8337031bf5
Since the HPA controller pulls information from an external source that makes no guarantees about consistency, it's possible for the HPA to get into an infinite update loop -- if the metrics change with every query, the HPA controller will run it's normal reconcilation, post a status update, see that status update itself, fetch new metrics, and if those metrics are different, post another status update, and repeat. This can lead to continuously updating a single HPA. By rate-limiting each HPA to once per sync interval, we prevent this from happening.
54 lines
1.5 KiB
Go
54 lines
1.5 KiB
Go
/*
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Copyright 2015 The Kubernetes Authors.
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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package podautoscaler
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import (
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"time"
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"k8s.io/client-go/util/workqueue"
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)
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// FixedItemIntervalRateLimiter limits items to a fixed-rate interval
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type FixedItemIntervalRateLimiter struct {
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interval time.Duration
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}
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var _ workqueue.RateLimiter = &FixedItemIntervalRateLimiter{}
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func NewFixedItemIntervalRateLimiter(interval time.Duration) workqueue.RateLimiter {
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return &FixedItemIntervalRateLimiter{
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interval: interval,
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}
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}
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func (r *FixedItemIntervalRateLimiter) When(item interface{}) time.Duration {
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return r.interval
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}
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func (r *FixedItemIntervalRateLimiter) NumRequeues(item interface{}) int {
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return 1
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}
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func (r *FixedItemIntervalRateLimiter) Forget(item interface{}) {
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}
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// NewDefaultHPARateLimitter creates a rate limitter which limits overall (as per the
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// default controller rate limiter), as well as per the resync interval
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func NewDefaultHPARateLimiter(interval time.Duration) workqueue.RateLimiter {
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return NewFixedItemIntervalRateLimiter(interval)
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}
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