ref!: convert linux meminfo implementation to use procfs lib (#3049)

* ref!: convert linux meminfo implementation to use procfs lib Part of #2957 Prometheus' procfs lib supports collecting memory info and we're using a new enough version of the lib that has it available, so this converts the meminfo collector for Linux to use data from procfs lib instead. The bits I've touched for darwin/openbsd/netbsd are with intent to preserve the original struct implementation/backwards compatibility. Signed-off-by: TJ Hoplock <t.hoplock@gmail.com> * fix: meminfo debug log unsupported value Fixes: ``` ts=2024-06-11T19:04:55.591Z caller=meminfo.go:44 level=debug collector=meminfo msg="Set node_mem" memInfo="unsupported value type" ``` Signed-off-by: TJ Hoplock <t.hoplock@gmail.com> * fix: don't coerce nil Meminfo entries to 0, leave out if nil Nil entries in procfs.Meminfo fields indicate that the value isn't present on the system. Coercing those nil values to `0` introduces new metrics on systems that should not be present and can break some queries. Addresses PR feedback: https://github.com/prometheus/node_exporter/pull/3049#discussion_r1637581536 https://github.com/prometheus/node_exporter/pull/3049#discussion_r1637584482 Signed-off-by: TJ Hoplock <t.hoplock@gmail.com> --------- Signed-off-by: TJ Hoplock <t.hoplock@gmail.com>
2024-07-14 08:27:55 -04:00 · 2024-07-14 08:27:55 -04:00 · fdaa8fc00d
parent e8aa4de7c5
commit fdaa8fc00d
7 changed files with 240 additions and 66 deletions
--- a/collector/meminfo.go
+++ b/collector/meminfo.go
@ -21,7 +21,6 @@ import (
 	"fmt"
 	"strings"

-	"github.com/go-kit/log"
 	"github.com/go-kit/log/level"
 	"github.com/prometheus/client_golang/prometheus"
 )
@ -30,19 +29,10 @@ const (
 	memInfoSubsystem = "memory"
 )

-type meminfoCollector struct {
-	logger log.Logger
-}
-
 func init() {
 	registerCollector("meminfo", defaultEnabled, NewMeminfoCollector)
 }

-// NewMeminfoCollector returns a new Collector exposing memory stats.
-func NewMeminfoCollector(logger log.Logger) (Collector, error) {
-	return &meminfoCollector{logger}, nil
-}
-
 // Update calls (*meminfoCollector).getMemInfo to get the platform specific
 // memory metrics.
 func (c *meminfoCollector) Update(ch chan<- prometheus.Metric) error {
@ -51,7 +41,7 @@ func (c *meminfoCollector) Update(ch chan<- prometheus.Metric) error {
 	if err != nil {
 		return fmt.Errorf("couldn't get meminfo: %w", err)
 	}
-	level.Debug(c.logger).Log("msg", "Set node_mem", "memInfo", memInfo)
+	level.Debug(c.logger).Log("msg", "Set node_mem", "memInfo", fmt.Sprintf("%v", memInfo))
 	for k, v := range memInfo {
 		if strings.HasSuffix(k, "_total") {
 			metricType = prometheus.CounterValue
--- a/collector/meminfo_darwin.go
+++ b/collector/meminfo_darwin.go
@ -26,9 +26,21 @@ import (
 	"fmt"
 	"unsafe"

+	"github.com/go-kit/log"
 	"golang.org/x/sys/unix"
 )

+type meminfoCollector struct {
+	logger log.Logger
+}
+
+// NewMeminfoCollector returns a new Collector exposing memory stats.
+func NewMeminfoCollector(logger log.Logger) (Collector, error) {
+	return &meminfoCollector{
+		logger: logger,
+	}, nil
+}
+
 func (c *meminfoCollector) getMemInfo() (map[string]float64, error) {
 	host := C.mach_host_self()
 	infoCount := C.mach_msg_type_number_t(C.HOST_VM_INFO64_COUNT)
--- a/collector/meminfo_linux.go
+++ b/collector/meminfo_linux.go
@ -17,59 +17,189 @@
 package collector

 import (
-	"bufio"
 	"fmt"
-	"io"
-	"os"
-	"regexp"
-	"strconv"
-	"strings"
+
+	"github.com/go-kit/log"
+	"github.com/prometheus/procfs"
 )

