mirror of https://github.com/prometheus/prometheus
80 lines
2.2 KiB
Go
80 lines
2.2 KiB
Go
/*
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Copyright 2016 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 retry
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import (
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"time"
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"k8s.io/apimachinery/pkg/api/errors"
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"k8s.io/apimachinery/pkg/util/wait"
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)
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// DefaultRetry is the recommended retry for a conflict where multiple clients
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// are making changes to the same resource.
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var DefaultRetry = wait.Backoff{
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Steps: 5,
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Duration: 10 * time.Millisecond,
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Factor: 1.0,
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Jitter: 0.1,
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}
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// DefaultBackoff is the recommended backoff for a conflict where a client
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// may be attempting to make an unrelated modification to a resource under
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// active management by one or more controllers.
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var DefaultBackoff = wait.Backoff{
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Steps: 4,
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Duration: 10 * time.Millisecond,
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Factor: 5.0,
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Jitter: 0.1,
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}
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// RetryConflict executes the provided function repeatedly, retrying if the server returns a conflicting
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// write. Callers should preserve previous executions if they wish to retry changes. It performs an
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// exponential backoff.
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//
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// var pod *api.Pod
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// err := RetryOnConflict(DefaultBackoff, func() (err error) {
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// pod, err = c.Pods("mynamespace").UpdateStatus(podStatus)
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// return
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// })
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// if err != nil {
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// // may be conflict if max retries were hit
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// return err
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// }
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// ...
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//
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// TODO: Make Backoff an interface?
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func RetryOnConflict(backoff wait.Backoff, fn func() error) error {
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var lastConflictErr error
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err := wait.ExponentialBackoff(backoff, func() (bool, error) {
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err := fn()
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switch {
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case err == nil:
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return true, nil
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case errors.IsConflict(err):
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lastConflictErr = err
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return false, nil
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default:
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return false, err
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}
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})
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if err == wait.ErrWaitTimeout {
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err = lastConflictErr
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}
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return err
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}
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