diff --git a/libtransport/NetworkPluginServer.cpp b/libtransport/NetworkPluginServer.cpp
index ee72c3e11eb3826b71d32ffe4f86c4cfae07aae2..2bec00a2182c8ec0bd1675d8bf196d402a8d789c 100644
--- a/libtransport/NetworkPluginServer.cpp
+++ b/libtransport/NetworkPluginServer.cpp
@@ -1305,6 +1305,7 @@ void NetworkPluginServer::send(boost::shared_ptr<Swift::Connection> &c, const st
 }
 
 void NetworkPluginServer::pingTimeout() {
+	LOG4CXX_INFO(logger, "Sending PING to backends");
 	// TODO: move to separate timer, those 2 loops could be expensive
 	// Some users are connected for weeks and they are blocking backend to be destroyed and its memory
 	// to be freed. We are finding users who are inactive for more than "idle_reconnect_time" seconds and
@@ -1350,6 +1351,9 @@ void NetworkPluginServer::pingTimeout() {
 			if ((*it)->pongReceived) {
 				sendPing((*it));
 			}
+			else {
+				LOG4CXX_INFO(logger, "Tried to send PING to backend without pongReceived= " << (*it)->pongReceived << ": (ID=" << (*it)->id << ")");
+			}
 		}
 		else {
 			LOG4CXX_INFO(logger, "Disconnecting backend " << (*it) << " (ID=" << (*it)->id << "). PING response not received.");
@@ -1966,6 +1970,9 @@ void NetworkPluginServer::sendPing(Backend *c) {
 		send(c->connection, message);
 		c->pongReceived = false;
 	}
+	else {
+		LOG4CXX_WARN(logger, "Tried to send PING to backend without connection: " << c << " (ID=" << c->id << ")");
+	}
 // 	LOG4CXX_INFO(logger, "PING to " << c);
 }