[receiver/hostmetrics] Cheaper parent PID and number of threads retrieval on Windows

receiver/hostmetricsreceiver/internal/scraper/processscraper/config.go

@@ -20,6 +20,9 @@ type Config struct {
 	Include MatchConfig `mapstructure:"include"`
 	Exclude MatchConfig `mapstructure:"exclude"`
 
+	// Exclude getting the parent process ID since it can be a costly operation on Windows.
+	ExcludeParentPid bool `mapstructure:"exclude_parent_pid,omitempty"`
+
 	// MuteProcessAllErrors is a flag that will mute all the errors encountered when trying to read metrics of a process.
 	// When this flag is enabled, there is no need to activate any other error suppression flags.
 	MuteProcessAllErrors bool `mapstructure:"mute_process_all_errors,omitempty"`

receiver/hostmetricsreceiver/internal/scraper/processscraper/get_process_handles_windows.go

@@ -0,0 +1,55 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+//go:build windows
+
+package processscraper // import "github.com/open-telemetry/opentelemetry-collector-contrib/receiver/hostmetricsreceiver/internal/scraper/processscraper"
+
+import (
+	"context"
+	"fmt"
+	"unsafe"
+
+	"github.com/shirou/gopsutil/v4/process"
+	"golang.org/x/sys/windows"
+)
+
+func getProcessHandlesInternalNew(ctx context.Context) (processHandles, error) {
+	snap, err := windows.CreateToolhelp32Snapshot(windows.TH32CS_SNAPPROCESS, 0)
+	if err != nil {
+		return nil, fmt.Errorf("could not create snapshot: %w", err)
+	}
+	defer func() {
+		_ = windows.CloseHandle(snap)
+	}()
+
+	var pe32 windows.ProcessEntry32
+	pe32.Size = uint32(unsafe.Sizeof(pe32))
+	if err = windows.Process32First(snap, &pe32); err != nil {
+		return nil, fmt.Errorf("could not get first process: %w", err)
+	}
+
+	wrappedProcesses := make([]wrappedProcessHandle, 0, 64)
+	for {
+		select {
+		case <-ctx.Done():
+			return nil, ctx.Err()
+		default:
+			p, _ := process.NewProcess(int32(pe32.ProcessID))
+			if p != nil {
+				wrappedProcess := wrappedProcessHandle{
+					Process: p,
+					ppid:    int32(pe32.ParentProcessID),
+					threads: int32(pe32.Threads),
+				}
+				wrappedProcesses = append(wrappedProcesses, wrappedProcess)
+			}
+		}
+
+		if err = windows.Process32Next(snap, &pe32); err != nil {
+			break
+		}
+	}
+
+	return &gopsProcessHandles{handles: wrappedProcesses}, nil
+}

receiver/hostmetricsreceiver/internal/scraper/processscraper/process.go

@@ -118,6 +118,8 @@ func (p *gopsProcessHandles) Len() int {
 
 type wrappedProcessHandle struct {
 	*process.Process
+	ppid    int32
+	threads int32
 }
 
 func (p wrappedProcessHandle) CgroupWithContext(ctx context.Context) (string, error) {
@@ -131,6 +133,28 @@ func (p wrappedProcessHandle) CgroupWithContext(ctx context.Context) (string, er
 	return strings.TrimSuffix(string(contents), "\n"), nil
 }
 
+func (p wrappedProcessHandle) PpidWithContext(ctx context.Context) (int32, error) {
+	if p.ppid == -1 {
+		ppid, err := p.Process.PpidWithContext(ctx)
+		if err != nil {
+			return 0, err
+		}
+		p.ppid = ppid
+	}
+	return p.ppid, nil
+}
+
+func (p wrappedProcessHandle) NumThreadsWithContext(ctx context.Context) (int32, error) {
+	if p.threads == -1 {
+		threads, err := p.Process.NumThreadsWithContext(ctx)
+		if err != nil {
+			return 0, err
+		}
+		p.threads = threads
+	}
+	return p.threads, nil
+}
+
 // copied from gopsutil:
 // GetEnvWithContext retrieves the environment variable key. If it does not exist it returns the default.
 // The context may optionally contain a map superseding os.EnvKey.
@@ -157,7 +181,11 @@ func getProcessHandlesInternal(ctx context.Context) (processHandles, error) {
 	}
 	wrapped := make([]wrappedProcessHandle, len(processes))
 	for i, p := range processes {
-		wrapped[i] = wrappedProcessHandle{Process: p}
+		wrapped[i] = wrappedProcessHandle{
+			Process: p,
+			ppid:    -1,
+			threads: -1,
+		}
 	}
 
