How much time is required for creating a new process in apache web server

Question

In my application, we are using Apache 2.4 Windows Server.

Below is my winnt configuration

<IfModule mpm_winnt_module> ThreadsPerChild 1900 MaxConnectionsPerChild 8000 </IfModule> 

According to the above configuration, a new process is created in server for every 8000 requests.

In my application every day 500000 transactions are coming. What value in MaxConnectionsPerChild gives the good performance.

Below is my questions:

1. How much time its required for creating a New Process? 2. While creating the new process, If any requests comes to web server will it accept or not? 3. If the request hit reached 8000, will it drop all the current processing request or the request will move to new process. 4. If the request hit reached 8000, If any requests comes to web server will it accept or not? 5. Winnt module have only one process, so its good or bad to keep non zero values in MaxConnectionsPerChild ? 

I didn't have the reference in internet to finding the answer for above question. Can someone please help me to get clarified on above things?

Any help will be greatly appreciated!!!

Answer 1

The short answer:

• as winnt MPM only uses one process to spawn threads, consider using the ThreadsPerChild directive.
• For your server leave the MaxConnectionsPerChild directive set to 0 (the default): there is no connection limit so the thread spawning process will not die.

More info from Apache documentation for winnt MPM.

ThreadsPerChild directive-:

This directive sets the number of threads created by each child process. The child creates these threads at startup and never creates more. If using an MPM like mpm_winnt, where there is only one child process, this number should be high enough to handle the entire load of the server at peak time, allowing for some contingency in case of exceptional demand.

1. How much time its required for creating a New Process?

Depends, e.g. what processes are scheduled, what interrupts may occur, what system resources are available to manage processes. Windows process creation is expensive though.

2. While creating the new process, If any requests comes to web server will it accept or not?

It will not accept. The child process when starting creates the threads used to process requests.

3. If the request hit reached 8000, will it drop all the current processing request or the request will move to new process?

Neither: requests do not get moved to a new process, and there is a grace period of TimeOut seconds before active requests are terminated.

4. If the request hit reached 8000, If any requests comes to web server will it accept or not?

If will not accept requests until the child process starts all it's worker threads.

5. Winnt module have only one process, so its good or bad to keep non zero values?

Based on the load your server encounters keep the MaxConnectionsPerChild directive set to 0 (the default).

The MaxConnectionsPerChild directive sets the limit on the number of connections that an individual child server process will handle. After MaxConnectionsPerChild connections, the child process will die. If MaxConnectionsPerChild is 0, then the process will never expire.