diff --git a/demo/paho/paho.c b/demo/paho/paho.c
index 2a944ca4..c5c6610a 100644
--- a/demo/paho/paho.c
+++ b/demo/paho/paho.c
@@ -133,6 +133,9 @@ int main(int argc, char* argv[])
 	int rc;
 	int ch;
 
+	// nng_log_set_logger(nng_system_logger);
+	nng_log_set_logger(nng_stderr_logger);
+	nng_log_set_level(NNG_LOG_DEBUG);
 	if ((rc = MQTTAsync_create(&client, ADDRESS, CLIENTID, MQTTCLIENT_PERSISTENCE_NONE, NULL))
 			!= MQTTASYNC_SUCCESS)
 	{
diff --git a/src/core/dialer.c b/src/core/dialer.c
index 50690a20..9476436d 100644
--- a/src/core/dialer.c
+++ b/src/core/dialer.c
@@ -276,6 +276,10 @@ nni_dialer_create(nni_dialer **dp, nni_sock *s, const char *url_str)
 		nni_stat_unregister(&d->st_root);
 #endif
 		nni_dialer_destroy(d);
+		nng_log_warn("NanoSDK-CONN-FAIL",
+		    "Fail to create the dialer of socket<%u> to %s: %s",
+		    nni_sock_id(d->d_sock), d->d_url->u_rawurl,
+		    nng_strerror(rv));
 		return (rv);
 	}
 
@@ -342,6 +346,8 @@ nni_dialer_close(nni_dialer *d)
 		nni_dialer_rele(d);
 		return;
 	}
+	nng_log_debug("NanoSDK-Dialer",
+		    "Dialer to %s is being closed", d->d_url->u_rawurl);
 	d->d_closed = true;
 	nni_id_remove(&dialers, d->d_id);
 	nni_mtx_unlock(&dialers_lk);
@@ -358,6 +364,9 @@ dialer_timer_cb(void *arg)
 	nni_dialer *d = arg;
 
 	if (nni_aio_result(&d->d_tmo_aio) == 0) {
+		nng_log_info("NanoSDK-Timer",
+		    "socket<%u> to %s is reconnecting ...",
+		    nni_sock_id(d->d_sock), d->d_url->u_rawurl);
 		dialer_connect_start(d);
 	}
 }
@@ -385,11 +394,15 @@ dialer_connect_cb(void *arg)
 	case NNG_ECLOSED:   // No further action.
 	case NNG_ECANCELED: // No further action.
 		nni_dialer_bump_error(d, rv);
+		nng_log_warn("NanoSDK-CONN-FAIL",
+		    "socket<%u> to %s is being closed: %s",
+		    nni_sock_id(d->d_sock), d->d_url->u_rawurl,
+		    nng_strerror(rv));
 		break;
 	case NNG_ECONNREFUSED:
 	case NNG_ETIMEDOUT:
 	default:
-		nng_log_warn("NNG-CONN-FAIL",
+		nng_log_warn("NanoSDK-CONN-FAIL",
 		    "Failed connecting socket<%u> to %s: %s",
 		    nni_sock_id(d->d_sock), d->d_url->u_rawurl,
 		    nng_strerror(rv));
@@ -410,6 +423,8 @@ dialer_connect_cb(void *arg)
 static void
 dialer_connect_start(nni_dialer *d)
 {
+	nng_log_info("NanoSDK-DIAL", "Starting Connecting for socket<%u> on %s",
+	    nni_sock_id(d->d_sock), d->d_url->u_rawurl);
 	d->d_ops.d_connect(d->d_data, &d->d_con_aio);
 }
 
@@ -456,6 +471,8 @@ nni_dialer_stop(nni_dialer *d)
 	nni_aio_stop(&d->d_tmo_aio);
 	nni_aio_stop(&d->d_con_aio);
 	d->d_ops.d_close(d->d_data);
+	nng_log_info("NanoSDK-DIAL", "Stopping dialer for socket<%u> on %s",
+	    nni_sock_id(d->d_sock), d->d_url->u_rawurl);
 }
 
