What is the difference between a daemon and a server process?

Asked by Pari Kulkarni

Q.What is the difference between a daemon and a server process?

A. A 'daemon' is a software process that runs in the background (continuously) and provides the service to client upon request. For example named is a daemon. When requested it will provide DNS service. Other examples are:

  • xinetd (it is a super-daemon, it is responsible for invoking other Internet servers when they are needed)
  • inetd (same as xinetd, but with limited configuration options)
  • sendmail/postfix (to send/route email)
  • Apache/httpd (web server)

Following simple example illustrate relationship between client and daemon.

CLIENT  -> Daemon

Browser Running one daemon for each of the services could significantly increase the load. However if you are running big site (with many user) it is advisable to use dedicated daemon. For example web server or MySQL database server.

A 'server process' run runs one time, when called by a daemon. Once done it will stop. For example telnetd (in.telnetd) or ftpd called from xinetd/inetd daemon . By calling server process from daemon you can save the load and memory. Use a server process for small services such as ftpd, telnetd

CLIENT -> Daemon   -> Calls server process
ftp    -> xinetd   -> Calls ftpd
ftp     xinetd stops ftpd
quit
Want to read Linux tips and tricks, but don't have time to check our blog everyday? Subscribe to our daily email newsletter to make sure you don't miss a single tip/tricks. Subscribe to our weekly newsletter here!

{ 1 comment… read it below or add one }

1 adinarayana 12.24.07 at 5:02 pm

it is good

if i want to restart a service can i directly restart the service

or i want to restart pariticular daemon

what is difference

can u clear this

thanks in advance.

Leave a Comment

You can use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>

Previous post: Use Crontab Command With sys account

Next post: What is Maximum Partition size supported by Linux?