node_exporter/collector/slabinfo_linux.go
Daniel Swarbrick 3fb5f70b0c Drop redundant GOOS build tags if already in filename
Drop redundant GOOS build tags at start of file if the constraint is
already specified by the filename, e.g. foo_GOOS.go or
foo_GOOS_GOARCH.go, avoiding potential confusion in future.

cf. https://pkg.go.dev/cmd/go#hdr-Build_constraints

Signed-off-by: Daniel Swarbrick <daniel.swarbrick@gmail.com>
2023-08-08 14:30:39 +02:00

122 lines
3.5 KiB
Go

// Copyright 2022 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.
//go:build !noslabinfo
// +build !noslabinfo
package collector
import (
"fmt"
"github.com/go-kit/log"
"github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/procfs"
)
type slabinfoCollector struct {
fs procfs.FS
logger log.Logger
subsystem string
labels []string
}
func init() {
registerCollector("slabinfo", defaultDisabled, NewSlabinfoCollector)
}
func NewSlabinfoCollector(logger log.Logger) (Collector, error) {
fs, err := procfs.NewFS(*procPath)
if err != nil {
return nil, fmt.Errorf("failed to open procfs: %w", err)
}
return &slabinfoCollector{logger: logger,
fs: fs,
subsystem: "slabinfo",
labels: []string{"slab"},
}, nil
}
func (c *slabinfoCollector) Update(ch chan<- prometheus.Metric) error {
slabinfo, err := c.fs.SlabInfo()
if err != nil {
return fmt.Errorf("couldn't get %s: %w", c.subsystem, err)
}
for _, slab := range slabinfo.Slabs {
ch <- c.activeObjects(slab.Name, slab.ObjActive)
ch <- c.objects(slab.Name, slab.ObjNum)
ch <- c.objectSizeBytes(slab.Name, slab.ObjSize)
ch <- c.objectsPerSlab(slab.Name, slab.ObjPerSlab)
ch <- c.pagesPerSlab(slab.Name, slab.PagesPerSlab)
}
return nil
}
func (c *slabinfoCollector) activeObjects(label string, val int64) prometheus.Metric {
desc := prometheus.NewDesc(
prometheus.BuildFQName(namespace, c.subsystem, "active_objects"),
"The number of objects that are currently active (i.e., in use).",
c.labels, nil)
return prometheus.MustNewConstMetric(
desc, prometheus.GaugeValue, float64(val), label,
)
}
func (c *slabinfoCollector) objects(label string, val int64) prometheus.Metric {
desc := prometheus.NewDesc(
prometheus.BuildFQName(namespace, c.subsystem, "objects"),
"The total number of allocated objects (i.e., objects that are both in use and not in use).",
c.labels, nil)
return prometheus.MustNewConstMetric(
desc, prometheus.GaugeValue, float64(val), label,
)
}
func (c *slabinfoCollector) objectSizeBytes(label string, val int64) prometheus.Metric {
desc := prometheus.NewDesc(
prometheus.BuildFQName(namespace, c.subsystem, "object_size_bytes"),
"The size of objects in this slab, in bytes.",
c.labels, nil)
return prometheus.MustNewConstMetric(
desc, prometheus.GaugeValue, float64(val), label,
)
}
func (c *slabinfoCollector) objectsPerSlab(label string, val int64) prometheus.Metric {
desc := prometheus.NewDesc(
prometheus.BuildFQName(namespace, c.subsystem, "objects_per_slab"),
"The number of objects stored in each slab.",
c.labels, nil)
return prometheus.MustNewConstMetric(
desc, prometheus.GaugeValue, float64(val), label,
)
}
func (c *slabinfoCollector) pagesPerSlab(label string, val int64) prometheus.Metric {
desc := prometheus.NewDesc(
prometheus.BuildFQName(namespace, c.subsystem, "pages_per_slab"),
"The number of pages allocated for each slab.",
c.labels, nil)
return prometheus.MustNewConstMetric(
desc, prometheus.GaugeValue, float64(val), label,
)
}