internal/cli: add skiptrace flag for profiling (#715)

* internal/cli: add skiptrace flag

* docs: update docs for skiptrace flag

docs/cli/debug_pprof.md

@@ -6,6 +6,8 @@ The ```debug pprof <enode>``` command will create an archive containing bor ppro
 
 - ```address```: Address of the grpc endpoint (default: 127.0.0.1:3131)
 
-- ```seconds```: seconds to trace (default: 2)
+- ```seconds```: seconds to profile (default: 2)
 
 - ```output```: Output directory
+
+- ```skiptrace```: Skip running the trace (default: false)

internal/cli/debug_pprof.go

@@ -18,6 +18,7 @@ type DebugPprofCommand struct {
 
 	seconds   uint64
 	output    string
+	skiptrace bool
 }
 
 func (p *DebugPprofCommand) MarkDown() string {
@@ -44,7 +45,7 @@ func (d *DebugPprofCommand) Flags() *flagset.Flagset {
 
 	flags.Uint64Flag(&flagset.Uint64Flag{
 		Name:    "seconds",
-		Usage:   "seconds to trace",
+		Usage:   "seconds to profile",
 		Value:   &d.seconds,
 		Default: 2,
 	})
@@ -54,6 +55,15 @@ func (d *DebugPprofCommand) Flags() *flagset.Flagset {
 		Usage: "Output directory",
 	})
 
+	// Trace profiles can be expensive and take too much size (for grpc).
+	// This flag will help in making it optional.
+	flags.BoolFlag(&flagset.BoolFlag{
+		Name:    "skiptrace",
+		Value:   &d.skiptrace,
+		Usage:   "Skip running the trace",
+		Default: false,
+	})
+
 	return flags
 }
 
@@ -119,11 +129,16 @@ func (d *DebugPprofCommand) Run(args []string) int {
 	ctx, cancelFn := context.WithCancel(context.Background())
 	trapSignal(cancelFn)
 
+	// Only take cpu and heap profiles by default
 	profiles := map[string]string{
 		"heap": "heap",
 		"cpu":  "cpu",
-		"trace": "trace",
 	}
+
+	if !d.skiptrace {
+		profiles["trace"] = "trace"
+	}
+
 	for profile, filename := range profiles {
 		if err := pprofProfile(ctx, profile, filename); err != nil {
 			d.UI.Error(fmt.Sprintf("Error creating profile '%s': %v", profile, err))