diff --git a/CMakeLists.txt b/CMakeLists.txt
index f4422ee..d417550 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -86,15 +86,6 @@ ENDIF()
 
 find_package(OpenSSL)
 
-IF(APPLE)
-  # As of 10.10 yosemite, the OpenSSL static libraries shipped with os x have a dependency
-  # on zlib, so any time you link in openssl you also need to link zlib.  .  We really want to detect whether openssl was configured with the --no-zlib
-  # option or not when it was built, but that's difficult to do in practice, so we
-  # just always try to link it in on mac.
-  find_package( ZLIB REQUIRED )
-ENDIF(APPLE)
-
-
 set( CMAKE_FIND_LIBRARY_SUFFIXES ${ORIGINAL_LIB_SUFFIXES} )
 
 option( UNITY_BUILD OFF )
@@ -137,6 +128,7 @@ set( fc_sources
      src/log/appender.cpp
      src/log/console_appender.cpp
      src/log/file_appender.cpp
+     src/log/gelf_appender.cpp
      src/log/logger_config.cpp
      src/crypto/openssl.cpp
      src/crypto/aes.cpp
@@ -353,6 +345,14 @@ if(WIN32)
 
 endif(WIN32)
 
+IF(APPLE)
+  # As of 10.10 yosemite, the OpenSSL static libraries shipped with os x have a dependency
+  # on zlib, so any time you link in openssl you also need to link zlib.  .  We really want to detect whether openssl was configured with the --no-zlib
+  # option or not when it was built, but that's difficult to do in practice, so we
+  # just always try to link it in on mac.
+  find_package( ZLIB REQUIRED )
+ENDIF(APPLE)
+
 SET(OPENSSL_CONF_TARGET )
 IF(DEFINED CMAKE_RUNTIME_OUTPUT_DIRECTORY)
   SET (OPENSSL_CONF_TARGET ${CMAKE_RUNTIME_OUTPUT_DIRECTORY})
diff --git a/include/fc/exception/exception.hpp b/include/fc/exception/exception.hpp
index a3b26a0..1457214 100644
--- a/include/fc/exception/exception.hpp
+++ b/include/fc/exception/exception.hpp
@@ -298,21 +298,26 @@ namespace fc
  *  @brief Checks a condition and throws an assert_exception if the test is FALSE
  */
 #define FC_ASSERT( TEST, ... ) \
-   FC_EXPAND_MACRO( \
-      do { if( !(TEST) ) { FC_THROW_EXCEPTION( fc::assert_exception, #TEST ": "  __VA_ARGS__ ); } } while(0) \
-   )
+  FC_EXPAND_MACRO( \
+    FC_MULTILINE_MACRO_BEGIN \
+      if( !(TEST) ) \
+        FC_THROW_EXCEPTION( fc::assert_exception, #TEST ": "  __VA_ARGS__ ); \
+    FC_MULTILINE_MACRO_END \
+  )
 
 #define FC_CAPTURE_AND_THROW( EXCEPTION_TYPE, ... ) \
-   do { throw EXCEPTION_TYPE( FC_LOG_MESSAGE( error, "", FC_FORMAT_ARG_PARAMS(__VA_ARGS__) ) ); } while(0)
+  FC_MULTILINE_MACRO_BEGIN \
+    throw EXCEPTION_TYPE( FC_LOG_MESSAGE( error, "", FC_FORMAT_ARG_PARAMS(__VA_ARGS__) ) ); \
+  FC_MULTILINE_MACRO_END
 
 //#define FC_THROW( FORMAT, ... ) 
 // FC_INDIRECT_EXPAND workas around a bug in Visual C++ variadic macro processing that prevents it
 // from separating __VA_ARGS__ into separate tokens
 #define FC_INDIRECT_EXPAND(MACRO, ARGS) MACRO ARGS
 #define FC_THROW(  ... ) \
-   do { \
-   throw fc::exception( FC_INDIRECT_EXPAND(FC_LOG_MESSAGE, ( error, __VA_ARGS__ )) );  \
-   } while(0)
+  FC_MULTILINE_MACRO_BEGIN \
+    throw fc::exception( FC_INDIRECT_EXPAND(FC_LOG_MESSAGE, ( error, __VA_ARGS__ )) );  \
+  FC_MULTILINE_MACRO_END
 