-var (
-	reParens = regexp.MustCompile(`\((.*)\)`)
-)
+type meminfoCollector struct {
+	fs     procfs.FS
+	logger log.Logger
+}
+
+// NewMeminfoCollector returns a new Collector exposing memory stats.
+func NewMeminfoCollector(logger log.Logger) (Collector, error) {
+	fs, err := procfs.NewFS(*procPath)
+	if err != nil {
+		return nil, fmt.Errorf("failed to open procfs: %w", err)
+	}
+
+	return &meminfoCollector{
+		logger: logger,
+		fs:     fs,
+	}, nil
+}

 func (c *meminfoCollector) getMemInfo() (map[string]float64, error) {
-	file, err := os.Open(procFilePath("meminfo"))
+	meminfo, err := c.fs.Meminfo()
 	if err != nil {
-		return nil, err
-	}
-	defer file.Close()
-
-	return parseMemInfo(file)
-}
-
-func parseMemInfo(r io.Reader) (map[string]float64, error) {
-	var (
-		memInfo = map[string]float64{}
-		scanner = bufio.NewScanner(r)
-	)
-
-	for scanner.Scan() {
-		line := scanner.Text()
-		parts := strings.Fields(line)
-		// Workaround for empty lines occasionally occur in CentOS 6.2 kernel 3.10.90.
-		if len(parts) == 0 {
-			continue
-		}
-		fv, err := strconv.ParseFloat(parts[1], 64)
-		if err != nil {
-			return nil, fmt.Errorf("invalid value in meminfo: %w", err)
-		}
-		key := parts[0][:len(parts[0])-1] // remove trailing : from key
-		// Active(anon) -> Active_anon
-		key = reParens.ReplaceAllString(key, "_${1}")
-		switch len(parts) {
-		case 2: // no unit
-		case 3: // has unit, we presume kB
-			fv *= 1024
-			key = key + "_bytes"
-		default:
-			return nil, fmt.Errorf("invalid line in meminfo: %s", line)
-		}
-		memInfo[key] = fv
+		return nil, fmt.Errorf("Failed to get memory info: %s", err)
 	}

