85eb76f2fd
```go
type interInst struct {
x int
}
type inter interface {
}
var sink []inter
func BenchmarkX(b *testing.B) {
sink = make([]inter, b.N)
for i := 0; i < b.N; i++ {
sink[i] = &interInst{}
}
clear(sink)
sink = sink[:0]
runtime.GC()
var ms runtime.MemStats
runtime.ReadMemStats(&ms)
b.Log(b.N, ms.Frees) // Frees is the cumulative count of heap objects freed.
}
```
```
clear:
ioz_test.go:35: 1 589
ioz_test.go:35: 100 711
ioz_test.go:35: 10000 10729
ioz_test.go:35: 1000000 1010750 <-- 1m+ freed
ioz_test.go:35: 16076874 17087643
ioz_test.go:35: 19514749 36602412
```
```
no clear:
ioz_test.go:35: 1 585
ioz_test.go:35: 100 606
ioz_test.go:35: 10000 725
ioz_test.go:35: 1000000 10745 <-- some "overhead" objects freed, not the slice.
ioz_test.go:35: 16391445 1010765
ioz_test.go:35: 21765238 17402230
```
This is documented at https://go.dev/wiki/SliceTricks:
> NOTE If the type of the element is a pointer or a struct with pointer
fields, which need to be garbage collected, the above implementations of
Cut and Delete have a potential memory leak problem: some elements with
values are still referenced by slice a’s underlying array, just not
“visible” in the slice. Because the “deleted” value is referenced in the
underlying array, the deleted value is still “reachable” during GC, even
though the value cannot be referenced by your code. If the underlying
array is long-lived, this represents a leak.
Followed by examples of how zeroing out the slice elements solves
the problem. This PR does the same.
OpenTelemetry-Go
OpenTelemetry-Go is the Go implementation of OpenTelemetry. It provides a set of APIs to directly measure performance and behavior of your software and send this data to observability platforms.
Project Status
| Signal | Status |
|---|---|
| Traces | Stable |
| Metrics | Stable |
| Logs | Beta1 |
Progress and status specific to this repository is tracked in our project boards and milestones.
Project versioning information and stability guarantees can be found in the versioning documentation.
Compatibility
OpenTelemetry-Go ensures compatibility with the current supported versions of the Go language:
Each major Go release is supported until there are two newer major releases. For example, Go 1.5 was supported until the Go 1.7 release, and Go 1.6 was supported until the Go 1.8 release.
For versions of Go that are no longer supported upstream, opentelemetry-go will stop ensuring compatibility with these versions in the following manner:
- A minor release of opentelemetry-go will be made to add support for the new supported release of Go.
- The following minor release of opentelemetry-go will remove compatibility testing for the oldest (now archived upstream) version of Go. This, and future, releases of opentelemetry-go may include features only supported by the currently supported versions of Go.
Currently, this project supports the following environments.
| OS | Go Version | Architecture |
|---|---|---|
| Ubuntu | 1.23 | amd64 |
| Ubuntu | 1.22 | amd64 |
| Ubuntu | 1.23 | 386 |
| Ubuntu | 1.22 | 386 |
| Linux | 1.23 | arm64 |
| Linux | 1.22 | arm64 |
| macOS 13 | 1.23 | amd64 |
| macOS 13 | 1.22 | amd64 |
| macOS | 1.23 | arm64 |
| macOS | 1.22 | arm64 |
| Windows | 1.23 | amd64 |
| Windows | 1.22 | amd64 |
| Windows | 1.23 | 386 |
| Windows | 1.22 | 386 |
While this project should work for other systems, no compatibility guarantees are made for those systems currently.
Getting Started
You can find a getting started guide on opentelemetry.io.
OpenTelemetry's goal is to provide a single set of APIs to capture distributed traces and metrics from your application and send them to an observability platform. This project allows you to do just that for applications written in Go. There are two steps to this process: instrument your application, and configure an exporter.
Instrumentation
To start capturing distributed traces and metric events from your application it first needs to be instrumented. The easiest way to do this is by using an instrumentation library for your code. Be sure to check out the officially supported instrumentation libraries.
If you need to extend the telemetry an instrumentation library provides or want to build your own instrumentation for your application directly you will need to use the Go otel package. The examples are a good way to see some practical uses of this process.
Export
Now that your application is instrumented to collect telemetry, it needs an export pipeline to send that telemetry to an observability platform.
All officially supported exporters for the OpenTelemetry project are contained in the exporters directory.
| Exporter | Logs | Metrics | Traces |
|---|---|---|---|
| OTLP | ✓ | ✓ | ✓ |
| Prometheus | ✓ | ||
| stdout | ✓ | ✓ | ✓ |
| Zipkin | ✓ |
Contributing
See the contributing documentation.