 #define FC_EXCEPTION( EXCEPTION_TYPE, FORMAT, ... ) \
     EXCEPTION_TYPE( FC_LOG_MESSAGE( error, FORMAT, __VA_ARGS__ ) )  
@@ -322,9 +327,9 @@ namespace fc
  *  @param format - a const char* string with "${keys}"
  */
 #define FC_THROW_EXCEPTION( EXCEPTION, FORMAT, ... ) \
-   do { \
-   throw EXCEPTION( FC_LOG_MESSAGE( error, FORMAT, __VA_ARGS__ ) ); \
-   } while(0)
+  FC_MULTILINE_MACRO_BEGIN \
+    throw EXCEPTION( FC_LOG_MESSAGE( error, FORMAT, __VA_ARGS__ ) ); \
+  FC_MULTILINE_MACRO_END
 
 
 /**
@@ -332,10 +337,10 @@ namespace fc
  *  @brief Appends a log_message to the exception ER and rethrows it.
  */
 #define FC_RETHROW_EXCEPTION( ER, LOG_LEVEL, FORMAT, ... ) \
-  do { \
-     ER.append_log( FC_LOG_MESSAGE( LOG_LEVEL, FORMAT, __VA_ARGS__ ) ); \
-     throw;\
-  } while(0)
+  FC_MULTILINE_MACRO_BEGIN \
+    ER.append_log( FC_LOG_MESSAGE( LOG_LEVEL, FORMAT, __VA_ARGS__ ) ); \
+    throw; \
+  FC_MULTILINE_MACRO_END
 
 #define FC_LOG_AND_RETHROW( )  \
    catch( fc::exception& er ) { \
diff --git a/include/fc/filesystem.hpp b/include/fc/filesystem.hpp
index 4a05cd4..1a16926 100644
--- a/include/fc/filesystem.hpp
+++ b/include/fc/filesystem.hpp
@@ -1,5 +1,7 @@
 #pragma once
 #include <utility>
+#include <memory>
+
 #include <fc/string.hpp>
 #include <fc/reflect/typename.hpp>
 #include <fc/optional.hpp>
@@ -226,5 +228,37 @@ namespace fc {
      temp_directory(const fc::path& tempFolder = fc::temp_directory_path());
   };
 
+
+#if !defined(__APPLE__)
+  // this code is known to work on linux and windows.  It may work correctly on mac, 
+  // or it may need slight tweaks or extra includes.  It's disabled now to avoid giving
+  // a false sense of security.
+# define FC_HAS_SIMPLE_FILE_LOCK
+#endif
+#ifdef FC_HAS_SIMPLE_FILE_LOCK  
+  /** simple class which only allows one process to open any given file. 
+   * approximate usage:
+   * int main() {
+   *   fc::simple_file_lock instance_lock("~/.my_app/.lock");
+   *   if (!instance_lock.try_lock()) {
+   *     elog("my_app is already running");
+   *     return 1;
+   *   }
+   *   // do stuff here, file will be unlocked when instance_lock goes out of scope
+   * }
+  */
+  class simple_lock_file
+  {
+  public:
+    simple_lock_file(const path& lock_file_path);
+    ~simple_lock_file();
+    bool try_lock();
+    void unlock();
+  private:
+    class impl;
+    std::unique_ptr<impl> my;
+  };
+#endif // FC_HAS_SIMPLE_FILE_LOCK
+
 }
 
diff --git a/include/fc/log/gelf_appender.hpp b/include/fc/log/gelf_appender.hpp
new file mode 100644
index 0000000..2228313
--- /dev/null
+++ b/include/fc/log/gelf_appender.hpp
@@ -0,0 +1,32 @@
+#pragma once
+
+#include <fc/log/appender.hpp>
+#include <fc/log/logger.hpp>
+#include <fc/time.hpp>
+
+namespace fc 
+{
+  // Log appender that sends log messages in JSON format over UDP
+  // https://www.graylog2.org/resources/gelf/specification
+  class gelf_appender : public appender 
+  {
+  public:
+    struct config 
+    {
+      string endpoint = "127.0.0.1:12201";
+      string host = "fc"; // the name of the host, source or application that sent this message (just passed through to GELF server)
+    };
+
+    gelf_appender(const variant& args);
+    ~gelf_appender();
+    virtual void log(const log_message& m) override;
+
+  private:
+    class impl;
+    fc::shared_ptr<impl> my;
+  };
+} // namespace fc
+
+#include <fc/reflect/reflect.hpp>
+FC_REFLECT(fc::gelf_appender::config,
+           (endpoint)(host))
diff --git a/include/fc/log/logger.hpp b/include/fc/log/logger.hpp
index 7121d5f..9005d75 100644
--- a/include/fc/log/logger.hpp
+++ b/include/fc/log/logger.hpp
@@ -61,74 +61,77 @@ namespace fc
 #define DEFAULT_LOGGER
 #endif
 
