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DRA API: bump maximum size of ReservedFor to 256

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The original limit of 32 seemed sufficient for a single GPU on a node. But for
shared non-local resources it is too low. For example, a ResourceClaim might be
used to allocate an interconnect channel that connects all pods of a workload
running on several different nodes, in which case the number of pods can be
considerably larger.

256 is high enough for currently planned systems. If we need something even
higher in the future, an alternative approach might be needed to avoid
scalability problems.

Normally, increasing such a limit would have to be done incrementally over two
releases. In this case we decided on
Slack (https://kubernetes.slack.com/archives/CJUQN3E4T/p1734593174791519) to
make an exception and apply this change to current master for 1.33 and backport
it to the next 1.32.x patch release for production usage.

This breaks downgrades to a 1.32 release without this change if there are
ResourceClaims with a number of consumers > 32 in ReservedFor. In practice,
this breakage is very unlikely because there are no workloads yet which need so
many consumers and such downgrades to a previous patch release are also
unlikely. Downgrades to 1.31 already weren't supported when using DRA v1beta1.
This commit is contained in:
Patrick Ohly
2025-01-09 11:41:44 +01:00
parent 117a48fcdf
commit a5de75458e
11 changed files with 19 additions and 19 deletions
Download Patch File Download Diff File Expand all files Collapse all files

4
api/openapi-spec/swagger.json generated
View File

@@ -15123,7 +15123,7 @@
"x-kubernetes-list-type": "map"
},
"reservedFor": {
"description": "ReservedFor indicates which entities are currently allowed to use the claim. A Pod which references a ResourceClaim which is not reserved for that Pod will not be started. A claim that is in use or might be in use because it has been reserved must not get deallocated.\n\nIn a cluster with multiple scheduler instances, two pods might get scheduled concurrently by different schedulers. When they reference the same ResourceClaim which already has reached its maximum number of consumers, only one pod can be scheduled.\n\nBoth schedulers try to add their pod to the claim.status.reservedFor field, but only the update that reaches the API server first gets stored. The other one fails with an error and the scheduler which issued it knows that it must put the pod back into the queue, waiting for the ResourceClaim to become usable again.\n\nThere can be at most 32 such reservations. This may get increased in the future, but not reduced.",
"description": "ReservedFor indicates which entities are currently allowed to use the claim. A Pod which references a ResourceClaim which is not reserved for that Pod will not be started. A claim that is in use or might be in use because it has been reserved must not get deallocated.\n\nIn a cluster with multiple scheduler instances, two pods might get scheduled concurrently by different schedulers. When they reference the same ResourceClaim which already has reached its maximum number of consumers, only one pod can be scheduled.\n\nBoth schedulers try to add their pod to the claim.status.reservedFor field, but only the update that reaches the API server first gets stored. The other one fails with an error and the scheduler which issued it knows that it must put the pod back into the queue, waiting for the ResourceClaim to become usable again.\n\nThere can be at most 256 such reservations. This may get increased in the future, but not reduced.",
"items": {
"$ref": "#/definitions/io.k8s.api.resource.v1alpha3.ResourceClaimConsumerReference"
},
@@ -15956,7 +15956,7 @@
"x-kubernetes-list-type": "map"
},
"reservedFor": {
"description": "ReservedFor indicates which entities are currently allowed to use the claim. A Pod which references a ResourceClaim which is not reserved for that Pod will not be started. A claim that is in use or might be in use because it has been reserved must not get deallocated.\n\nIn a cluster with multiple scheduler instances, two pods might get scheduled concurrently by different schedulers. When they reference the same ResourceClaim which already has reached its maximum number of consumers, only one pod can be scheduled.\n\nBoth schedulers try to add their pod to the claim.status.reservedFor field, but only the update that reaches the API server first gets stored. The other one fails with an error and the scheduler which issued it knows that it must put the pod back into the queue, waiting for the ResourceClaim to become usable again.\n\nThere can be at most 32 such reservations. This may get increased in the future, but not reduced.",
"description": "ReservedFor indicates which entities are currently allowed to use the claim. A Pod which references a ResourceClaim which is not reserved for that Pod will not be started. A claim that is in use or might be in use because it has been reserved must not get deallocated.\n\nIn a cluster with multiple scheduler instances, two pods might get scheduled concurrently by different schedulers. When they reference the same ResourceClaim which already has reached its maximum number of consumers, only one pod can be scheduled.\n\nBoth schedulers try to add their pod to the claim.status.reservedFor field, but only the update that reaches the API server first gets stored. The other one fails with an error and the scheduler which issued it knows that it must put the pod back into the queue, waiting for the ResourceClaim to become usable again.\n\nThere can be at most 256 such reservations. This may get increased in the future, but not reduced.",
"items": {
"$ref": "#/definitions/io.k8s.api.resource.v1beta1.ResourceClaimConsumerReference"
},

