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Build Identifier:
We are running on all our systems saslauthd.service, this one was installed
from the official opensuse-repository[1].
Sometimes, the CPU-usage on all systems is getting higher until our systems
reach the critical point of fluent usage and load average of < 200.
Please also take a look to the attached strace-output from the hanging process
which consumes a huge amount of cpu[3]
To workaround this situation, we are monitoring the saslauthd-processes for the
CPU-time and after reaching a value of 10, the services gets restarted.
>From this point the situation takes a couple of hours to reach this critical
point again.
Looking for same or similar issues bright us to the cyrus mailing list with the
same issue description[2].
As the maintainer wrote, issue was fixed in version 2.1.27.
Our analyses shows, that the opensuse cyrus-sasl-saslauthd-package was build
from source-package cyrus-sasl-2.1.26.tar.gz. This one was published in 2012.
So the issue seems to be still present in the sources.
We have invested a lot of time to analyse this issue and have all this results
attached to this report to receive hopefully in short time a fixed version of
cyrus-sasl-saslauthd.
If you need some additional information to this issue, please let me know it.
Thank you in advance!
Reproducible: Sometimes
Steps to Reproduce:
1. start saslauthd.service
2. wait some time (requests are going through the service)
3. system load is going continuously higher
4. look for the saslauthd-processes (ps faxu) pick the pid which CPU-time
consumption is higher than 0:00
5. strace on that process is included to this bug report
Expected Results:
Service is running normally with all treads without huge CPU-usage and
resulting impact for the whole system.
[1]Package-version:
Loading repository data...
Reading installed packages...
Information for package cyrus-sasl-saslauthd:
---------------------------------------------
Repository : openSUSE-42.3-Update
Name : cyrus-sasl-saslauthd
Version : 2.1.26-14.1
Arch : x86_64
Vendor : openSUSE
Installed Size : 133.1 KiB
Installed : Yes
Status : up-to-date
Source package : cyrus-sasl-saslauthd-2.1.26-14.1.src
Summary : The SASL Authentication Server
Description :
This daemon is required when using cyrus-sasl in server software that
should authenticate with PAM, for example.
[2] Issue on Cyrus-sasl mailing lis:
https://lists.andrew.cmu.edu/pipermail/cyrus-sasl/2016-November/002914.html
[3] strace output from pid 15542 - see also [4]
15542 select(10, [9], NULL, NULL, {0, 0}) = 1 (in [9], left {0, 0})
15542 read(9, "", 905) = 0
15542 select(10, [9], NULL, NULL, {0, 0}) = 1 (in [9], left {0, 0})
15542 read(9, "", 905) = 0
15542 select(10, [9], NULL, NULL, {0, 0}) = 1 (in [9], left {0, 0})
15542 read(9, "", 905) = 0
[...infinitely...]
[4] running process-tree (you can see the increased cpu-time for the looping
processes)
root 15502 26.7 0.0 54144 2232 ? Rs 19:40 1:03
/usr/sbin/saslauthd -a rimap -c -r -O imapauth.server.com -n 20
root 15540 0.0 0.0 54144 592 ? S 19:40 0:00 \_
/usr/sbin/saslauthd -a rimap -c -r -O imapauth.server.com -n 20
root 15542 32.5 0.0 54144 592 ? R 19:40 1:17 \_
/usr/sbin/saslauthd -a rimap -c -r -O imapauth.server.com -n 20
root 15544 0.0 0.0 54144 592 ? S 19:40 0:00 \_
/usr/sbin/saslauthd -a rimap -c -r -O imapauth.server.com -n 20
root 15547 0.0 0.0 54144 592 ? S 19:40 0:00 \_
/usr/sbin/saslauthd -a rimap -c -r -O imapauth.server.com -n 20
root 15548 0.0 0.0 54144 592 ? S 19:40 0:00 \_
/usr/sbin/saslauthd -a rimap -c -r -O imapauth.server.com -n 20
root 15549 8.6 0.0 54144 592 ? R 19:40 0:20 \_
/usr/sbin/saslauthd -a rimap -c -r -O imapauth.server.com -n 20
root 15551 0.0 0.0 54144 592 ? S 19:40 0:00 \_
/usr/sbin/saslauthd -a rimap -c -r -O imapauth.server.com -n 20
root 15552 0.0 0.0 54144 592 ? S 19:40 0:00 \_
/usr/sbin/saslauthd -a rimap -c -r -O imapauth.server.com -n 20
root 15553 0.0 0.0 54144 592 ? S 19:40 0:00 \_
/usr/sbin/saslauthd -a rimap -c -r -O imapauth.server.com -n 20
root 15554 0.0 0.0 54144 592 ? S 19:40 0:00 \_
/usr/sbin/saslauthd -a rimap -c -r -O imapauth.server.com -n 20
root 15555 0.0 0.0 54144 592 ? S 19:40 0:00 \_
/usr/sbin/saslauthd -a rimap -c -r -O imapauth.server.com -n 20
root 15558 0.0 0.0 54144 592 ? S 19:40 0:00 \_
/usr/sbin/saslauthd -a rimap -c -r -O imapauth.server.com -n 20
root 15560 0.0 0.0 54144 592 ? S 19:40 0:00 \_
/usr/sbin/saslauthd -a rimap -c -r -O imapauth.server.com -n 20
root 15561 0.0 0.0 54144 592 ? S 19:40 0:00 \_
/usr/sbin/saslauthd -a rimap -c -r -O imapauth.server.com -n 20
root 15562 0.0 0.0 54144 592 ? S 19:40 0:00 \_
/usr/sbin/saslauthd -a rimap -c -r -O imapauth.server.com -n 20
root 15563 0.0 0.0 54144 592 ? S 19:40 0:00 \_
/usr/sbin/saslauthd -a rimap -c -r -O imapauth.server.com -n 20
root 15564 0.0 0.0 54144 592 ? S 19:40 0:00 \_
/usr/sbin/saslauthd -a rimap -c -r -O imapauth.server.com -n 20
root 15565 0.0 0.0 54144 592 ? S 19:40 0:00 \_
/usr/sbin/saslauthd -a rimap -c -r -O imapauth.server.com -n 20
root 15566 0.0 0.0 54144 592 ? S 19:40 0:00 \_
/usr/sbin/saslauthd -a rimap -c -r -O imapauth.server.com -n 20
[5] we are using the following configuration (/etc/sysconfig/saslauthd)
SASLAUTHD_AUTHMECH="rimap -c -r -O imapauth.server.com"
SASLAUTHD_THREADS=20