-   
+// suppress warning "conditional expression is constant" in the while(0) for visual c++
+// http://cnicholson.net/2009/03/stupid-c-tricks-dowhile0-and-c4127/
+#define FC_MULTILINE_MACRO_BEGIN do {
+#ifdef _MSC_VER
+# define FC_MULTILINE_MACRO_END \
+    __pragma(warning(push)) \
+    __pragma(warning(disable:4127)) \
+    } while (0) \
+    __pragma(warning(pop))
+#else
+# define FC_MULTILINE_MACRO_END  } while (0)
+#endif
+
 #define fc_dlog( LOGGER, FORMAT, ... ) \
-  do { \
-   if( (LOGGER).is_enabled( fc::log_level::debug ) ) { \
+  FC_MULTILINE_MACRO_BEGIN \
+   if( (LOGGER).is_enabled( fc::log_level::debug ) ) \
       (LOGGER).log( FC_LOG_MESSAGE( debug, FORMAT, __VA_ARGS__ ) ); \
-   } \
-  } while (0)
+  FC_MULTILINE_MACRO_END
 
 #define fc_ilog( LOGGER, FORMAT, ... ) \
-  do { \
-   if( (LOGGER).is_enabled( fc::log_level::info ) ) { \
+  FC_MULTILINE_MACRO_BEGIN \
+   if( (LOGGER).is_enabled( fc::log_level::info ) ) \
       (LOGGER).log( FC_LOG_MESSAGE( info, FORMAT, __VA_ARGS__ ) ); \
-   } \
-  } while (0)
+  FC_MULTILINE_MACRO_END
 
 #define fc_wlog( LOGGER, FORMAT, ... ) \
-  do { \
-   if( (LOGGER).is_enabled( fc::log_level::warn ) ) { \
+  FC_MULTILINE_MACRO_BEGIN \
+   if( (LOGGER).is_enabled( fc::log_level::warn ) ) \
       (LOGGER).log( FC_LOG_MESSAGE( warn, FORMAT, __VA_ARGS__ ) ); \
-   } \
-  } while (0)
+  FC_MULTILINE_MACRO_END
 
 #define fc_elog( LOGGER, FORMAT, ... ) \
-  do { \
-   if( (LOGGER).is_enabled( fc::log_level::error ) ) { \
+  FC_MULTILINE_MACRO_BEGIN \
+   if( (LOGGER).is_enabled( fc::log_level::error ) ) \
       (LOGGER).log( FC_LOG_MESSAGE( error, FORMAT, __VA_ARGS__ ) ); \
-   } \
-  } while (0)
+  FC_MULTILINE_MACRO_END
 
 #define dlog( FORMAT, ... ) \
-  do { \
-   if( (fc::logger::get(DEFAULT_LOGGER)).is_enabled( fc::log_level::debug ) ) { \
+  FC_MULTILINE_MACRO_BEGIN \
+   if( (fc::logger::get(DEFAULT_LOGGER)).is_enabled( fc::log_level::debug ) ) \
       (fc::logger::get(DEFAULT_LOGGER)).log( FC_LOG_MESSAGE( debug, FORMAT, __VA_ARGS__ ) ); \
-   } \
-  } while (0)
+  FC_MULTILINE_MACRO_END
 
 /**
  * Sends the log message to a special 'user' log stream designed for messages that
  * the end user may like to see.
  */
 #define ulog( FORMAT, ... ) \
-  do { \
-   if( (fc::logger::get("user")).is_enabled( fc::log_level::debug ) ) { \
+  FC_MULTILINE_MACRO_BEGIN \
+   if( (fc::logger::get("user")).is_enabled( fc::log_level::debug ) ) \
       (fc::logger::get("user")).log( FC_LOG_MESSAGE( debug, FORMAT, __VA_ARGS__ ) ); \
-   } \
-  } while (0)
+  FC_MULTILINE_MACRO_END
 
