Date: Wed, 20 Sep 2000 14:44:21 -0300 (ART) From: Fernando Schapachnik <fpscha@ns1.via-net-works.net.ar> To: FreeBSD-gnats-submit@freebsd.org Subject: kern/21424: Blocking issue while regenerating aliases on 4.1-RELEASE Message-ID: <200009201744.OAA10111@ns1.via-net-works.net.ar>
next in thread | raw e-mail | index | archive | help
>Number: 21424
>Category: kern
>Synopsis: Blocking issue while regenerating aliases on 4.1-RELEASE
>Confidential: no
>Severity: serious
>Priority: high
>Responsible: freebsd-bugs
>State: open
>Quarter:
>Keywords:
>Date-Required:
>Class: sw-bug
>Submitter-Id: current-users
>Arrival-Date: Wed Sep 20 10:50:00 PDT 2000
>Closed-Date:
>Last-Modified:
>Originator: Fernando Schapachnik
>Release: FreeBSD 4.1-RELEASE i386
>Organization:
VIA NET.WORKS ARGENTINA
>Environment:
SMP 4.1-RELEASE:
CPU: Pentium III/Pentium III Xeon/Celeron (731.02-MHz 686-class CPU)
Origin = "GenuineIntel" Id = 0x683 Stepping = 3
Features=0x383fbff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA
,CMOV,PAT,PSE36,MMX,FXSR,XMM>
real memory = 536854528 (524272K bytes)
Busy mail server running the stock sendmail system.
>Description:
First thing I noticed was that newaliases was getting hung.
Further investigation showed the problem was
~majordom/aliases.majordom.db
Running makemap hash ~majordom/aliases.majordom <
~majordom/aliases.majordom hunged also.
A fstat showed only sendmail has this file open, and for
reading only.
A ktrace shows:
[...]
87185 makemap CALL open(0xbfbff658,0x622,0x1a4)
87185 makemap NAMI "aliases.majordomo.db"
[a lot of time... sent kill]
87185 makemap PSIG SIGINT SIG_DFL
aliases.majordom.db ends with 0 bytes. Removing the file
solves the problem.
Sometimes same thing happens with virtusertable and similar
aliases-related files.
Today the same happened with access.db. Lsof showed
sendmail 52975 root 7rR VREG 109,196608 0 35980 /etc/mail/access.db
which means sendmail has the whole file locked for reading.
Doing a ps -axl shows lockfs state and a sleeping process
(waiting for a lock, I guess).
>How-To-Repeat:
Run newaliases during busy hours.
>Fix:
Workaround: Remove the .db file and run newaliases/makemap
acordingly.
To avoing concurrency problems, I'm using this script:
#!/bin/sh
dir=/usr/local/sendmail_aliases
# Copy actual alias file to fake dir.
cp /usr/local/majordomo/aliases.majordomo $dir/usr/local/majordomo/aliases.ma
jordomo
cp /etc/mail/alias-de-clientes $dir/etc/mail/alias-de-clientes
cp /etc/mail/aliases $dir/etc/mail/aliases
cp /etc/mail/usertable $dir/etc/mail/usertable
# Regenerate aliases inside the cage.
/usr/sbin/chroot $dir /usr/sbin/sendmail -bi
/usr/sbin/chroot $dir /usr/sbin/makemap hash /etc/mail/usertable < /etc/mail/
usertable
# Put aliases files in its proper place.
cp $dir/usr/local/majordomo/aliases.majordomo.db /usr/local/majordomo/aliases
.majordomo.db
cp $dir/etc/mail/alias-de-clientes.db /etc/mail/alias-de-clientes.db
cp $dir/etc/mail/aliases.db /etc/mail/aliases.db
cp $dir/etc/mail/usertable.db /etc/mail/usertable.db
>Release-Note:
>Audit-Trail:
>Unformatted:
To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-bugs" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?200009201744.OAA10111>