All - seeing the issue with history files we thought we should alert you
to a known "bug" with the history command and history file in RHEL that
caused major slow down and eventual lock up of our system. It is a known
problem in RHEL 2.1, 3, 4, 5 and 6. We only ran into it on RHEL 6.2 but
the remedy was to add "set history=0" in our .cshrc
We also added an alias h50 "set history=50" so that when you open an
terminal window and type h50 it will start remembering your commands.
Klunky yes, but at least our workstations don't lock up. I had to log on
to the REHL customer portal and search for "42739" to get this printout -
which I cut/paste into this email. I hope it translates well in your
email viewer.
See below - although not sure it will address your original issue. Pete
-------------------------------------------
Currently Being Moderated
A system slows down due to a .history file
Article ID: 42739 - Created on: Oct 5, 2010 10:54 PM - Last Modified: Jan
23, 2011 9:09 PM
Issue
The data in the file ".history" becomes malformed and its file size gets
larger and larger.
Each command history should be recoded in the file with a timestamp line
a command entry line which should end with EOL(End Of Line).
Example of normal .history file:
$ cat -n .history
1 #+1289787344
2 set
A timestamp and a run command entry are not recorded by turns. Not a run
command entry but a timestamp is recorded unexpectedly (see the line 4).
Additionally, some entries are merged unexpectedly (see the line 6 and 7
below).
Example of malformed .history file :
$ cat -n .history
1 #+1289787344
2 test
3 #+1289787367
4 1289787366
5 #+1289787367
6 128978#+12897#+1289#+12897test
7 #+1289#+12897testls##+1289787401l12#+1289787402
8 st
A system slows down because csh uses a lot of memory to read such a large
.history file.
Environment
Red Hat Enterprise Linux 2.1, 3, 4, 5, and 6
Resolution
This issue will be addressed in "Bug 648592 - .history file gets corrupted
if several scripts run at once"
There is a temporary workaround by disabling the history of csh
Set the one of the following lines in ~/.cshrc or on the command line:
unset savehist
OR
set savehist=
Root Cause
The main issue which should be fixed is that tcsh does not handle
~/.history file exclusively. The "merge" option causes possibility of a
little more unexpected behaviour with warning mentioned in man page
regarding the "-S" built-in command:
...
history [-hTr] [n]
history -S|-L|-M [filename] (+)
history -c (+)
...
With -S, the second form saves the history list to file-
name. If the first word of the savehist shell variable is
set to a number, at most that many lines are saved. If the
second word of savehist is set to ?merge?, the history list
is merged with the existing history file instead of replac-
ing it (if there is one) and sorted by time stamp. (+)
____Merging is intended for an environment like the X
Window
System with several shells in simultaneous use. Currently
it succeeds only when the shells quit nicely one after
another.____
Additionally, both a value greater than 0 and "merge" option are set to
savehist on csh and this is the default setting in Red Hat Enterprise
Linux 5.4 or later:
$ set | grep savehist
savehist (1024 merge)
From: Greg Stossmeister <gstoss@xxxxxxxx>
To: gembud@xxxxxxxxxxxxxxxx
Date: 04/30/2012 03:48 PM
Subject: Re: [gembud] Generating NEXRAD radar imagery with gpmap_gf
Sent by: gembud-bounces@xxxxxxxxxxxxxxxx
Daryl,
I noticed .history was bizarre last week - it had a ton of stuff in it
that didn't look like the normal history stuff I was used to seeing. We
deleted it this morning and I set my .cshrc to only save the last 40
commands.
Greg
On Apr 30, 2012, at 1:40 PM, daryl herzmann wrote:
>
> Offline... How large is your ~/.history file?
>
> daryl
>
> On Mon, 30 Apr 2012, Greg Stossmeister wrote:
>
>> Daryl,
>> No each process creates a temporary working subdirectory to run in
based on the process id.
>>
>> Greg
>>
>> On Apr 30, 2012, at 1:23 PM, daryl herzmann wrote:
>>
>>> Greg,
>>>
>>> Are all these processes running out of the same CWD (directory)? Try
creating temp directories for each process and run the code from those
directories.
>>>
>>> daryl
>>>
>>> On Mon, 30 Apr 2012, Greg Stossmeister wrote:
>>>
>>>> Daryl,
>>>> I have several shell scripts that I'm running out of cron every 5
minutes. Each shell script runs 10 gpmap_gf processes in sequence. I've
tried running 1 - 6 scripts at a time. This typically works fine during
the day with one of the these scripts completing in about 2 minutes. As
evening comes on they take longer and longer to run and it seems like that
take more and more memory. From the "top" command the scripts often use
500-800 MB of memory but in the evening this seems to mushroom to > 3GB
per script. The load on the machine at night from these scripts alone
jumps to >30 and by morning the machine usually dies with out of memory
errors even though I'm automatically killing the scripts when they run
longer than 2 minutes.
