delay in response to "w" comand

[swortsoul]

This has been bugging me for a while. Whenever a user is idle for a while (not sure how long, this time over an hour), the response to the "w" command is very slow. If I kill their session, it runs fast like normal. Anyone know why this is? Here's an example:

I added the line numbers to help explain.

1: # w
2: 04:17PM up 50 days, 23:58, 5 users, load average: 0.23, 0.58, 0.77
3: User tty login@ idle JCPU PCPU what
4: user1 pts/0 12:51PM 2:20 0 0 -ksh
5: user1 pts/1 01:58PM 2:19 0 0 -ksh
6: user2 pts/3 02:20PM 1:56 2 0 -ksh
7: user3 pts/5 12:07PM 0 0 0 -ksh
8: user4 pts/7 03:42PM 0 0 0 -ksh

So, in this case, lines 1-3 show up quick, then there is a few second pause before line4, pause before line5, pause before line6, then the last 2 lines show very quick.

Any ideas?

Thanks
Tim

 

[swortsoul]

Anyone have any ideas?

Thanks
Tim

 

[RodKnowlton]

No idea why it would do that, but you can test your hypothesis further.

Login a session of you own, and leave it idle for a couple of hours. Then, while leaving that session idle, check "w" from another terminal/session. If it slows at your first session's line, switch to that session and do any old thing to take it out of idle status. Then check "w" to see if it no longer pauses on your first session.

Okay, here's one idea, although I wouldn't call it a good one. Is your machine cpu bound by a server (at least a non-login) process? The "w" lines with idle logons would require a (very small) calculation. If you were cpu bound enough, that might show up as a perceptible delay.







Rod Knowlton
IBM Certified Advanced Technical Expert pSeries and AIX 5L

 

[swortsoul]

Thanks, I will try that. Something else I just noticed. It only slows down if I have su'd to root. When I do a "w" from my normal user, it responds quickly. Also, the users with the idle sessions are coming in from a PC using Exceed. They don't think they have open sessions any longer. I don't know how they are logging off, but they don't have an xterm open anymore.

I don't believe we are cpu bound, but I will check that.

Thanks
Tim

 

[ogniemi]

I had a similiar problem. On my site I solved it as follows>
(users are also using exceed)

1. determined account which causes the problem (w hangs on that user)
2. went to ~the_user/.dt/sessions/current and deleted all current and current.old files

When user reloged the problem dissappeared.


r, m.