diff --git a/examples/nginx.conf b/examples/nginx.conf
index 00522bb..77b7eac 100644
--- a/examples/nginx.conf
+++ b/examples/nginx.conf
@@ -36,7 +36,7 @@
         local metadata_buffer = ngx.shared.metadata_buffer
         metadata_buffer['serviceName'] = 'Service Name'
 
-        require("tracing"):startTimer(metadata_buffer, "http://127.0.0.1:8080/skywalking")
+        require("client"):startTimer(metadata_buffer, "http://127.0.0.1:8080/skywalking")
     }
 
     server {
diff --git a/lib/skywalking/tracing.lua b/lib/skywalking/client.lua
similarity index 86%
rename from lib/skywalking/tracing.lua
rename to lib/skywalking/client.lua
index bc98370..48bba96 100644
--- a/lib/skywalking/tracing.lua
+++ b/lib/skywalking/client.lua
@@ -15,11 +15,11 @@
 -- limitations under the License.
 -- 
 
-local Tracing = {}
+local Client = {}
 
 -- Tracing timer does the service and instance register
 -- After register successfully, it sends traces and heart beat
-function Tracing:startTimer(metadata_buffer, backend_http_uri)
+function Client:startTimer(metadata_buffer, backend_http_uri)
     -- The codes of timer setup is following the OpenResty timer doc
     local delay = 3  -- in seconds
     local new_timer = ngx.timer.at
@@ -34,6 +34,13 @@
                 self:registerService(metadata_buffer, backend_http_uri)
             end
 
+            -- Register is in the async way, if register successfully, go for instance register
+            if metadata_buffer['serviceId'] ~= nil then
+                if metadata_buffer['serviceInstId'] == nil then
+                    
+                end
+            end
+
             -- do the health check
             local ok, err = new_timer(delay, check)
             if not ok then
@@ -53,7 +60,7 @@
 end
 
 -- Register service
-function Tracing:registerService(metadata_buffer, backend_http_uri)
+function Client:registerService(metadata_buffer, backend_http_uri)
     local log = ngx.log
     local DEBUG = ngx.DEBUG
 
@@ -86,4 +93,4 @@
     end
 end
 
-return Tracing
\ No newline at end of file
+return Client
\ No newline at end of file