2
api/openapi-spec/v3/apis__resource.k8s.io__v1alpha3_openapi.json generated
View File

@@ -847,7 +847,7 @@
"x-kubernetes-list-type": "map"
},
"reservedFor": {
"description": "ReservedFor indicates which entities are currently allowed to use the claim. A Pod which references a ResourceClaim which is not reserved for that Pod will not be started. A claim that is in use or might be in use because it has been reserved must not get deallocated.\n\nIn a cluster with multiple scheduler instances, two pods might get scheduled concurrently by different schedulers. When they reference the same ResourceClaim which already has reached its maximum number of consumers, only one pod can be scheduled.\n\nBoth schedulers try to add their pod to the claim.status.reservedFor field, but only the update that reaches the API server first gets stored. The other one fails with an error and the scheduler which issued it knows that it must put the pod back into the queue, waiting for the ResourceClaim to become usable again.\n\nThere can be at most 32 such reservations. This may get increased in the future, but not reduced.",
"description": "ReservedFor indicates which entities are currently allowed to use the claim. A Pod which references a ResourceClaim which is not reserved for that Pod will not be started. A claim that is in use or might be in use because it has been reserved must not get deallocated.\n\nIn a cluster with multiple scheduler instances, two pods might get scheduled concurrently by different schedulers. When they reference the same ResourceClaim which already has reached its maximum number of consumers, only one pod can be scheduled.\n\nBoth schedulers try to add their pod to the claim.status.reservedFor field, but only the update that reaches the API server first gets stored. The other one fails with an error and the scheduler which issued it knows that it must put the pod back into the queue, waiting for the ResourceClaim to become usable again.\n\nThere can be at most 256 such reservations. This may get increased in the future, but not reduced.",
"items": {
"allOf": [
{

2
api/openapi-spec/v3/apis__resource.k8s.io__v1beta1_openapi.json generated
View File

@@ -869,7 +869,7 @@
"x-kubernetes-list-type": "map"
},
"reservedFor": {
"description": "ReservedFor indicates which entities are currently allowed to use the claim. A Pod which references a ResourceClaim which is not reserved for that Pod will not be started. A claim that is in use or might be in use because it has been reserved must not get deallocated.\n\nIn a cluster with multiple scheduler instances, two pods might get scheduled concurrently by different schedulers. When they reference the same ResourceClaim which already has reached its maximum number of consumers, only one pod can be scheduled.\n\nBoth schedulers try to add their pod to the claim.status.reservedFor field, but only the update that reaches the API server first gets stored. The other one fails with an error and the scheduler which issued it knows that it must put the pod back into the queue, waiting for the ResourceClaim to become usable again.\n\nThere can be at most 32 such reservations. This may get increased in the future, but not reduced.",
"description": "ReservedFor indicates which entities are currently allowed to use the claim. A Pod which references a ResourceClaim which is not reserved for that Pod will not be started. A claim that is in use or might be in use because it has been reserved must not get deallocated.\n\nIn a cluster with multiple scheduler instances, two pods might get scheduled concurrently by different schedulers. When they reference the same ResourceClaim which already has reached its maximum number of consumers, only one pod can be scheduled.\n\nBoth schedulers try to add their pod to the claim.status.reservedFor field, but only the update that reaches the API server first gets stored. The other one fails with an error and the scheduler which issued it knows that it must put the pod back into the queue, waiting for the ResourceClaim to become usable again.\n\nThere can be at most 256 such reservations. This may get increased in the future, but not reduced.",
"items": {
"allOf": [
{