SUMMARY: Many processes remain until reboot

From: Matthew SAMS (maclean@mnementh.cs.mcgill.ca)
Date: Sat May 14 1994 - 14:22:13 CDT


I apologize for the 6 week delay in the summary.

Thanks to the following people who responded and gave advice:
carl@oversteer.library.uwa.edu.au (Carl Brewer)
"DISCO::EDM"@MOG.WR.USGS.GOV (Ed Maple, U.S. Geological Survey)
almaline@aol.com
wallen@cogsci.UCSD.EDU (Mark R. Wallen)

We came to the conclusion that there was a bug in Solbourne's
OS/MP4.1B (Sunos 4.1.2). We upgraded to 4.1C(Sunos 4.1.3) but
the problem persisted. After much discussion with Solbourne
technical support we determined the following.

If a telnet/rlogin session is terminated abnormally any processes
which were running are not terminated. The machine must be rebooted
in order to remove all of these processes.
An abnormal termination would be caused by disconnecting the modem,
killing the telnet/rlogin process, or destroying the window from which
you are working.

This was a bug reported in OS/MP 4.1B and reportedly fixed in 4.1C.
Obviously it wasn't and is being reexamined.

The original article is included below. Note that the network
connections also came from other unix boxes, not just terminal
servers as I stated.

Thank you
Matthew

-----------------------------------------------------------------------------
Matthew Sams School of Computer Science
Systems Programmer McGill University
maclean@cs.mcgill.ca Montreal, QC
514 398 5320 fax 514 398 3883
-----------------------------------------------------------------------------

>
>Solbourne 5/602 machine with 2 Series 5 sparc cpu boards and 192M ram
>running Sun os 4.1.2. We are using it as a compute server for ~80
>simultaneous users. All connections are through the network from a
>Xylogics Annex IIe terminal server.
>
>Problem:
>
>Processes are left in the process table and holding on to a pty after
>a user leaves. We are unsure if this happens every time a user logs out
>or only when the connection is broken. Eventually we run out of ptys.
>'w' claims that few users are on and /dev/tty* are mostly owned by
>root except for those users actually logged in. There are 96 ptys in
>the kernel and /dev. The number of users on is usually less than 30.
>
>Some processes will disappear if you attach trace to the process.
>Other processes need a kill -9. Any process can be left in the table from
>'sh' to 'telnet'. All are in a sleep state.
>
>Changes:
... irrelevant changes to kernel config files deleted..



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