[Building Sakai] Sakai Instances 100% CPU Usage

[Mark J. Norton]

Some related information:

http://www.wired.com/wiredenterprise/2012/07/leap-second-glitch-explained/

The Amazon Cloud crashed.  Problem related to the hrtimer function in 
Lunix distros.

  - Mark


On 7/3/2012 11:22 AM, Beth Kirschner wrote:
> There was a leap second this weekend (June 30, 8pm EDT) which we 
> believe caused all our servers to hit 100% CPU usage simultaneously. 
> Has anyone else in the Sakai community seen this? We're running:
> Linux 2.6.32-220.17.1.el6.x86_64
> java version "1.6.0_22"
>
> Thanks,
> - Beth
>
> Begin forwarded message:
>>
>>
>>
>>   URL =
>>   http://wiki.os-ux.com/java-leap-second-bug-30-june-1-july-2012-fix/
>>
>>
>>
>>   java leap second bug -- 30 June / 1 July 2012 -- fix
>>   ------------------------------------------------------------------------
>>
>> If your java applications suddenly started to use 100% CPU, you've 
>> hit java leap second bug (actually it's a bug in Linux kernel, just 
>> java programs seem to be severely affected).
>>
>> First, you may check if you have the following in your dmesg:
>>
>> |
>> [10703552.860274] Clock: inserting leap second 23:59:60 UTC|
>>
>> Fortunately the fix is straightforward:
>>
>> |/etc/init.d/ntpd stop
>> date -s "$(date)"|
>>
>> |/etc/init.d/ntpd start|
>>
>> (the other suggested way around the web would be |date `date 
>> +"%m%d%H%M%C%y.%S"`|, having the same effect).
>>
>> You don't have to restart your java applications (tomcat, solr, 
>> wowza, or whatever using java); it should be enough to run the above 
>> commands.
>>
>> You may want to enable ntp the next day (there were some reports that 
>> enabling it makes java misbehave on some installations).
>>
>> Apparently this issue has knocked down lots of Linux servers running 
>> Debian, Ubuntu, CentOS and the like around the globe!
>>
>> read more <https://access.redhat.com/knowledge/articles/15145>
>>
>> (via wpkg.org 
>> <http://blog.wpkg.org/2012/07/01/java-leap-second-bug-30-june-1-july-2012-fix/>)
>>
>> Author: Vucomir Ianculov on July 3, 2012
>> Category: Linux / Unix <http://wiki.os-ux.com/category/linux-unix/>
>> Tags: date <http://wiki.os-ux.com/tag/date/>, java 
>> <http://wiki.os-ux.com/tag/java/>, kernel 
>> <http://wiki.os-ux.com/tag/kernel/>, linux 
>> <http://wiki.os-ux.com/tag/linux-2/>, ntpd 
>> <http://wiki.os-ux.com/tag/ntpd/>, Zimbra 
>> <http://wiki.os-ux.com/tag/zimbra/>
>> Protected by Copyscape DMCA Copyright Detector 
>> <http://www.copyscape.com/dmca-copyright-protection/>
>>
>
>
>
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