forked from mirror/client_golang
70 lines
3.6 KiB
Go
70 lines
3.6 KiB
Go
// Copyright 2021 The Prometheus 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 collectors
|
|
|
|
import "github.com/prometheus/client_golang/prometheus"
|
|
|
|
// NewGoCollector returns a collector that exports metrics about the current Go
|
|
// process. This includes memory stats. To collect those, runtime.ReadMemStats
|
|
// is called. This requires to “stop the world”, which usually only happens for
|
|
// garbage collection (GC). Take the following implications into account when
|
|
// deciding whether to use the Go collector:
|
|
//
|
|
// 1. The performance impact of stopping the world is the more relevant the more
|
|
// frequently metrics are collected. However, with Go1.9 or later the
|
|
// stop-the-world time per metrics collection is very short (~25µs) so that the
|
|
// performance impact will only matter in rare cases. However, with older Go
|
|
// versions, the stop-the-world duration depends on the heap size and can be
|
|
// quite significant (~1.7 ms/GiB as per
|
|
// https://go-review.googlesource.com/c/go/+/34937).
|
|
//
|
|
// 2. During an ongoing GC, nothing else can stop the world. Therefore, if the
|
|
// metrics collection happens to coincide with GC, it will only complete after
|
|
// GC has finished. Usually, GC is fast enough to not cause problems. However,
|
|
// with a very large heap, GC might take multiple seconds, which is enough to
|
|
// cause scrape timeouts in common setups. To avoid this problem, the Go
|
|
// collector will use the memstats from a previous collection if
|
|
// runtime.ReadMemStats takes more than 1s. However, if there are no previously
|
|
// collected memstats, or their collection is more than 5m ago, the collection
|
|
// will block until runtime.ReadMemStats succeeds.
|
|
//
|
|
// NOTE: The problem is solved in Go 1.15, see
|
|
// https://github.com/golang/go/issues/19812 for the related Go issue.
|
|
func NewGoCollector() prometheus.Collector {
|
|
//nolint:staticcheck // Ignore SA1019 until v2.
|
|
return prometheus.NewGoCollector()
|
|
}
|
|
|
|
// NewBuildInfoCollector returns a collector collecting a single metric
|
|
// "go_build_info" with the constant value 1 and three labels "path", "version",
|
|
// and "checksum". Their label values contain the main module path, version, and
|
|
// checksum, respectively. The labels will only have meaningful values if the
|
|
// binary is built with Go module support and from source code retrieved from
|
|
// the source repository (rather than the local file system). This is usually
|
|
// accomplished by building from outside of GOPATH, specifying the full address
|
|
// of the main package, e.g. "GO111MODULE=on go run
|
|
// github.com/prometheus/client_golang/examples/random". If built without Go
|
|
// module support, all label values will be "unknown". If built with Go module
|
|
// support but using the source code from the local file system, the "path" will
|
|
// be set appropriately, but "checksum" will be empty and "version" will be
|
|
// "(devel)".
|
|
//
|
|
// This collector uses only the build information for the main module. See
|
|
// https://github.com/povilasv/prommod for an example of a collector for the
|
|
// module dependencies.
|
|
func NewBuildInfoCollector() prometheus.Collector {
|
|
//nolint:staticcheck // Ignore SA1019 until v2.
|
|
return prometheus.NewBuildInfoCollector()
|
|
}
|