tracking online user count under memcached
skylos at gmail.com
Fri Jun 17 21:35:33 PDT 2005
You certainly could cache for an acceptably granular period of time
the current logins.
if fail to fetch login_count
store login_count in cache with expiration
thus cutting down the silly queries for login counts to an acceptable
interval. Fast results for your count, granularity as small as you
like (run the query every 5 seconds, the db won't care). Performance
from memcached, reliability from the db.
On 6/17/05, Xuefer <xuefer at gmail.com> wrote:
> > So say your code gets cookie 332233, if memcached doesn't have data,
> > it yanks from DB.. Otherwise, it yanks data from memcached for
> > relevant needs. at some point during the request it checks exist of
> > sky-STORED - if it doesn't exist, it dumps any changes/updates as
> > relevant into the database, and recreates sky-STORED with another 60
> > second expiration.
> > You cut DB hits mostly, and you still have minute-resolution on
> > session activity. Performance from memcached, reliability from db.
> > Skylos
> great, that's what i need.
> (i was hoping there is a way to do something like
> session_onstart/onend, as doing a "select count(*) from table where
> location=..." is a bit slow)
> i'll look into it
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