 	return &gopsProcessHandles{handles: wrapped}, nil

receiver/hostmetricsreceiver/internal/scraper/processscraper/process_metadata_benchmark_test.go

@@ -0,0 +1,67 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+//go:build windows
+
+package processscraper
+
+import (
+	"context"
+	"testing"
+
+	"go.opentelemetry.io/collector/scraper"
+)
+
+func BenchmarkGetProcessMetadata(b *testing.B) {
+	ctx := context.Background()
+	config := &Config{
+		MuteProcessExeError:  true,
+		MuteProcessNameError: true,
+		ExcludeParentPid:     true,
+		MuteProcessAllErrors: true, // Only way to pass the benchmark
+	}
+
+	scraper, err := newProcessScraper(scraper.Settings{}, config)
+	if err != nil {
+		b.Fatalf("Failed to create process scraper: %v", err)
+	}
+
+	benchmarks := []struct {
+		name             string
+		getFunc          func(context.Context) (processHandles, error)
+		excludeParentPid bool
+	}{
+		{
+			name:    "Old-IncludeParentPid",
+			getFunc: getProcessHandlesInternal,
+		},
+		{
+			name:    "New-IncludeParentPid",
+			getFunc: getProcessHandlesInternalNew,
+		},
+		{
+			name:             "Old-ExcludeParentPid",
+			getFunc:          getProcessHandlesInternal,
+			excludeParentPid: true,
+		},
+		{
+			name:             "New-ExcludeParentPid",
+			getFunc:          getProcessHandlesInternalNew,
+			excludeParentPid: true,
+		},
+	}
+
+	for _, bm := range benchmarks {
+		b.Run(bm.name, func(b *testing.B) {
+			scraper.getProcessHandles = bm.getFunc
+			scraper.config.ExcludeParentPid = bm.excludeParentPid
+
+			for i := 0; i < b.N; i++ {
+				_, err := scraper.getProcessMetadata(ctx)
+				if err != nil {
+					b.Fatalf("Failed to get process metadata: %v", err)
+				}
+			}
+		})
+	}
+}

receiver/hostmetricsreceiver/internal/scraper/processscraper/process_scraper.go

@@ -250,7 +250,7 @@ func (s *processScraper) getProcessMetadata(ctx context.Context) ([]*processMeta
 		}
 
 		command, err := getProcessCommand(ctx, handle)
-		if err != nil {
+		if err != nil && !s.config.MuteProcessAllErrors {
 			errs.AddPartial(0, fmt.Errorf("error reading command for process %q (pid %v): %w", executable.name, pid, err))
 		}
 
@@ -271,14 +271,17 @@ func (s *processScraper) getProcessMetadata(ctx context.Context) ([]*processMeta
 			continue
 		}
 
-		parentPid, err := parentPid(ctx, handle, pid)
-		if err != nil {
-			errs.AddPartial(0, fmt.Errorf("error reading parent pid for process %q (pid %v): %w", executable.name, pid, err))
+		parentProcessID := int32(0)
+		if !s.config.ExcludeParentPid {
+			parentProcessID, err = parentPid(ctx, handle, pid)
+			if err != nil {
+				errs.AddPartial(0, fmt.Errorf("error reading parent pid for process %q (pid %v): %w", executable.name, pid, err))
+			}
 		}
 
 		md := &processMetadata{
 			pid:        pid,
-			parentPid:  parentPid,
+			parentPid:  parentProcessID,
 			executable: executable,
 			command:    command,
 			username:   username,