 
 #define ilog( FORMAT, ... ) \
-  do { \
-   if( (fc::logger::get(DEFAULT_LOGGER)).is_enabled( fc::log_level::info ) ) { \
+  FC_MULTILINE_MACRO_BEGIN \
+   if( (fc::logger::get(DEFAULT_LOGGER)).is_enabled( fc::log_level::info ) ) \
       (fc::logger::get(DEFAULT_LOGGER)).log( FC_LOG_MESSAGE( info, FORMAT, __VA_ARGS__ ) ); \
-   } \
-  } while (0)
+  FC_MULTILINE_MACRO_END
 
 #define wlog( FORMAT, ... ) \
-  do { \
-   if( (fc::logger::get(DEFAULT_LOGGER)).is_enabled( fc::log_level::warn ) ) { \
+  FC_MULTILINE_MACRO_BEGIN \
+   if( (fc::logger::get(DEFAULT_LOGGER)).is_enabled( fc::log_level::warn ) ) \
       (fc::logger::get(DEFAULT_LOGGER)).log( FC_LOG_MESSAGE( warn, FORMAT, __VA_ARGS__ ) ); \
-   } \
-  } while (0)
+  FC_MULTILINE_MACRO_END
 
 #define elog( FORMAT, ... ) \
-  do { \
-   if( (fc::logger::get(DEFAULT_LOGGER)).is_enabled( fc::log_level::error ) ) { \
+  FC_MULTILINE_MACRO_BEGIN \
+   if( (fc::logger::get(DEFAULT_LOGGER)).is_enabled( fc::log_level::error ) ) \
       (fc::logger::get(DEFAULT_LOGGER)).log( FC_LOG_MESSAGE( error, FORMAT, __VA_ARGS__ ) ); \
-   } \
-  } while (0)
+  FC_MULTILINE_MACRO_END
 
 #include <boost/preprocessor/seq/for_each.hpp>
 #include <boost/preprocessor/seq/enum.hpp>
@@ -164,13 +167,13 @@ namespace fc
 // a slowdown.
 #ifdef FC_DISABLE_LOGGING
 # undef ulog
-# define ulog(...) do {} while(0)
+# define ulog(...) FC_MULTILINE_MACRO_BEGIN FC_MULTILINE_MACRO_END
 # undef elog
-# define elog(...) do {} while(0)
+# define elog(...) FC_MULTILINE_MACRO_BEGIN FC_MULTILINE_MACRO_END
 # undef wlog
-# define wlog(...) do {} while(0)
+# define wlog(...) FC_MULTILINE_MACRO_BEGIN FC_MULTILINE_MACRO_END
 # undef ilog
-# define ilog(...) do {} while(0)
+# define ilog(...) FC_MULTILINE_MACRO_BEGIN FC_MULTILINE_MACRO_END
 # undef dlog
-# define dlog(...) do {} while(0)
+# define dlog(...) FC_MULTILINE_MACRO_BEGIN FC_MULTILINE_MACRO_END
 #endif
\ No newline at end of file
diff --git a/src/crypto/base58.cpp b/src/crypto/base58.cpp
index 48fe27d..f7fc37e 100644
--- a/src/crypto/base58.cpp
+++ b/src/crypto/base58.cpp
@@ -618,7 +618,7 @@ std::string to_base58( const std::vector<char>& d )
 std::vector<char> from_base58( const std::string& base58_str ) {
    std::vector<unsigned char> out;
    if( !DecodeBase58( base58_str.c_str(), out ) ) {
-     FC_THROW_EXCEPTION( exception, "Unable to decode base58 string ${base58_str}", ("base58_str",base58_str) );
+     FC_THROW_EXCEPTION( parse_error_exception, "Unable to decode base58 string ${base58_str}", ("base58_str",base58_str) );
    }
    return std::vector<char>((const char*)out.data(), ((const char*)out.data())+out.size() );
 }
@@ -629,7 +629,7 @@ size_t from_base58( const std::string& base58_str, char* out_data, size_t out_da
   //slog( "%s", base58_str.c_str() );
   std::vector<unsigned char> out;
   if( !DecodeBase58( base58_str.c_str(), out ) ) {
-    FC_THROW_EXCEPTION( exception, "Unable to decode base58 string ${base58_str}", ("base58_str",base58_str) );
+    FC_THROW_EXCEPTION( parse_error_exception, "Unable to decode base58 string ${base58_str}", ("base58_str",base58_str) );
   }
   
