Replace custom debugging technique (#51)

Signed-off-by: Florian Lehner <[email protected]>

cli_flags.go

@@ -70,6 +70,7 @@ var (
 		tracer.ProbabilisticThresholdMax-1, tracer.ProbabilisticThresholdMax-1)
 	probabilisticIntervalHelp = "Time interval for which probabilistic profiling will be " +
 		"enabled or disabled."
+	pprofHelp = "Listening address (e.g. localhost:6060) to serve pprof information."
 )
 
 // Variables for command line arguments
@@ -92,6 +93,7 @@ var (
 	argMapScaleFactor         uint
 	argProbabilisticThreshold uint
 	argProbabilisticInterval  time.Duration
+	argPprofAddr              string
 
 	// "internal" flag variables.
 	// Flag variables that are configured in "internal" builds will have to be assigned
@@ -131,6 +133,8 @@ func parseArgs() error {
 
 	fs.UintVar(&argProjectID, "project-id", 1, projectIDHelp)
 
+	fs.StringVar(&argPprofAddr, "pprof", "", pprofHelp)
+
 	// Using a default value here to simplify OTEL review process.
 	fs.StringVar(&argSecretToken, "secret-token", "abc123", secretTokenHelp)
 

main.go

@@ -9,11 +9,15 @@ package main
 import (
 	"context"
 	"fmt"
+	"net/http"
 	"os"
 	"os/signal"
 	"runtime"
 	"time"
 
+	//nolint:gosec
+	_ "net/http/pprof"
+
 	"github.com/elastic/otel-profiling-agent/containermetadata"
 	"github.com/elastic/otel-profiling-agent/vc"
 	"golang.org/x/sys/unix"
@@ -33,8 +37,6 @@ import (
 	"github.com/elastic/otel-profiling-agent/tracer"
 
 	log "github.com/sirupsen/logrus"
-
-	"github.com/elastic/otel-profiling-agent/memorydebug"
 )
 
 // Short copyright / license text for eBPF code
@@ -122,6 +124,15 @@ func mainWithExitCode() exitCode {
 		unix.SIGINT, unix.SIGTERM, unix.SIGABRT)
 	defer mainCancel()
 
+	if argPprofAddr != "" {
+		go func() {
+			//nolint:gosec
+			if err = http.ListenAndServe(argPprofAddr, nil); err != nil {
+				log.Errorf("Serving pprof on %s failed: %s", argPprofAddr, err)
+			}
+		}()
+	}
+
 	// Sanity check for probabilistic profiling arguments
 	if argProbabilisticInterval < 1*time.Minute || argProbabilisticInterval > 5*time.Minute {
 		log.Error("Invalid argument for probabilistic-interval: use " +
@@ -145,11 +156,6 @@ func mainWithExitCode() exitCode {
 	log.Infof("Starting OTEL profiling agent %s (revision %s, build timestamp %s)",
 		vc.Version(), vc.Revision(), vc.BuildTimestamp())
 
-	// Enable dumping of full heaps if the size of the allocated Golang heap
-	// exceeds 150m, and start dumping memory profiles when the heap exceeds
-	// 250m (only in debug builds, go build -tags debug).
-	memorydebug.Init(1024*1024*250, 1024*1024*150)
-
 	if !argNoKernelVersionCheck {
 		var major, minor, patch uint32
 		major, minor, patch, err = tracer.GetCurrentKernelVersion()

processmanager/processinfo.go

@@ -30,7 +30,6 @@ import (
 	"github.com/elastic/otel-profiling-agent/libpf"
 	"github.com/elastic/otel-profiling-agent/libpf/pfelf"
 	"github.com/elastic/otel-profiling-agent/lpm"
-	"github.com/elastic/otel-profiling-agent/memorydebug"
 	"github.com/elastic/otel-profiling-agent/proc"
 	"github.com/elastic/otel-profiling-agent/process"
 	eim "github.com/elastic/otel-profiling-agent/processmanager/execinfomanager"
@@ -455,8 +454,6 @@ func (pm *ProcessManager) synchronizeMappings(pr process.Process,
 
 	// Add the new ELF mappings
 	for _, mapping := range mpAdd {
-		// Output memory usage in debug builds.
-		memorydebug.DebugLogMemoryUsage()
 		pm.processNewExecMapping(pr, mapping)
 	}
 

tracehandler/tracehandler.go

@@ -20,7 +20,6 @@ import (
 	"github.com/elastic/otel-profiling-agent/containermetadata"
 	"github.com/elastic/otel-profiling-agent/host"
 	"github.com/elastic/otel-profiling-agent/libpf"
-	"github.com/elastic/otel-profiling-agent/memorydebug"
 	"github.com/elastic/otel-profiling-agent/reporter"
 	"github.com/elastic/otel-profiling-agent/util"
 )
@@ -208,8 +207,6 @@ func Start(ctx context.Context, containerMetadataHandler containermetadata.Handl
 			case <-ctx.Done():
 				return
 			}
-			// Output memory usage in debug builds.
-			memorydebug.DebugLogMemoryUsage()
 		}
 	}()