allow limit to traced message

server/client.go

@@ -1010,8 +1010,15 @@ func (c *client) traceMsg(msg []byte) {
 	if !c.trace {
 		return
 	}
-	// FIXME(dlc), allow limits to printable payload.
-	c.Tracef("<<- MSG_PAYLOAD: [%q]", msg[:len(msg)-LEN_CR_LF])
+
+	origLength := len(msg) - LEN_CR_LF
+	validLength := origLength
+	formatter := "<<- MSG_PAYLOAD: [%q]"
+	if origLength > c.srv.getOpts().MaxTracedMsgLen {
+		validLength = c.srv.getOpts().MaxTracedMsgLen
+		formatter = "<<- MSG_PAYLOAD: [\"%s...\"]"
+	}
+	c.Tracef(formatter, msg[:validLength])
 }
 
 func (c *client) traceInOp(op string, arg []byte) {

server/const.go

@@ -163,4 +163,7 @@ const (
 	// DEFAULT_RTT_MEASUREMENT_INTERVAL is how often we want to measure RTT from
 	// this server to clients, routes, gateways or leafnode connections.
 	DEFAULT_RTT_MEASUREMENT_INTERVAL = time.Hour
+
+	// MAX_TRACED_MSG_LEN is the maximum printable length for traced messages.
+	MAX_TRACED_MSG_LEN = 1024
 )

server/opts.go

@@ -190,6 +190,8 @@ type Options struct {
 	WriteDeadline    time.Duration `json:"-"`
 	MaxClosedClients int           `json:"-"`
 	LameDuckDuration time.Duration `json:"-"`
+	// MaxTracedMsgLen is the maximum printable length for traced messages.
+	MaxTracedMsgLen int `json:"max_traced_msg_len"`
 
 	// Operating a trusted NATS server
 	TrustedKeys      []string              `json:"-"`
@@ -539,6 +541,8 @@ func (o *Options) ProcessConfigFile(configFile string) error {
 			o.MaxPending = v.(int64)
 		case "max_connections", "max_conn":
 			o.MaxConn = int(v.(int64))
+		case "max_traced_msg_len":
+			o.MaxTracedMsgLen = int(v.(int64))
 		case "max_subscriptions", "max_subs":
 			o.MaxSubs = int(v.(int64))
 		case "ping_interval":
@@ -2482,6 +2486,9 @@ func setBaselineOptions(opts *Options) {
 	if opts.ReconnectErrorReports == 0 {
 		opts.ReconnectErrorReports = DEFAULT_RECONNECT_ERROR_REPORTS
 	}
+	if opts.MaxTracedMsgLen == -1 {
+		opts.MaxTracedMsgLen = MAX_TRACED_MSG_LEN
+	}
 }
 
 // ConfigureOptions accepts a flag set and augment it with NATS Server
@@ -2551,6 +2558,7 @@ func ConfigureOptions(fs *flag.FlagSet, args []string, printVersion, printHelp,
 	fs.StringVar(&opts.TLSCert, "tlscert", "", "Server certificate file.")
 	fs.StringVar(&opts.TLSKey, "tlskey", "", "Private key for server certificate.")
 	fs.StringVar(&opts.TLSCaCert, "tlscacert", "", "Client certificate CA for verification.")
+	fs.IntVar(&opts.MaxTracedMsgLen, "max_traced_msg_len", -1, "Maximum printable length for traced messages")
 
 	// The flags definition above set "default" values to some of the options.
 	// Calling Parse() here will override the default options with any value

server/opts_test.go

@@ -61,6 +61,7 @@ func TestDefaultOptions(t *testing.T) {
 		},
 		ConnectErrorReports:   DEFAULT_CONNECT_ERROR_REPORTS,
 		ReconnectErrorReports: DEFAULT_RECONNECT_ERROR_REPORTS,
+		MaxTracedMsgLen:       MAX_TRACED_MSG_LEN,
 	}
 
 	opts := &Options{}