   memcpy( out_data, out.data(), out.size() );
diff --git a/src/filesystem.cpp b/src/filesystem.cpp
index db33f1c..85dd1f5 100644
--- a/src/filesystem.cpp
+++ b/src/filesystem.cpp
@@ -19,6 +19,10 @@
   #include <sys/types.h>
   #include <sys/stat.h>
   #include <pwd.h>
+# ifdef FC_HAS_SIMPLE_FILE_LOCK  
+  #include <sys/file.h>
+  #include <fcntl.h>
+# endif
 #endif
 
 namespace fc {
@@ -495,4 +499,101 @@ namespace fc {
      return appCurrentPath;
    }
 
+
+#ifdef FC_HAS_SIMPLE_FILE_LOCK  
+  class simple_lock_file::impl
+  {
+  public:
+#ifdef _WIN32
+    HANDLE file_handle;
+#else
+    int file_handle;
+#endif
+    bool is_locked;
+    path lock_file_path;
+
+    impl(const path& lock_file_path);
+    ~impl();
+
+    bool try_lock();
+    void unlock();
+  };
+  
+  simple_lock_file::impl::impl(const path& lock_file_path) :
+    is_locked(false),
+    lock_file_path(lock_file_path),
+#ifdef _WIN32
+    file_handle(INVALID_HANDLE_VALUE)
+#else
+    file_handle(-1)
+#endif
+  {}
+   
+  simple_lock_file::impl::~impl()
+  {
+    unlock();
+  }
+
+  bool simple_lock_file::impl::try_lock()
+  {
+#ifdef _WIN32
+    HANDLE fh = CreateFileA(lock_file_path.to_native_ansi_path().c_str(),
+                            GENERIC_READ | GENERIC_WRITE,
+                            0, 0,
+                            OPEN_ALWAYS, 0, NULL);
+    if (fh == INVALID_HANDLE_VALUE)
+      return false;
+    is_locked = true;
+    file_handle = fh;
+    return true;
+#else
+    int fd = open(lock_file_path.string().c_str(), O_RDWR|O_CREAT, 0644);
+    if (fd < 0)
+      return false;
+    if (flock(fd, LOCK_EX|LOCK_NB) == -1)
+    {
+      close(fd);
+      return false;
+    }
+    is_locked = true;
+    file_handle = fd;
+    return true;
+#endif
+  }
+
+  void simple_lock_file::impl::unlock()
+  {
+#ifdef WIN32
+    CloseHandle(file_handle);
+    file_handle = INVALID_HANDLE_VALUE;
+    is_locked = false;
+#else
+    flock(file_handle, LOCK_UN);
+    close(file_handle);
+    file_handle = -1;
+    is_locked = false;
+#endif
+  }
+
+
+  simple_lock_file::simple_lock_file(const path& lock_file_path) :
+    my(new impl(lock_file_path))
+  {
+  }
+
+  simple_lock_file::~simple_lock_file()
+  {
+  }
+
+  bool simple_lock_file::try_lock()
+  {
+    return my->try_lock();
+  }
+
+  void simple_lock_file::unlock()
+  {
+    my->unlock();
+  }
+#endif // FC_HAS_SIMPLE_FILE_LOCK
+
 }
diff --git a/src/log/appender.cpp b/src/log/appender.cpp
index 737625c..c4d9c9e 100644
--- a/src/log/appender.cpp
+++ b/src/log/appender.cpp
@@ -7,6 +7,7 @@
 #include <fc/thread/scoped_lock.hpp>
 #include <fc/log/console_appender.hpp>
 #include <fc/log/file_appender.hpp>
+#include <fc/log/gelf_appender.hpp>
 #include <fc/variant.hpp>
 #include "console_defines.h"
 
