Add support for pprof in harmony + node.sh (#2424)

cmd/harmony/main.go

@@ -6,6 +6,8 @@ import (
 	"io/ioutil"
 	"math/big"
 	"math/rand"
+	"net/http"
+	_ "net/http/pprof"
 	"os"
 	"os/signal"
 	"path"
@@ -87,6 +89,7 @@ var (
 	freshDB          = flag.Bool("fresh_db", false, "true means the existing disk based db will be removed")
 	profile          = flag.Bool("profile", false, "Turn on profiling (CPU, Memory).")
 	metricsReportURL = flag.String("metrics_report_url", "", "If set, reports metrics to this URL.")
+	pprof            = flag.String("pprof", "", "what address and port the pprof profiling server should listen on")
 	versionFlag      = flag.Bool("version", false, "Output version info")
 	onlyLogTps       = flag.Bool("only_log_tps", false, "Only log TPS if true")
 	dnsZone          = flag.String("dns_zone", "", "if given and not empty, use peers from the zone (default: use libp2p peer discovery instead)")
@@ -164,6 +167,12 @@ var (
 )
 
 func initSetup() {
+
+	// Setup pprof
+	if addr := *pprof; addr != "" {
+		go func() { http.ListenAndServe(addr, nil) }()
+	}
+
 	// maybe request passphrase for bls key.
 	if *cmkEncryptedBLSKey == "" {
 		passphraseForBls()

scripts/node.sh

@@ -122,6 +122,7 @@ usage: ${progname} [-1ch] [-k KEYFILE]
    -M             support multi-key mode (default: off)
    -A             enable archival node mode (default: off)
    -R tracefile   enable p2p trace using tracefile (default: off)
+   -r address     start a pprof profiling server listening on the specified address
 
 examples:
 
@@ -168,6 +169,7 @@ shard_id=1
 download_harmony_db=false
 public_rpc=false
 blacklist=./.hmy/blacklist.txt
+pprof=""
 static=false
 multi_key=false
 archival=false
@@ -177,7 +179,7 @@ ${TRACEFILE=}
 
 unset OPTIND OPTARG opt
 OPTIND=1
-while getopts :1chk:sSp:dDmN:tT:i:ba:U:PvVIMB:AYR: opt
+while getopts :1chk:sSp:dDmN:tT:i:ba:U:PvVIMB:AYR:r: opt
 do
    case "${opt}" in
    '?') usage "unrecognized option -${OPTARG}";;
@@ -203,6 +205,7 @@ do
    U) upgrade_rel="${OPTARG}";;
    P) public_rpc=true;;
    B) blacklist="${OPTARG}";;
+   r) pprof="${OPTARG}";;
    v) msg "version: $version"
       exit 0 ;;
    V) LD_LIBRARY_PATH=. ./harmony -version
@@ -684,6 +687,11 @@ do
       -public_rpc
       )
    fi
+   if [ ! -z "${pprof}" ]; then
+      args+=(
+      -pprof "${pprof}"
+      )
+   fi
 # backward compatible with older harmony node software
    case "${node_type}" in
    explorer)