Date: Sun, 4 Mar 2001 00:07:15 +0900 From: "=?euc-kr?B?sejA57/s?=" <h881108@kornet.net> To: <freebsd-questions@FreeBSD.ORG> Subject: Ghost process with broken telnet connection. Message-ID: <000701c0a3f3$a28e7780$6606a8c0@kyeungja.dbsoft.co.kr>
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[-- Attachment #1 --]
I have 2 FreeBSD 4.2 system, one for telnet service and
the orther for application development.
I have find out some strange things concernning with
telnet connections, especially in broken telnet connections.
Hereinafter, my experiences;
AA. Tested Software
FreeBSD 4.2 Release
FreeBSD 4 Stable 2001.02.18 snap.kr.install.iso
FreeBSD 4.11 Release
BB. Tested Telnet Client
NetTerm 4.2
Telnet.exe included in Win98
telnet included in FreeBSD and Linux
CC. Tested Hardware
Intel Server 800MHz with 256MB RAM, 8GB Segate SCSI HDD, 100MBPS Intel NIC
Pentium 150MHz with 64MB RAM, 30GB IBM HDD, 10MBPS 3C900 NIC
DD. Procedures
aa. Open two telnet clients window at Win98 or orther clients
bb. Run infinite loop program ( ex. top ) at each telnet terminal after successfully login to BSD.
cc. Disconnect one telnet client connection without normal procedure.
This means break the telnet connection in force, killing telnet client window is a example.
dd. Then watch the orther telnet client's window, the top process says the idle CPU time is almost zero(0) per cent.
And you will find out the infinite loop process( another top which ran from broken telnet session in this case )
remains and occupy every CPU time.
My guess is the process belongs to broken telnet session does not realize that session was broken and
retry to create a new process tediously, but nothing is clear.
ee. A shell script which read user input from keyboard in a loop makes same result.
ff. After a couple of test, system's reply is slow down in significant.
Especially lots of I/O, ls -lRa /* in example.
One day my telnet server had 450 more processes without any logged in user, most of them are
the ghost process described above.
Is there anyone who knows solutions or suggestions for this problem, who experienced same thing ?
Thanks
h881108@kornet.net KIM Jaewoo
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<DIV><FONT size=2>I have 2 FreeBSD 4.2 system, one for telnet service and
</FONT></DIV>
<DIV><FONT size=2>the orther for application development.</FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2>I have find out some strange things concernning with
</FONT></DIV>
<DIV><FONT size=2>telnet connections, especially in broken telnet
connections.</FONT></DIV>
<DIV><FONT size=2>Hereinafter, my experiences;</FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2>AA. Tested Software</FONT></DIV>
<DIV><FONT size=2> FreeBSD 4.2
Release</FONT></DIV>
<DIV><FONT size=2> FreeBSD 4 Stable
2001.02.18 snap.kr.install.iso</FONT></DIV>
<DIV><FONT size=2> FreeBSD 4.11
Release</FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2>BB. Tested Telnet Client</FONT></DIV>
<DIV><FONT size=2> NetTerm 4.2</FONT></DIV>
<DIV><FONT size=2></FONT><FONT color=#000000
size=2> Telnet.exe included in
Win98</FONT></DIV>
<DIV><FONT color=#000000 size=2></FONT><FONT
size=2> telnet included in FreeBSD and
Linux</FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2>CC. Tested Hardware</FONT></DIV>
<DIV><FONT size=2> Intel Server 800MHz with
256MB RAM, 8GB Segate SCSI HDD, 100MBPS Intel NIC</FONT></DIV>
<DIV><FONT size=2> Pentium 150MHz with 64MB
RAM, 30GB IBM HDD, 10MBPS 3C900 NIC</FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2>DD. Procedures</FONT></DIV>
<DIV><FONT size=2> </FONT></DIV>
<DIV><FONT size=2> aa. Open two telnet
clients window at Win98 or orther clients</FONT></DIV>
<DIV><FONT size=2> bb. Run infinite loop
program ( ex. top ) at each telnet terminal after successfully login to
BSD.</FONT></DIV>
<DIV><FONT size=2> cc. Disconnect one telnet
client connection without normal procedure.</FONT></DIV>
<DIV><FONT
size=2>
This means break the telnet connection in force, killing telnet client window is
a example.</FONT></DIV>
<DIV><FONT size=2> dd. Then watch the orther
telnet client's window, the top process says the idle CPU time is almost zero(0)
per cent.</FONT></DIV>
<DIV><FONT
size=2>
And you will find out the infinite loop process( another top which ran from
broken telnet session in this case ) </FONT></DIV>
<DIV><FONT
size=2>
remains and occupy every CPU time.</FONT></DIV>
<DIV><FONT
size=2>
My guess is the process belongs to broken telnet session does not realize that
session was broken and</FONT></DIV>
<DIV><FONT
size=2>
retry to create a new process tediously, but nothing is clear.</FONT></DIV>
<DIV><FONT size=2> ee. A shell script which
read user input from keyboard in a loop makes same result.</FONT></DIV>
<DIV><FONT size=2> ff. After a
couple of test, system's reply is slow down in significant.</FONT></DIV>
<DIV><FONT
size=2>
Especially lots of I/O, ls -lRa /* in example.</FONT></DIV>
<DIV><FONT size=2></FONT><FONT color=#000000
size=2>
One day my telnet server had 450 more processes without any logged in user, most
of them are </FONT></DIV>
<DIV><FONT color=#000000 size=2></FONT><FONT
size=2>
the ghost process described above.</FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2>Is there anyone who knows solutions or suggestions for this
problem, who </FONT><FONT size=2>experienced same thing ?</FONT></DIV>
<DIV><FONT size=2></FONT><FONT color=#000000 size=2>Thanks </FONT></DIV>
<DIV><FONT color=#000000 size=2></FONT> </DIV>
<DIV><FONT size=2><A href="mailto:h881108@kornet.net">h881108@kornet.net</A> KIM
Jaewoo</FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV> </DIV>
<DIV><FONT
size=2> </FONT></DIV>
<DIV><FONT size=2> </FONT></DIV>
<DIV><FONT
size=2> </FONT></DIV></BODY></HTML>
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