143d9f71cc
ocagent allows users to send traces out of VK to a "standard" external forwarder (standard as in this is a format/protocol defined in the opencensus project). This allows uers to implement metrics for whatever backend they want without having to add it into VK directly.
39 lines
1.2 KiB
Go
39 lines
1.2 KiB
Go
// Copyright 2018, OpenCensus Authors
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//
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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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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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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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package ocagent
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import (
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"math/rand"
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"time"
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)
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var randSrc = rand.New(rand.NewSource(time.Now().UnixNano()))
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// retries function fn upto n times, if fn returns an error lest it returns nil early.
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// It applies exponential backoff in units of (1<<n) + jitter microsends.
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func nTriesWithExponentialBackoff(nTries int64, timeBaseUnit time.Duration, fn func() error) (err error) {
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for i := int64(0); i < nTries; i++ {
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err = fn()
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if err == nil {
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return nil
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}
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// Backoff for a time period with a pseudo-random jitter
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jitter := time.Duration(randSrc.Float64()*100) * time.Microsecond
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ts := jitter + ((1 << uint64(i)) * timeBaseUnit)
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<-time.After(ts)
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}
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return err
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}
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