-
Notifications
You must be signed in to change notification settings - Fork 1k
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
Add the experimental exemplar feature (#4871)
* Add the experimental exemplar feature * Add exemplars to EXPERIMENTAL.md * Add changelog entry * Fix hist buckets > 1 detection * Collect instead of Flush res about to be deleted * Add e2e test * Do not pre-alloc ResourceMetrics This only has a single use. * Fix grammatical error in comment * Add test cases Default and invalid OTEL_METRICS_EXEMPLAR_FILTER. Test sampled and non-sampled context for trace_based. * Comment nCPU * Doc OTEL_METRICS_EXEMPLAR_FILTER
- Loading branch information
Showing
14 changed files
with
522 additions
and
59 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,96 @@ | ||
| // Copyright The OpenTelemetry Authors | ||
| // | ||
| // Licensed under the Apache License, Version 2.0 (the "License"); | ||
| // you may not use this file except in compliance with the License. | ||
| // You may obtain a copy of the License at | ||
| // | ||
| // http://www.apache.org/licenses/LICENSE-2.0 | ||
| // | ||
| // Unless required by applicable law or agreed to in writing, software | ||
| // distributed under the License is distributed on an "AS IS" BASIS, | ||
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | ||
| // See the License for the specific language governing permissions and | ||
| // limitations under the License. | ||
|
|
||
| package metric // import "go.opentelemetry.io/otel/sdk/metric" | ||
|
|
||
| import ( | ||
| "os" | ||
| "runtime" | ||
|
|
||
| "go.opentelemetry.io/otel/sdk/metric/internal/exemplar" | ||
| "go.opentelemetry.io/otel/sdk/metric/internal/x" | ||
| ) | ||
|
|
||
| // reservoirFunc returns the appropriately configured exemplar reservoir | ||
| // creation func based on the passed InstrumentKind and user defined | ||
| // environment variables. | ||
| // | ||
| // Note: This will only return non-nil values when the experimental exemplar | ||
| // feature is enabled and the OTEL_METRICS_EXEMPLAR_FILTER environment variable | ||
| // is not set to always_off. | ||
| func reservoirFunc[N int64 | float64](agg Aggregation) func() exemplar.Reservoir[N] { | ||
| if !x.Exemplars.Enabled() { | ||
| return nil | ||
| } | ||
|
|
||
| // https://github.com/open-telemetry/opentelemetry-specification/blob/d4b241f451674e8f611bb589477680341006ad2b/specification/metrics/sdk.md#exemplar-defaults | ||
| resF := func() func() exemplar.Reservoir[N] { | ||
| // Explicit bucket histogram aggregation with more than 1 bucket will | ||
| // use AlignedHistogramBucketExemplarReservoir. | ||
| a, ok := agg.(AggregationExplicitBucketHistogram) | ||
| if ok && len(a.Boundaries) > 0 { | ||
| cp := make([]float64, len(a.Boundaries)) | ||
| copy(cp, a.Boundaries) | ||
| return func() exemplar.Reservoir[N] { | ||
| bounds := cp | ||
| return exemplar.Histogram[N](bounds) | ||
| } | ||
| } | ||
|
|
||
| var n int | ||
| if a, ok := agg.(AggregationBase2ExponentialHistogram); ok { | ||
| // Base2 Exponential Histogram Aggregation SHOULD use a | ||
| // SimpleFixedSizeExemplarReservoir with a reservoir equal to the | ||
| // smaller of the maximum number of buckets configured on the | ||
| // aggregation or twenty (e.g. min(20, max_buckets)). | ||
| n = int(a.MaxSize) | ||
| if n > 20 { | ||
| n = 20 | ||
| } | ||
| } else { | ||
| // https://github.com/open-telemetry/opentelemetry-specification/blob/e94af89e3d0c01de30127a0f423e912f6cda7bed/specification/metrics/sdk.md#simplefixedsizeexemplarreservoir | ||
| // This Exemplar reservoir MAY take a configuration parameter for | ||
| // the size of the reservoir. If no size configuration is | ||
| // provided, the default size MAY be the number of possible | ||
| // concurrent threads (e.g. numer of CPUs) to help reduce | ||
| // contention. Otherwise, a default size of 1 SHOULD be used. | ||
| n = runtime.NumCPU() | ||
| if n < 1 { | ||
| // Should never be the case, but be defensive. | ||
| n = 1 | ||
| } | ||
| } | ||
|
|
||
| return func() exemplar.Reservoir[N] { | ||
| return exemplar.FixedSize[N](n) | ||
| } | ||
| } | ||
|
|
||
| // https://github.com/open-telemetry/opentelemetry-specification/blob/d4b241f451674e8f611bb589477680341006ad2b/specification/configuration/sdk-environment-variables.md#exemplar | ||
| const filterEnvKey = "OTEL_METRICS_EXEMPLAR_FILTER" | ||
|
|
||
| switch os.Getenv(filterEnvKey) { | ||
| case "always_on": | ||
| return resF() | ||
| case "always_off": | ||
| return exemplar.Drop[N] | ||
| case "trace_based": | ||
| fallthrough | ||
| default: | ||
| newR := resF() | ||
| return func() exemplar.Reservoir[N] { | ||
| return exemplar.SampledFilter(newR()) | ||
| } | ||
| } | ||
| } |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Oops, something went wrong.