the clock intrinsic to a TimedObserver
... so that the clock can be read while holding the observer's lock;
otherwise, forward progress is not guaranteed (and violations were
observed in testing).
Bug fixes and histogram buckets revision
SetX1 to 1 when queue length limit is zero, beause dividing by zero is nasty.
Remove obsolete argument in gen_test.go.
Add a bucket boundary at 0 for sample-and-water-mark histograms, to
distinguish zeroes from non-zeros.
This includes adding Integrator test.
Simplified test code.
More pervasively used "ctlr" instead of "ctl" as abbreviation for
"controller".
Kubernetes-commit: 57ecea22296797a93b0157169db0ff2e477f58d0
The current design for Fair Queueing for Server Requests has a
problem: if the min-max fair result stays different from an even
division for a long time and no queue involved in the imbalance goes
empty then the imbalance keeps accruing in queue virtual state times.
This commit adds a test that demonstrates the problem.
It also has some other tweaks to make other tests less flaky.
Factor the big scenario-testing func into pieces, with supporting
structs.
Kubernetes-commit: f3fdd5cf9f51f2a03ebfddef82bc2014e04b62a0
Mike Spreitzer