Assuming that there is only one admission controller Pod running, and the admission controller has a webhook that will be triggered by Pod deletion events.
Example Scenario
There are 2 Pods (Pod A and Pod B) within a namespace. 2 different users (Alice and Bob) perform Pod deletion at the exact same time, in which:
- Alice deletes the Pod A
- Bob deletes the Pod B
In this specific scenario, will the admission controller handle both the admission requests serially or in parallel? In other words, will the admission controller handle the admission request for Pod A before that of Pod B (or vice versa), or will it handle both the admission requests are the same time?
General Scenario
The admission requests are sent from the API Server to the admission controller. Generally speaking, will it be possible that multiple admission requests are sent to the admission controller at the exact same time?
And if so, will the admission controller handle them in parallel via some built-in parallelism mechanism, or will the admission controller queue them and process them serially?
CodePudding user response：
By Andrew Skorkin:
Since in kube-api options we can see --max-mutating-requests-inflight and --max-requests-inflight flags, which are used to determine the server's total concurrency limit, I think that admission controller also support multi-threading. Because otherwise it will be a bottleneck for proceeding with API requests.