Lots of DB requests when cache expires...

[Brad Oaks]

Hi Olga,

You ask a good question.  Have a look at the solution described here
http://www.socialtext.net/memcached/index.cgi?faq#how_to_prevent_clobbering_updates_stampeding_requests
and let us know if that works for you.

The solution that I had come up with and still use is described at
http://lists.danga.com/pipermail/memcached/2007-July/004810.html

Best of luck,
--bradoaks

On 10/10/07, Olga Khenkin <olga at metacafe.com> wrote:
> Hi,
>
> When some popular object expires from memcached, all its customers try to
> retrieve the object from database simultaneously, and the database becomes
> overloaded.
>
> If this object is requested about 100 times in a minute, and if the process
> of receiving it from DB, processing and storing in cache takes about a
> minute, then the database receives 100 identical queries.
>
> Do you have this problem? How do you handle it?
>
> Thank you in advance,
>
> Olga.