@@ -45,4 +46,6 @@ namespace fc {
    
    static bool reg_console_appender = appender::register_appender<console_appender>( "console" );
    static bool reg_file_appender = appender::register_appender<file_appender>( "file" );
+   static bool reg_gelf_appender = appender::register_appender<gelf_appender>( "gelf" );
+
 } // namespace fc
diff --git a/src/log/gelf_appender.cpp b/src/log/gelf_appender.cpp
new file mode 100644
index 0000000..e8b7a7b
--- /dev/null
+++ b/src/log/gelf_appender.cpp
@@ -0,0 +1,139 @@
+#include <fc/network/udp_socket.hpp>
+#include <fc/network/ip.hpp>
+#include <fc/network/resolve.hpp>
+#include <fc/exception/exception.hpp>
+#include <fc/log/gelf_appender.hpp>
+#include <fc/reflect/variant.hpp>
+#include <fc/thread/scoped_lock.hpp>
+#include <fc/thread/thread.hpp>
+#include <fc/variant.hpp>
+#include <fc/io/json.hpp>
+
+#include <boost/thread/mutex.hpp>
+#include <boost/lexical_cast.hpp>
+#include <iomanip>
+#include <queue>
+#include <sstream>
+
+namespace fc 
+{
+
+  class gelf_appender::impl : public retainable
+  {
+  public:
+    config                     cfg;
+    optional<ip::endpoint>     gelf_endpoint;
+    udp_socket                 gelf_socket;
+    boost::mutex               socket_mutex;
+
+    impl(const config& c) : 
+      cfg(c)
+    {
+    }
+
+    ~impl()
+    {
+    }
+  };
+
+  gelf_appender::gelf_appender(const variant& args) :
+    my(new impl(args.as<config>()))
+  {
+    try
+    {
+      try
+      {
+        // if it's a numeric address:port, this will parse it
+        my->gelf_endpoint = ip::endpoint::from_string(my->cfg.endpoint);
+      }
+      catch (...)
+      {
+      }
+      if (!my->gelf_endpoint)
+      {
+        // couldn't parse as a numeric ip address, try resolving as a DNS name.  
+        // This can yield, so don't do it in the catch block above
+        string::size_type colon_pos = my->cfg.endpoint.find(':');
+        try
+        {
+          uint16_t port = boost::lexical_cast<uint16_t>(my->cfg.endpoint.substr(colon_pos + 1, my->cfg.endpoint.size()));
+
+          string hostname = my->cfg.endpoint.substr( 0, colon_pos );
+          std::vector<ip::endpoint> endpoints = resolve(hostname, port);
+          if (endpoints.empty())
+              FC_THROW_EXCEPTION(unknown_host_exception, "The host name can not be resolved: ${hostname}", 
+                                 ("hostname", hostname));
+          my->gelf_endpoint = endpoints.back();
+        }
+        catch (const boost::bad_lexical_cast&)
+        {
+          FC_THROW("Bad port: ${port}", ("port", my->cfg.endpoint.substr(colon_pos + 1, my->cfg.endpoint.size())));
+        }
+      }
+
+      if (my->gelf_endpoint)
+        my->gelf_socket.open();
+    }
+    catch (...)
+    {
+      std::cerr << "error opening GELF socket to endpoint ${endpoint}" << my->cfg.endpoint << "\n";
+    }
+  }
+
+  gelf_appender::~gelf_appender()
+  {}
+
+  void gelf_appender::log(const log_message& message)
+  {
+    if (!my->gelf_endpoint)
+      return;
+
+    log_context context = message.get_context();
+
+    mutable_variant_object gelf_message;
+    gelf_message["version"] = "1.1";
+    gelf_message["host"] = my->cfg.host;
+    gelf_message["short_message"] = format_string(message.get_format(), message.get_data());
+    
+    gelf_message["timestamp"] = context.get_timestamp().time_since_epoch().count() / 1000000.;
+
+    switch (context.get_log_level())
+    {
+    case log_level::debug:
+      gelf_message["level"] = 7; // debug
+      break;
+    case log_level::info:
+      gelf_message["level"] = 6; // info
+      break;
+    case log_level::warn:
+      gelf_message["level"] = 4; // warning
+      break;
+    case log_level::error:
+      gelf_message["level"] = 3; // error
+      break;
+    case log_level::all:
+    case log_level::off:
+      // these shouldn't be used in log messages, but do something deterministic just in case
+      gelf_message["level"] = 6; // info
+      break;
+    }
+
+    if (!context.get_context().empty())
+      gelf_message["context"] = context.get_context();
+    gelf_message["_line"] = context.get_line_number();
+    gelf_message["_file"] = context.get_file();
+    gelf_message["_method_name"] = context.get_method();
+    gelf_message["_thread_name"] = context.get_thread_name();
+    if (!context.get_task_name().empty())
+      gelf_message["_task_name"] = context.get_task_name();
+
+    string gelf_message_as_string = json::to_string(gelf_message);
+    std::shared_ptr<char> send_buffer(new char[gelf_message_as_string.size()], [](char* p){ delete[] p; });
+    memcpy(send_buffer.get(), gelf_message_as_string.c_str(), gelf_message_as_string.size());
+
+    {
+      scoped_lock<boost::mutex> lock(my->socket_mutex);
+      my->gelf_socket.send_to(send_buffer, gelf_message_as_string.size(), *my->gelf_endpoint);
+    }
+  }
+} // fc
diff --git a/src/log/log_message.cpp b/src/log/log_message.cpp
index 7e26cf4..09b6815 100644
--- a/src/log/log_message.cpp
+++ b/src/log/log_message.cpp
@@ -83,7 +83,9 @@ namespace fc
 