-	return memInfo, scanner.Err()
+	metrics := make(map[string]float64)
+
+	if meminfo.ActiveBytes != nil {
+		metrics["Active_bytes"] = float64(*meminfo.ActiveBytes)
+	}
+	if meminfo.ActiveAnonBytes != nil {
+		metrics["Active_anon_bytes"] = float64(*meminfo.ActiveAnonBytes)
+	}
+	if meminfo.ActiveFileBytes != nil {
+		metrics["Active_file_bytes"] = float64(*meminfo.ActiveFileBytes)
+	}
+	if meminfo.AnonHugePagesBytes != nil {
+		metrics["AnonHugePages_bytes"] = float64(*meminfo.AnonHugePagesBytes)
+	}
+	if meminfo.AnonPagesBytes != nil {
+		metrics["AnonPages_bytes"] = float64(*meminfo.AnonPagesBytes)
+	}
+	if meminfo.BounceBytes != nil {
+		metrics["Bounce_bytes"] = float64(*meminfo.BounceBytes)
+	}
+	if meminfo.BuffersBytes != nil {
+		metrics["Buffers_bytes"] = float64(*meminfo.BuffersBytes)
+	}
+	if meminfo.CachedBytes != nil {
+		metrics["Cached_bytes"] = float64(*meminfo.CachedBytes)
+	}
+	if meminfo.CmaFreeBytes != nil {
+		metrics["CmaFree_bytes"] = float64(*meminfo.CmaFreeBytes)
+	}
+	if meminfo.CmaTotalBytes != nil {
+		metrics["CmaTotal_bytes"] = float64(*meminfo.CmaTotalBytes)
+	}
+	if meminfo.CommitLimitBytes != nil {
+		metrics["CommitLimit_bytes"] = float64(*meminfo.CommitLimitBytes)
+	}
+	if meminfo.CommittedASBytes != nil {
+		metrics["Committed_AS_bytes"] = float64(*meminfo.CommittedASBytes)
+	}
+	if meminfo.DirectMap1GBytes != nil {
+		metrics["DirectMap1G_bytes"] = float64(*meminfo.DirectMap1GBytes)
+	}
+	if meminfo.DirectMap2MBytes != nil {
+		metrics["DirectMap2M_bytes"] = float64(*meminfo.DirectMap2MBytes)
+	}
+	if meminfo.DirectMap4kBytes != nil {
+		metrics["DirectMap4k_bytes"] = float64(*meminfo.DirectMap4kBytes)
+	}
+	if meminfo.DirtyBytes != nil {
+		metrics["Dirty_bytes"] = float64(*meminfo.DirtyBytes)
+	}
+	if meminfo.HardwareCorruptedBytes != nil {
+		metrics["HardwareCorrupted_bytes"] = float64(*meminfo.HardwareCorruptedBytes)
+	}
+	if meminfo.HugepagesizeBytes != nil {
+		metrics["Hugepagesize_bytes"] = float64(*meminfo.HugepagesizeBytes)
+	}
+	if meminfo.InactiveBytes != nil {
+		metrics["Inactive_bytes"] = float64(*meminfo.InactiveBytes)
+	}
+	if meminfo.InactiveAnonBytes != nil {
+		metrics["Inactive_anon_bytes"] = float64(*meminfo.InactiveAnonBytes)
+	}
+	if meminfo.InactiveFileBytes != nil {
+		metrics["Inactive_file_bytes"] = float64(*meminfo.InactiveFileBytes)
+	}
+	if meminfo.KernelStackBytes != nil {
+		metrics["KernelStack_bytes"] = float64(*meminfo.KernelStackBytes)
+	}
+	if meminfo.MappedBytes != nil {
+		metrics["Mapped_bytes"] = float64(*meminfo.MappedBytes)
+	}
+	if meminfo.MemAvailableBytes != nil {
+		metrics["MemAvailable_bytes"] = float64(*meminfo.MemAvailableBytes)
+	}
+	if meminfo.MemFreeBytes != nil {
+		metrics["MemFree_bytes"] = float64(*meminfo.MemFreeBytes)
+	}
+	if meminfo.MemTotalBytes != nil {
+		metrics["MemTotal_bytes"] = float64(*meminfo.MemTotalBytes)
+	}
+	if meminfo.MlockedBytes != nil {
+		metrics["Mlocked_bytes"] = float64(*meminfo.MlockedBytes)
+	}
+	if meminfo.NFSUnstableBytes != nil {
+		metrics["NFS_Unstable_bytes"] = float64(*meminfo.NFSUnstableBytes)
+	}
+	if meminfo.PageTablesBytes != nil {
+		metrics["PageTables_bytes"] = float64(*meminfo.PageTablesBytes)
+	}
+	if meminfo.PercpuBytes != nil {
+		metrics["Percpu_bytes"] = float64(*meminfo.PercpuBytes)
+	}
+	if meminfo.SReclaimableBytes != nil {
+		metrics["SReclaimable_bytes"] = float64(*meminfo.SReclaimableBytes)
+	}
+	if meminfo.SUnreclaimBytes != nil {
+		metrics["SUnreclaim_bytes"] = float64(*meminfo.SUnreclaimBytes)
+	}
+	if meminfo.ShmemBytes != nil {
+		metrics["Shmem_bytes"] = float64(*meminfo.ShmemBytes)
+	}
+	if meminfo.ShmemHugePagesBytes != nil {
+		metrics["ShmemHugePages_bytes"] = float64(*meminfo.ShmemHugePagesBytes)
+	}
+	if meminfo.ShmemPmdMappedBytes != nil {
+		metrics["ShmemPmdMapped_bytes"] = float64(*meminfo.ShmemPmdMappedBytes)
+	}
+	if meminfo.SlabBytes != nil {
+		metrics["Slab_bytes"] = float64(*meminfo.SlabBytes)
+	}
+	if meminfo.SwapCachedBytes != nil {
+		metrics["SwapCached_bytes"] = float64(*meminfo.SwapCachedBytes)
+	}
+	if meminfo.SwapFreeBytes != nil {
+		metrics["SwapFree_bytes"] = float64(*meminfo.SwapFreeBytes)
+	}
+	if meminfo.SwapTotalBytes != nil {
+		metrics["SwapTotal_bytes"] = float64(*meminfo.SwapTotalBytes)
+	}
+	if meminfo.UnevictableBytes != nil {
+		metrics["Unevictable_bytes"] = float64(*meminfo.UnevictableBytes)
+	}
+	if meminfo.VmallocChunkBytes != nil {
+		metrics["VmallocChunk_bytes"] = float64(*meminfo.VmallocChunkBytes)
+	}
+	if meminfo.VmallocTotalBytes != nil {
+		metrics["VmallocTotal_bytes"] = float64(*meminfo.VmallocTotalBytes)
+	}
+	if meminfo.VmallocUsedBytes != nil {
+		metrics["VmallocUsed_bytes"] = float64(*meminfo.VmallocUsedBytes)
+	}
+	if meminfo.WritebackBytes != nil {
+		metrics["Writeback_bytes"] = float64(*meminfo.WritebackBytes)
+	}
+	if meminfo.WritebackTmpBytes != nil {
+		metrics["WritebackTmp_bytes"] = float64(*meminfo.WritebackTmpBytes)
+	}
+
+	// These fields are always in bytes and do not have `Bytes`
+	// suffixed counterparts in the procfs.Meminfo struct, nor do
+	// they have `_bytes` suffix on the metric names.
+	if meminfo.HugePagesFree != nil {
+		metrics["HugePages_Free"] = float64(*meminfo.HugePagesFree)
+	}
+	if meminfo.HugePagesRsvd != nil {
+		metrics["HugePages_Rsvd"] = float64(*meminfo.HugePagesRsvd)
+	}
+	if meminfo.HugePagesSurp != nil {
+		metrics["HugePages_Surp"] = float64(*meminfo.HugePagesSurp)
+	}
+	if meminfo.HugePagesTotal != nil {
+		metrics["HugePages_Total"] = float64(*meminfo.HugePagesTotal)
+	}
+
+	return metrics, nil
 }
--- a/collector/meminfo_linux_test.go
+++ b/collector/meminfo_linux_test.go
@ -19,18 +19,22 @@ package collector
 import (
 	"os"
 	"testing"
+
+	"github.com/go-kit/log"
 )

