Hi,

I'm using lftp 3.5.1 on Red Hat Enterprise Linux 5 and I'm seeing a
problem where lftp hangs in a loop using 100% of the CPU and no
further file transfers take place.

-------

$ lftp --version
LFTP | Version 3.5.1 | Copyright (c) 1996-2006 Alexander V. Lukyanov

LFTP is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.
There is absolutely no warranty for LFTP.  See COPYING for details.

Send bug reports and questions to <[email protected]>.

Libraries used: Readline 5.1

--------

I'm creating a script and then running "lftp -f script" from a perl
hack.  The script starts with the following:

set cmd:verbose yes
set net:timeout 300
set net:max-retries 5
set cmd:fail-exit true
set cmd:move-background false

And then opens a passworded connection to an sftp server after which
it uses multiple "pget"s to download a big steaming pile of large
files.

The perl hack is reading from the stdout of the lftp process and the
stderr of the lftp process is dup'ed to stderr:

lftp -f script 2>&1

After some number of files correctly transferred, sometimes tens of
files and sometimes only a few, lftp "hangs".  That is, it stops,
looping, using 100% of the cpu, no further files are transferred and
no additional output is generated.  Since the stdout/stderr of lftp
are using buffered output, I am unable to tell at which point the file
transfer stops working.  Nor can I tell why.

strace of the looping process gives no output, so no system calls are
being made.  Numerous ssh processes are running, but they are sitting
in select:

agent    29058 29055  0 18:17 pts/2    00:00:02 ssh -a -x -s -l user hostname 
sftp
agent    29066 29055  0 18:17 pts/3    00:00:02 ssh -a -x -s -l user hostname 
sftp
agent    29068 29055  0 18:17 pts/5    00:00:02 ssh -a -x -s -l user hostname 
sftp
agent    29069 29055  0 18:17 pts/6    00:00:02 ssh -a -x -s -l user hostname 
sftp

$ strace -p 29066
select(8, [4 5], [6], NULL, NULL

This problem did not occur on RHEL4 (lftp 2.6.3).  The problem has
only started happening since we upgraded systems to RHEL5.

Any ideas?

        -- John

-- 
John Relph <[EMAIL PROTECTED]>
NOAA/NESDIS/National Oceanographic Data Center

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