Strange memcached behavior on stress test

Stephen Woodbridge woodbri at
Sun Jun 11 19:01:34 UTC 2006

dormando wrote:
>> So what is going on? Is this the cache fragmentation problem? Is there 
>> a fix for this problem? Other thoughts?
>> Thanks,
>>   -Steve
> Can you give more details on your setup? What platform/OS? 32-bit or 
> 64-bit?

Debian 32bit Sarge with a HUGEMEM kernel patch and 6 GB of memory and 1 
GB configured for memcached. I grew to about 1.5 GB then started 
throwing the errors.

> What were the *exact* errors you were getting on sets? Were the same 
> happening on gets?

The stress test script generated a random sized data packet (1-20KB in 
size) then does a set and an immediate get and compares the set and and 
got value, it counts it as an error if they do not match. this was done 
via a perl script. Sorry, I don't have more specific data, I would have 
to rerun the tests if I can get the server.

> My apologies if you've mentioned this already, but I took a quick glance 
> back and didn't see it.

The Message Subject "Stress Test Script" on 6/9/2005 is the script we 
used for testing.


> -Dormando

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