wait for service:Service [/gazebo/set_physics_properties] has not been advertised, waiting...

edit

When I am trying to launch the my_world.launch I am facing this problem.

Code for my_world.launch is

<?xml version="1.0" encoding="UTF-8"?>

<launch>
 <arg name="debug" default="false" />
 <arg name="gui" default="false" />
 <arg name="pause" default="true" />
 <arg name="world" default="$(find my_gazebo)/world/empty_world.world" />
 <include file = "$(find gazebo_ros)/launch/empty_world.launch">
  <arg name="world_name" value="$(arg world)" />
  <arg name="debug" value="$(arg debug)" />
  <arg name="gui" value="$(arg gui)" />
  <arg name="paused" value="$(arg pause)" />
  <arg name="use_sim_time" value="true" />

 </include>

</launch>

empty_world.world code is here:

 <?xml version="1.0" ?>
    <sdf version="1.6">
      <world name="default">
       <include>
         <uri>model://sun</uri>
       </include>
       <include>
         <uri>model://ground_plane</uri>
       </include>
      </world>
    </sdf>

I am facing this problem:

glv@VaraPrasad:~/catkin_ws$ roslaunch my_gazebo my_world.launch
... logging to /home/glv/.ros/log/09788d08-d7b3-11e8-a35c-9822ef7fc42b/roslaunch-VaraPrasad-4041.log
Checking log directory for disk usage. This may take awhile.
Press Ctrl-C to interrupt
Done checking log file disk usage. Usage is <1GB.

started roslaunch server http://VaraPrasad:44853/

SUMMARY
========

PARAMETERS
 * /rosdistro: kinetic
 * /rosversion: 1.12.14
 * /use_sim_time: True

NODES
  /
    gazebo (gazebo_ros/gzserver)

ROS_MASTER_URI=http://localhost:11311

process[gazebo-1]: started with pid [4058]
[ INFO] [1540402702.643569843]: Finished loading Gazebo ROS API Plugin.
[ INFO] [1540402702.644173326]: waitForService: Service [/gazebo/set_physics_properties] has not been advertised, waiting...
[ INFO] [1540402702.908795885, 0.024000000]: waitForService: Service [/gazebo/set_physics_properties] is now available.
[ INFO] [1540402702.963873717, 0.078000000]: Physics dynamic reconfigure ready.
^C[gazebo-1] killing on exit
shutting down processing monitor...
... shutting down processing monitor complete
done
glv@VaraPrasad:~/catkin_ws$ 
glv@VaraPrasad:~/catkin_ws$ roslaunch my_gazebo my_world.launch
... logging to /home/glv/.ros/log/09788d08-d7b3-11e8-a35c-9822ef7fc42b/roslaunch-VaraPrasad-4309.log
Checking log directory for disk usage. This may take awhile.

Press Ctrl-C to interrupt
Done checking log file disk usage. Usage is <1GB.

started roslaunch server http://VaraPrasad:37831/

SUMMARY
========

PARAMETERS
 * /rosdistro: kinetic
 * /rosversion: 1.12.14
 * /use_sim_time: True

NODES
  /
    gazebo (gazebo_ros/gzserver)

ROS_MASTER_URI=http://localhost:11311

process[gazebo-1]: started with pid [4326]
[ INFO] [1540402736.589018029]: Finished loading Gazebo ROS API Plugin.
[ INFO] [1540402736.589433988]: waitForService: Service [/gazebo/set_physics_properties] has not been advertised, waiting...

I am using Ros Kinetic version , Ubuntu 16.04 and Gazebo 9

Thanks In Advance.