 func TestMemInfo(t *testing.T) {
-	file, err := os.Open("fixtures/proc/meminfo")
-	if err != nil {
-		t.Fatal(err)
-	}
-	defer file.Close()
+	*procPath = "fixtures/proc"
+	logger := log.NewLogfmtLogger(os.Stderr)

-	memInfo, err := parseMemInfo(file)
+	collector, err := NewMeminfoCollector(logger)
 	if err != nil {
-		t.Fatal(err)
+		panic(err)
+	}
+
+	memInfo, err := collector.(*meminfoCollector).getMemInfo()
+	if err != nil {
+		panic(err)
 	}

 	if want, got := 3831959552.0, memInfo["MemTotal_bytes"]; want != got {
--- a/collector/meminfo_netbsd.go
+++ b/collector/meminfo_netbsd.go
@ -17,9 +17,21 @@
 package collector

 import (
+	"github.com/go-kit/log"
 	"golang.org/x/sys/unix"
 )

+type meminfoCollector struct {
+	logger log.Logger
+}
+
+// NewMeminfoCollector returns a new Collector exposing memory stats.
+func NewMeminfoCollector(logger log.Logger) (Collector, error) {
+	return &meminfoCollector{
+		logger: logger,
+	}, nil
+}
+
 func (c *meminfoCollector) getMemInfo() (map[string]float64, error) {
 	uvmexp, err := unix.SysctlUvmexp("vm.uvmexp2")
 	if err != nil {
--- a/collector/meminfo_openbsd.go
+++ b/collector/meminfo_openbsd.go
@ -18,6 +18,8 @@ package collector

 import (
 	"fmt"
+
+	"github.com/go-kit/log"
 )

 /*
@ -53,6 +55,17 @@ sysctl_bcstats(struct bcachestats *bcstats)
 */
 import "C"

+type meminfoCollector struct {
+	logger log.Logger
+}
+
+// NewMeminfoCollector returns a new Collector exposing memory stats.
+func NewMeminfoCollector(logger log.Logger) (Collector, error) {
+	return &meminfoCollector{
+		logger: logger,
+	}, nil
+}
+
 func (c *meminfoCollector) getMemInfo() (map[string]float64, error) {
 	var uvmexp C.struct_uvmexp
 	var bcstats C.struct_bcachestats
--- a/collector/meminfo_openbsd_amd64.go
+++ b/collector/meminfo_openbsd_amd64.go
@ -17,8 +17,10 @@
 package collector

 import (
-	"golang.org/x/sys/unix"
 	"unsafe"
+
+	"github.com/go-kit/log"
+	"golang.org/x/sys/unix"
 )

 const (
@ -48,6 +50,17 @@ type bcachestats struct {
 	Dmaflips       int64
 }

+type meminfoCollector struct {
+	logger log.Logger
+}
+
+// NewMeminfoCollector returns a new Collector exposing memory stats.
+func NewMeminfoCollector(logger log.Logger) (Collector, error) {
+	return &meminfoCollector{
+		logger: logger,
+	}, nil
+}
+
 func (c *meminfoCollector) getMemInfo() (map[string]float64, error) {
 	uvmexpb, err := unix.SysctlRaw("vm.uvmexp")
 	if err != nil {