I've added the following summary to the details section of the 1pager:
memcached is a high-performance, distributed memory object caching
system, generic in nature, but intended for use in speeding up
dynamic web applications by alleviating database load.
Danga Interactive developed memcached to enhance the speed of
LiveJournal.com, a site which was already doing 20 million+
dynamic page views per day for 1 million users with a bunch of
webservers and a bunch of database servers. memcached dropped the
database load to almost nothing, yielding faster page load times
for users, better resource utilization, and faster access to the
databases on a memcache miss.
How it Works
First, you start up the memcached daemon on as many spare machines
as you have. The daemon has no configuration file, just a few
command line options, only 3 or 4 of which you'll likely use:
# ./memcached -d -m 2048 -l 10.0.0.40 -p 11211
This starts memcached up as a daemon, using 2GB of memory, and
listening on IP 10.0.0.40, port 11211. Because a 32-bit process
can only address 4GB of virtual memory (usually significantly
less, depending on your operating system), if you have a 32-bit
server with 4-64GB of memory using PAE you can just run multiple
processes on the machine, each using 2 or 3GB of memory.
Now, in your application, wherever you go to do a database query,
first check the memcache. If the memcache returns an undefined
object, then go to the database, get what you're looking for, and
put it in the memcache.
Dan Mick wrote:
> David.Comay at Sun.COM wrote:
>
>>> I have asked Roy to provide a one paragraph summary that I can add to
>>> the 1pager. But in the meantime, you can read
>>> http://www.danga.com/memcached/ and
>>> http://en.wikipedia.org/wiki/Memcached
>>
>>
>> Also as this is a version update to a previous case, you can find out
>> more about memcached by looking at the earlier case, LSARC/2007/385.
>> In particular,
>>
>> LSARC/2007/385/commitment.materials.final/questionnaire.txt
>>
>> dsc
>
>
> yes, although one sentence in the current case is pretty low-cost.
