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Re: Slow Application Startup



On Tue, Aug 17, 2004 at 01:48:12PM -0400, Thom Paine wrote:
> On Tue, 2004-08-17 at 13:34, Norm Deane wrote:
> > I recently upgraded my RH9 (Dell Inspiron 8200/) to
> > FC2.  The upgrade went well but after upgrading I've
> > noticed that applications take forever (some take 5+
> > minutes) to start.  Once they are running they perform
> > ok.
> > 
> 
> Which applications are taking a while to load?

Yes what application...

In my experience you are having trouble resolving a host name or other
network thing (perhaps some IPv6 thing).  Internet timeouts can be
many seconds long.

To be sure, we should not guess when we do not have to.  It is
possible to run most applications with "strace" and see what takes so
long.

Something like this command line:

	  strace -f -r -o/tmp/trace-xterm xterm

Most things that take more than 0.00nnn would be interesting.
(except waiting for your keyboard I/O).  Note Well (N.B.) that
we only see the system calls, not the library and other function
calls.  But since disk and network IO are the most common 
bottlenecks we should look for network and disk IO (read()
and for select() we might use -t or -tt to time stamp things.

You might quickly check/ time hostname lookup to test my assertion
thus...

    $ time host localhost
    localhost has address 127.0.0.1

    real    0m0.161s
    user    0m0.003s
    sys     0m0.008s

    $ time host thisbox.com
    thisbox.com has address 192.169.0.55

    real    0m0.028s
    user    0m0.001s
    sys     0m0.006s


It can  be interesting to see what else is going on.

   $ top -n1 

   Remember that there are numerous house keeping tasks that 
   might be run if the box has been off for some time.  Some
   of these do lots of I/O once in a while....


-- 
	T o m  M i t c h e l l 
	Just say no to 74LS73 in 2004



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