fix: shuffling array of contact points

Also provide the port number in socket error logs.

src/cassandra/protocol/reader_v2.lua

@@ -26,12 +26,12 @@ function _M:receive_frame(session)
 
   local header, err = session.socket:receive(8)
   if not header then
-    return nil, string.format("Failed to read frame header from %s: %s", session.host, err)
+    return nil, string.format("Failed to read frame header from %s:%s : %s", session.host, session.port, err)
   end
   local header_buffer = unmarshaller:create_buffer(header)
   local version = unmarshaller:read_raw_byte(header_buffer)
   if version ~= self.constants.version_codes.RESPONSE then
-    return nil, string.format("Invalid response version received from %s", session.host)
+    return nil, string.format("Invalid response version received from %s:%s", session.host, session.port)
   end
   local flags = unmarshaller:read_raw_byte(header_buffer)
   local stream = unmarshaller:read_raw_byte(header_buffer)
@@ -42,7 +42,7 @@ function _M:receive_frame(session)
   if length > 0 then
     body, err = session.socket:receive(length)
     if not body then
-      return nil, string.format("Failed to read frame body from %s: %s", session.host, err)
+      return nil, string.format("Failed to read frame body from %s:%s : %s", session.host, session.port, err)
     end
   else
     body = ""

src/cassandra/session.lua

@@ -20,7 +20,7 @@ function _M:send_frame_and_get_response(op_code, frame_body, tracing)
   local frame = self.writer:build_frame(op_code, frame_body, tracing)
   bytes, err = self.socket:send(frame)
   if not bytes then
-    return nil, cerror(string.format("Failed to send frame to %s: %s", self.host, err))
+    return nil, cerror(string.format("Failed to send frame to %s: %s:%s", self.host, self.port, err))
   end
   response, err = self.reader:receive_frame(self)
   if not response then

src/cassandra/utils.lua

@@ -15,6 +15,8 @@ function _M.big_endian_representation(num, bytes)
   return padding .. table.concat(t)
 end
 
+math.randomseed(os.time())
+
 -- @see http://en.wikipedia.org/wiki/Fisher-Yates_shuffle
 function _M.shuffle_array(arr)
   local n = #arr