    void log_context::append_context( const fc::string& s )
    {
-        my->context += "->" + s;
+        if (!my->context.empty())
+          my->context += " -> ";
+        my->context += s;
    }
 
    log_context::~log_context(){}
@@ -158,6 +160,7 @@ namespace fc
    string     log_context::get_host_name()const   { return my->hostname; }
    time_point  log_context::get_timestamp()const  { return my->timestamp; }
    log_level  log_context::get_log_level()const{ return my->level;   }
+   string     log_context::get_context()const   { return my->context; }
 
 
    variant log_context::to_variant()const
diff --git a/src/network/http/http_server.cpp b/src/network/http/http_server.cpp
index e0dd9b6..648fc54 100644
--- a/src/network/http/http_server.cpp
+++ b/src/network/http/http_server.cpp
@@ -25,7 +25,7 @@ namespace fc { namespace http {
             case fc::http::reply::RecordCreated: ss << "Record Created\r\n"; break;
             case fc::http::reply::NotFound: ss << "Not Found\r\n"; break;
             case fc::http::reply::Found: ss << "Found\r\n"; break;
-            case fc::http::reply::InternalServerError: ss << "Internal Server Error\r\n"; break;
+            default: ss << "Internal Server Error\r\n"; break;
          }
          for( uint32_t i = 0; i < rep.headers.size(); ++i ) {
             ss << rep.headers[i].key <<": "<<rep.headers[i].val <<"\r\n";
diff --git a/src/rpc/json_connection.cpp b/src/rpc/json_connection.cpp
index 327a3ca..82cd566 100644
--- a/src/rpc/json_connection.cpp
+++ b/src/rpc/json_connection.cpp
@@ -43,8 +43,8 @@ namespace fc { namespace rpc {
                  *_out << ",\"result\":";
                  json::to_stream( *_out, result);
                  *_out << "}\n";
+                 _out->flush();
                }
-               _out->flush();
             }
             void send_error( variant id, fc::exception& e )
             {
@@ -59,9 +59,9 @@ namespace fc { namespace rpc {
                  *_out <<",\"code\":0,\"data\":";
                  json::to_stream( *_out, variant(e));
                  *_out << "}}\n";
+                 _out->flush();
                }
                //wlog(  "exception: ${except}", ("except", variant(e)) );
-               _out->flush();
             }
 
             void handle_message( const variant_object& obj )
@@ -306,8 +306,8 @@ namespace fc { namespace rpc {
         *my->_out << ",\"params\":";
         fc::json::to_stream( *my->_out, named_args );
         *my->_out << "}\n";
+        my->_out->flush();
       }
-      my->_out->flush();
    }
    void json_connection::notice( const fc::string& method )
    {
@@ -316,8 +316,8 @@ namespace fc { namespace rpc {
         *my->_out << "{\"method\":";
         json::to_stream( *my->_out, method );
         *my->_out << "}\n";
+        my->_out->flush();
       }
-      my->_out->flush();
    }
 
 
@@ -342,8 +342,8 @@ namespace fc { namespace rpc {
          {
             *my->_out << ",\"params\":[]}\n";
          }
+         my->_out->flush();
       }
-      my->_out->flush();
       return my->_awaiting[id];
    }
 