>>>>
>>>> Looking at /var/log/debug.log I'm seeing segfault errors:
>>>>
>>>> Apr 26 17:07:25 sferic kernel: gpmap_gf[2164]: segfault at 0 ip
000000392692ff7f sp 00007fff8d981128 error 4 in
libc-2.12.so[3926800000+186000]
>>>> Apr 26 17:07:25 sferic abrt[2179]: saved core dump of pid 2164
(/export/ldm/home/gempak/GEMPAK6.4.0/os/linux64/bin/gpmap_gf) to
/var/spool/abrt/ccpp-201
>>>> 2-04-26-17:07:25-2164.new/coredump (827392 bytes)
>>>> Apr 26 17:07:25 sferic abrtd: Directory
'ccpp-2012-04-26-17:07:25-2164' creation detected
>>>> Apr 26 17:07:25 sferic kernel: gpmap_gf[2239]: segfault at 0 ip
000000392692ff7f sp 00007ffffd173658 error 4 in
libc-2.12.so[3926800000+186000]
>>>> Apr 26 17:07:25 sferic kernel: gpmap_gf[2242]: segfault at 0 ip
000000392692ff7f sp 00007fff8f4df6f8 error 4 in
libc-2.12.so[3926800000+186000]
>>>> Apr 26 17:07:25 sferic kernel: gpmap_gf[2247]: segfault at 0 ip
000000392692ff7f sp 00007fff73574d18 error 4 in
libc-2.12.so[3926800000+186000]
>>>> Apr 26 17:07:25 sferic kernel: gpmap_gf[2261]: segfault at 0 ip
000000392692ff7f sp 00007fff8bda1358 error 4 in
libc-2.12.so[3926800000+186000]
>>>> Apr 26 17:07:25 sferic kernel: gpmap_gf[2245]: segfault at 0 ip
000000392692ff7f sp 00007fff71495a28 error 4 in
libc-2.12.so[3926800000+186000]
>>>> Apr 26 17:07:25 sferic kernel: Pid 2245(gpmap_gf) over
core_pipe_limit
>>>> Apr 26 17:07:25 sferic kernel: Skipping core dump
>>>> Apr 26 17:07:25 sferic abrt[2260]: not dumping repeating crash in
'/export/ldm/home/gempak/GEMPAK6.4.0/os/linux64/bin/gpmap_gf'
>>>> Apr 26 17:07:25 sferic abrt[2279]: not dumping repeating crash in
'/export/ldm/home/gempak/GEMPAK6.4.0/os/linux64/bin/gpmap_gf'
>>>> Apr 26 17:07:25 sferic kernel: gpmap_gf[2289]: segfault at 0 ip
000000392692ff7f sp 00007fffca7118a8 error 4 in
libc-2.12.so[3926800000+186000]
>>>> Apr 26 17:07:25 sferic kernel: gpmap_gf[2286]: segfault at 0 ip
000000392692ff7f sp 00007fffef00ac98 error 4 in
libc-2.12.so[3926800000+186000]
>>>> Apr 26 17:07:25 sferic kernel: gpmap_gf[2303]: segfault at 0 ip
000000392692ff7f sp 00007fff92019618 error 4 in
libc-2.12.so[3926800000+186000]
>>>> Apr 26 17:07:25 sferic kernel: Pid 2303(gpmap_gf) over
core_pipe_limit
>>>>
>>>> Greg
>>>>
>>>> On Apr 30, 2012, at 12:10 PM, daryl herzmann wrote:
>>>>
>>>>> On Mon, 30 Apr 2012, Greg Stossmeister wrote:
>>>>>
>>>>>> Does anyone generate a lot of individual NEXRAD level III products
with gpmap_gf? I'm trying to generate real-time plots of NOQ Reflectivity
and NOU Velocity from 30 radars in the midwest and its crashing my server
after a few hours, even when I only run 3 plots at a time. I'm running
GEMPAK6.4.0 on a RHEL 6 machine with 64 GB of memory. I'm wondering what
I'm doing wrong and if someone has a better way of doing this.
>>>>>
>>>>> crashing your server, how? Exhausting memory? kernic panic? Are
the processes not going away once running them? How are you running them?
>>>>>
>>>>> daryl
>>>>>
>>>>> --
>>>>> /**
>>>>> * Daryl Herzmann
>>>>> * Assistant Scientist -- Iowa Environmental Mesonet
>>>>> * http://mesonet.agron.iastate.edu
>>>>> */
>>>>
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