scheduler: merge Reserve and Unreserve plugins

Previously, separate interfaces were defined for Reserve and Unreserve
plugins. However, in nearly all cases, a plugin that allocates a
resource using Reserve will likely want to register itself for Unreserve
as well in order to free the allocated resource at the end of a failed
scheduling/binding cycle. Having separate plugins for Reserve and
Unreserve also adds unnecessary config toil. To that end, this patch
aims to merge the two plugins into a single interface called a
ReservePlugin that requires implementing both the Reserve and Unreserve
methods.
This commit is contained in:
Adhityaa Chandrasekar
2020-06-15 21:52:54 +00:00
parent 8adcd7978e
commit ec83143342
23 changed files with 243 additions and 288 deletions

View File

@@ -324,17 +324,21 @@ type ScorePlugin interface {
ScoreExtensions() ScoreExtensions
}
// ReservePlugin is an interface for Reserve plugins. These plugins are called
// at the reservation point. These are meant to update the state of the plugin.
// This concept used to be called 'assume' in the original scheduler.
// These plugins should return only Success or Error in Status.code. However,
// the scheduler accepts other valid codes as well. Anything other than Success
// will lead to rejection of the pod.
// ReservePlugin is an interface for plugins with Reserve and Unreserve
// methods. These are meant to update the state of the plugin. This concept
// used to be called 'assume' in the original scheduler. These plugins should
// return only Success or Error in Status.code. However, the scheduler accepts
// other valid codes as well. Anything other than Success will lead to
// rejection of the pod.
type ReservePlugin interface {
Plugin
// Reserve is called by the scheduling framework when the scheduler cache is
// updated.
Reserve(ctx context.Context, state *CycleState, p *v1.Pod, nodeName string) *Status
// Unreserve is called by the scheduling framework when a reserved pod was
// rejected, an error occurred during reservation of subsequent plugins, or
// in a later phase. The Unreserve method implementation must be idempotent.
Unreserve(ctx context.Context, state *CycleState, p *v1.Pod, nodeName string)
}
// PreBindPlugin is an interface that must be implemented by "prebind" plugins.
@@ -357,17 +361,6 @@ type PostBindPlugin interface {
PostBind(ctx context.Context, state *CycleState, p *v1.Pod, nodeName string)
}
// UnreservePlugin is an interface for Unreserve plugins. This is an informational
// extension point. If a pod was reserved and then rejected in a later phase, then
// un-reserve plugins will be notified. Un-reserve plugins should clean up state
// associated with the reserved Pod.
type UnreservePlugin interface {
Plugin
// Unreserve is called by the scheduling framework when a reserved pod was
// rejected in a later phase.
Unreserve(ctx context.Context, state *CycleState, p *v1.Pod, nodeName string)
}
// PermitPlugin is an interface that must be implemented by "permit" plugins.
// These plugins are called before a pod is bound to a node.
type PermitPlugin interface {
@@ -452,13 +445,15 @@ type Framework interface {
// RunPostBindPlugins runs the set of configured postbind plugins.
RunPostBindPlugins(ctx context.Context, state *CycleState, pod *v1.Pod, nodeName string)
// RunReservePlugins runs the set of configured reserve plugins. If any of these
// plugins returns an error, it does not continue running the remaining ones and
// returns the error. In such case, pod will not be scheduled.
RunReservePlugins(ctx context.Context, state *CycleState, pod *v1.Pod, nodeName string) *Status
// RunReservePluginsReserve runs the Reserve method of the set of
// configured reserve plugins. If any of these calls returns an error, it
// does not continue running the remaining ones and returns the error. In
// such case, pod will not be scheduled.
RunReservePluginsReserve(ctx context.Context, state *CycleState, pod *v1.Pod, nodeName string) *Status
// RunUnreservePlugins runs the set of configured unreserve plugins.
RunUnreservePlugins(ctx context.Context, state *CycleState, pod *v1.Pod, nodeName string)
// RunReservePluginsUnreserve runs the Unreserve method of the set of
// configured reserve plugins.
RunReservePluginsUnreserve(ctx context.Context, state *CycleState, pod *v1.Pod, nodeName string)
// RunPermitPlugins runs the set of configured permit plugins. If any of these
// plugins returns a status other than "Success" or "Wait", it does not continue