@@ -361,8 +361,8 @@ namespace fc { namespace rpc {
          *my->_out << ",\"params\":[";
          fc::json::to_stream( *my->_out, a1 );
          *my->_out << "]}\n";
+         my->_out->flush();
       }
-      my->_out->flush();
       return my->_awaiting[id];
    }
    future<variant> json_connection::async_call( const fc::string& method, const variant& a1, const variant& a2 )
@@ -381,8 +381,8 @@ namespace fc { namespace rpc {
          *my->_out << ",";
          fc::json::to_stream( *my->_out, a2 );
          *my->_out << "]}\n";
+         my->_out->flush();
       }
-      my->_out->flush();
       return my->_awaiting[id];
    }
    future<variant> json_connection::async_call( const fc::string& method, const variant& a1, const variant& a2, const variant& a3 )
@@ -403,8 +403,8 @@ namespace fc { namespace rpc {
          *my->_out << ",";
          fc::json::to_stream( *my->_out, a3 );
          *my->_out << "]}\n";
+         my->_out->flush();
       }
-      my->_out->flush();
       return my->_awaiting[id];
    }
 
@@ -428,8 +428,8 @@ namespace fc { namespace rpc {
          *my->_out << ",";
          fc::json::to_stream( *my->_out, a4 );
          *my->_out << "]}\n";
+         my->_out->flush();
       }
-      my->_out->flush();
       return my->_awaiting[id];
    }
 
@@ -455,8 +455,8 @@ namespace fc { namespace rpc {
          *my->_out << ",";
          fc::json::to_stream( *my->_out, a5 );
          *my->_out << "]}\n";
+         my->_out->flush();
       }
-      my->_out->flush();
       return my->_awaiting[id];
    }
 
@@ -484,8 +484,8 @@ namespace fc { namespace rpc {
          *my->_out << ",";
          fc::json::to_stream( *my->_out, a6 );
          *my->_out << "]}\n";
+         my->_out->flush();
       }
-      my->_out->flush();
       return my->_awaiting[id];
    }
    future<variant> json_connection::async_call( const fc::string& method, const variant& a1, const variant& a2, const variant& a3, const variant& a4, const variant& a5, const variant& a6, const variant& a7 )
@@ -514,8 +514,8 @@ namespace fc { namespace rpc {
          *my->_out << ",";
          fc::json::to_stream( *my->_out, a7 );
          *my->_out << "]}\n";
+         my->_out->flush();
       }
-      my->_out->flush();
       return my->_awaiting[id];
    }
    future<variant> json_connection::async_call( const fc::string& method, 
@@ -554,8 +554,8 @@ namespace fc { namespace rpc {
          *my->_out << ",";
          fc::json::to_stream( *my->_out, a8 );
          *my->_out << "]}\n";
+         my->_out->flush();
       }
-      my->_out->flush();
       return my->_awaiting[id];
    }
    future<variant> json_connection::async_call( const fc::string& method, 
@@ -597,8 +597,8 @@ namespace fc { namespace rpc {
          *my->_out << ",";
          fc::json::to_stream( *my->_out, a9 );
          *my->_out << "]}\n";
+         my->_out->flush();
       }
-      my->_out->flush();
       return my->_awaiting[id];
    }
    future<variant> json_connection::async_call( const fc::string& method, 
@@ -643,8 +643,8 @@ namespace fc { namespace rpc {
          *my->_out << ",";
          fc::json::to_stream( *my->_out, a10 );
          *my->_out << "]}\n";
+         my->_out->flush();
       }
-      my->_out->flush();
       return my->_awaiting[id];
    }
 
@@ -665,8 +665,8 @@ namespace fc { namespace rpc {
          *my->_out << ",\"params\":";
          fc::json::to_stream( *my->_out, named_args );
          *my->_out << "}\n";
+         my->_out->flush();
       }
-      my->_out->flush();
       return my->_awaiting[id];
    }
    future<variant> json_connection::async_call( const fc::string& method )
@@ -680,8 +680,8 @@ namespace fc { namespace rpc {
         *my->_out << ",\"method\":";
          json::to_stream( *my->_out, method );
         *my->_out << "}\n";
+         my->_out->flush();
       }
-      my->_out->flush();
       return my->_awaiting[id];
    }