diff --git a/.gitignore b/.gitignore
index b19a59c..dadd420 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,4 +2,4 @@
 cmake-get_encap_msg*
 cmake-build*
 get_encap_msg
-
+build/
diff --git a/src/Config.cpp b/src/Config.cpp
index c6b79db..da40f21 100644
--- a/src/Config.cpp
+++ b/src/Config.cpp
@@ -515,7 +515,6 @@ void Config::parse_grouping(const YAML::Node &node) {
 }
 
 Config::~Config() {
-    delete singleton_instance;
 }
 
 
diff --git a/src/Logger.cpp b/src/Logger.cpp
index 46d90c5..b0ea77e 100644
--- a/src/Logger.cpp
+++ b/src/Logger.cpp
@@ -92,8 +92,6 @@ Logger::Logger(const char *log_filename, const char *debug_filename) {
  * Destructor for class
  ***********************************************************************/
 Logger::~Logger() {
-    delete singleton_instance;
-
     /*
      * Close open files
      */
diff --git a/src/MessageBus.cpp b/src/MessageBus.cpp
index acce6db..7b56c10 100644
--- a/src/MessageBus.cpp
+++ b/src/MessageBus.cpp
@@ -47,7 +47,6 @@ MessageBus::MessageBus() {
 
 MessageBus::~MessageBus() {
     disconnect();
-    delete singleton_instance;
     delete producer_config;
     delete event_callback;
 }
diff --git a/src/SockBuffer.cpp b/src/SockBuffer.cpp
index eea6884..083d578 100644
--- a/src/SockBuffer.cpp
+++ b/src/SockBuffer.cpp
@@ -1,3 +1,4 @@
+
 /*
  * Copyright (c) 2013-2016 Cisco Systems, Inc. and others.  All rights reserved.
  * Copyright (c) 2019 Lumin Shi.  All rights reserved.
@@ -78,12 +79,18 @@ void SockBuffer::stop() {
 }
 
 void SockBuffer::save_data() {
+  int prc;
     if ((wrap_state and (write_position + 1) < read_position) or
         (not wrap_state and write_position < ring_buffer_size)) {
 
         // Attempt to read from socket
-        if (poll(&pfd_tcp, 1, 5)) {
+      prc = poll(&pfd_tcp, 1, 5);
+      if (prc < 0) {
+        LOG_ERR("tcp poll failed (%d)", errno);
+        throw "tcp poll failed";
+      } else if (prc > 0) {
             if (pfd_tcp.revents & POLLHUP or pfd_tcp.revents & POLLERR) {
+                LOG_INFO("peer closed tcp connection");
                 bytes_read = 0;  // Indicate to close the connection
             } else {
                 if (not wrap_state) {
@@ -108,7 +115,14 @@ void SockBuffer::save_data() {
                 close(writer_fd);
                 close(reader_fd);
                 close(router_tcp_fd);
-                throw "bad tcp connection.";
+                if (bytes_read < 0) {
+                  LOG_ERR("tcp read failed: %d", errno);
+                  throw "tcp read failed";
+                } else {
+                  LOG_INFO("tcp connection eof");
+                  running = false;
+                  return;
+                }
             }
             else {
                 sock_buf_write_ptr += bytes_read;
@@ -222,8 +236,9 @@ void SockBuffer::sock_bufferer() {
         try {
             save_data();
             push_data();
-        } catch (...) {
-            LOG_INFO("%s: Thread for sock [%d] ended abnormally: ", router_ip.c_str(), router_tcp_fd);
+        } catch (const char *err) {
+          LOG_ERR("%s: Thread for sock [%d] ended abnormally: %s",
+                   router_ip.c_str(), router_tcp_fd, err);
             // set running to false to exit the while loop.
             running = false;
         }
diff --git a/src/Worker.cpp b/src/Worker.cpp
index ac87edb..8d7ec85 100644
--- a/src/Worker.cpp
+++ b/src/Worker.cpp
@@ -207,7 +207,7 @@ void Worker::refill_buffer(int recv_len) {
         received_bytes = recv(reader_fd,get_unread_buffer() + get_bmp_data_unread_len(),
                 recv_len,MSG_WAITALL);
         if (received_bytes <= 0) {
-            LOG_INFO("bad connection");
+            LOG_INFO("sock_buffer terminated, worker stopping");
             // set worker status to stopped. the main thread will clean up later.
             status = WORKER_STATUS_STOPPED;
         }