Thanks Alan for the reply

I have done changes to traffic manager source to support two instances of traffic server to run in the system. 
Now I can see two different set of .../var/ files are created the moment I run traffic_manager. It includes three .sock files too. 
I was trying to find out where exactly the IPC call happens from traffic_control. Could you please help me understand the call sequence from traffoc_control on how this IPC works - like which library function is doing this work ? I assume that it is just delivering some message from traffic_ctl to traffic_manager ( ? )


On 28 March 2017 at 20:34, Alan Carroll <> wrote:
traffic_ctl does IPC over a UNIX pipe to communicate with traffic_manager which will, if needed, communicate with traffic_server. The file name of the pipe is a compile time constant in traffic_ctl and traffic_manager. Therefore which Traffic Server instance is affected is based on which traffic_ctl binary you use.

On Monday, March 27, 2017, 8:12:56 PM CDT, salil GK <> wrote:


  I have a doubt regarding the traffic_ctl command. In my setup I am running two instances of traffic server. This I am doing by specifying two different directories for configuration. Now when I run traffic_ctl  how do I control the configuration reload. I mean traffic_ctl need to read the correct configuration file and update the variables of respective instance. How do I do this ?

How does the trfficctl update the configuration variables of traffic_server – is it some IPC mechanism ?