Bug 202044

Summary: ssRawCpu* stays on 2^32-1 forever.
Product: Red Hat Enterprise Linux 3 Reporter: James Lamb <james.lamb>
Component: net-snmpAssignee: Radek Vokál <rvokal>
Status: CLOSED ERRATA QA Contact:
Severity: high Docs Contact:
Priority: medium    
Version: 3.0CC: james.lamb
Target Milestone: ---   
Target Release: ---   
Hardware: i386   
OS: Linux   
Whiteboard:
Fixed In Version: RHBA-2007-0458 Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2007-06-11 18:38:21 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:

Description James Lamb 2006-08-10 15:20:22 UTC
Description of problem:


When I query a RH ES v3 u7 server using snmp for idle ticks which should
indicate that the server is loaded or not. After a large amount of uptime (circa
240days) the servers all report the idle ticks not increasing even though the
server has been idle for some time. If I run the following command  awk '/^cpu /
{print $5}' /proc/stat I can see that the counter is still incrementing but
snmpd reports

UCD-SNMP-MIB::ssCpuRawIdle.0 = Counter32: 4294967295

When I query with the following OID enterprises.ucdavis.systemStats

No matter how long the system is up it will always report the variable
4294967295, even if the system is 100% idle.

I have done some extensive research and it looks as though the problem is
resolved with the following patch from the net-snmp cvs.

http://net-snmp.cvs.sourceforge.net/net-snmp/net-snmp/agent/mibgroup/ucd-snmp/vmstat.c?r1=5.7&r2=5.8



How reproducible:
Very Easy.

Steps to Reproduce:

snmpwalk -v 2c -c private localhost  enterprises.ucdavis.systemStats | grep Idle
; sleep 60 ; snmpwalk -v 2c -c private localhost 
enterprises.ucdavis.systemStats | grep Idle

  
Actual results:

UCD-SNMP-MIB::ssCpuIdle.0 = INTEGER: 99
UCD-SNMP-MIB::ssCpuRawIdle.0 = Counter32: 4294967295


Expected results:

UCD-SNMP-MIB::ssCpuIdle.0 = INTEGER: 99
UCD-SNMP-MIB::ssCpuRawIdle.0 = Counter32: [[4294967295]] 

Where the [[]] Number should have incremented as the server is idle.



Additional info:
This problem appears to occur in all Redhat EL v3 servers that we have with huge
uptime. 

After reading around on the internet I have found several people with an
identical issue. From what It looks like this is the patch to resolve the problem. 

http://net-snmp.cvs.sourceforge.net/net-snmp/net-snmp/agent/mibgroup/ucd-snmp/vmstat.c?r1=5.7&r2=5.8&diff_format=c

There are also debian users with similar problems.

http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=308018

Comment 1 Radek Vokál 2006-08-11 06:28:21 UTC
Thanks, I propose this issue for next update. 

Comment 7 Red Hat Bugzilla 2007-06-11 18:38:21 UTC
An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on the solution and/or where to find the updated files,
please follow the link below. You may reopen this bug report
if the solution does not work for you.

http://rhn.redhat.com/errata/RHBA-2007-0458.html