 nni_sock *
diff --git a/src/mqtt/transport/tcp/mqtt_tcp.c b/src/mqtt/transport/tcp/mqtt_tcp.c
index 9bee27fc..43aa93e2 100644
--- a/src/mqtt/transport/tcp/mqtt_tcp.c
+++ b/src/mqtt/transport/tcp/mqtt_tcp.c
@@ -1535,6 +1535,8 @@ mqtt_tcptran_ep_connect(void *arg, nni_aio *aio)
 		ep->backoff = ep->backoff > ep->backoff_max
 		    ? (nni_duration) (nni_random() % 1000)
 		    : ep->backoff;
+		nng_log_debug("NanoSDK-Transport",
+		    "wait backoff time : %ld ms to start reconnect ... ", ep->backoff);
 		nni_msleep(ep->backoff);
 	} else {
 		ep->backoff = nni_random()%2000;
diff --git a/src/platform/posix/posix_tcpconn.c b/src/platform/posix/posix_tcpconn.c
index ff8031ff..cf7fadfc 100644
--- a/src/platform/posix/posix_tcpconn.c
+++ b/src/platform/posix/posix_tcpconn.c
@@ -71,6 +71,8 @@ tcp_dowrite(nni_tcp_conn *c)
 			case EINTR:
 				continue;
 			case EAGAIN:
+				nng_log_info("NanoSDK-POSIX-TCP",
+		    	"Socket %d is congested %d",fd, nni_plat_errno(errno));
 #ifdef EWOULDBLOCK
 #if EWOULDBLOCK != EAGAIN
 			case EWOULDBLOCK:
@@ -78,9 +80,10 @@ tcp_dowrite(nni_tcp_conn *c)
 #endif
 				return;
 			default:
+				nng_log_info("NanoSDK-POSIX-TCP",
+				    "sendmsg to Socket %d fail %d",fd, nni_plat_errno(errno));
 				nni_aio_list_remove(aio);
-				nni_aio_finish_error(
-				    aio, nni_plat_errno(errno));
+				nni_aio_finish_error(aio, nni_plat_errno(errno));
 				return;
 			}
 		}
@@ -133,8 +136,12 @@ tcp_doread(nni_tcp_conn *c)
 			case EINTR:
 				continue;
 			case EAGAIN:
+				nng_log_debug("NanoSDK-POSIX-TCP",
+		    	"Reading Socket %d return EAGAIN %d",fd, nni_plat_errno(errno));
 				return;
 			default:
+				nng_log_info("NanoSDK-POSIX-TCP",
+				    "readv of Socket %d fail %d",fd, nni_plat_errno(errno));
 				nni_aio_list_remove(aio);
 				nni_aio_finish_error(
 				    aio, nni_plat_errno(errno));
@@ -145,6 +152,8 @@ tcp_doread(nni_tcp_conn *c)
 		if (n == 0) {
 			// No bytes indicates a closed descriptor.
 			// This implicitly completes this (all!) aio.
+			nng_log_info("NanoSDK-POSIX-TCP",
+		    	"Reading Socket %d hits EOF",fd);
 			nni_aio_list_remove(aio);
 			nni_aio_finish_error(aio, NNG_ECONNSHUT);
 			continue;
diff --git a/src/sp/transport.c b/src/sp/transport.c
index 8939438d..a6f09a69 100644
--- a/src/sp/transport.c
+++ b/src/sp/transport.c
@@ -25,7 +25,7 @@ nni_sp_tran_register(nni_sp_tran *tran)
 	if (!nni_list_node_active(&tran->tran_link)) {
 		tran->tran_init();
 		nni_list_append(&sp_tran_list, tran);
-		nng_log_info(
+		nng_log_debug(
 		    "NanoSDK-TRAN", "Registered transport: %s", tran->tran_scheme);
 	}
 	nni_rwlock_unlock(&sp_tran_lk);
diff --git a/src/supplemental/mqtt/mqtt_nano_paho.c b/src/supplemental/mqtt/mqtt_nano_paho.c
index eba96fb5..39e8a5e6 100644
--- a/src/supplemental/mqtt/mqtt_nano_paho.c
+++ b/src/supplemental/mqtt/mqtt_nano_paho.c
@@ -537,7 +537,7 @@ connect_cb(nng_pipe p, nng_pipe_ev ev, void *arg)
 	// get property for MQTT V5
 	// property *prop;
 	// nng_pipe_get_ptr(p, NNG_OPT_MQTT_CONNECT_PROPERTY, &prop);
-    nng_log_warn("Connected!", "This is also fine");
+    nng_log_warn("NanoSDK-Internal!", "Pipe is Connected");
     if (reason == MQTTREASONCODE_SUCCESS) {
         m->shouldBeConnected = 1;
         if (m->connect.onSuccess) {