A couple things popped into my mind when i read this, some may apply
some may not.
I remember hearing that Facebook actually changed the parsing of MySQL
query language to support passing memcache keys across data centers.
This was to prevent an object from being expired/reloaded before the
data actually replicated from one data center to another.
So the SQL would look something like: UPDATE users SET password =
('somepass') EXPIRE memcachekey1, memcachekey2
Maybe someone can speak more to this, I think there was a blog post or
a presentation released from them regarding this.
Also something to look into would be the MySQL UDF functions for
memcached. Last I saw they were available http://www.tangent.org/,
although the site seems to be down for me right now.
Matt
On Nov 11, 2008, at 12:41 PM, Brad Fitzpatrick wrote:
[+memcached list]
On Tue, Nov 11, 2008 at 12:09 PM, Lei Gao <[EMAIL PROTECTED]> wrote:
Hi Brad,
I am considering integrating memcached tightly with a database,
mysql or oracle. I.e. I want the database to actively send updates
to the memcached server. One way to do this is to create a memcached
client program that gets the data from the database and store them
into the memcached server via the client set API.
Some concerns with this approach are 1. the client API seems limited
to what I want to do in terms of keeping memcached server in sync.
with the database; 2. the client API might be less efficient for
loading data onto the server if the in-coming rate is high.
Is it possible to create a memcached server extension to interface
directly with the database?
Thanks in advance.
Lei
On Mon, Jun 23, 2008 at 4:00 PM, Brad Fitzpatrick <[EMAIL PROTECTED]>
wrote:
It doesn't.
If that matters for you, don't cache that entity, or set a low
expiration timeout.
On Mon, Jun 23, 2008 at 3:52 PM, Lei Gao <[EMAIL PROTECTED]> wrote:
Hi Brad,
I am an academic researcher in computer sciences at UT Austin. I
have a simple question about memcached. (I got your email address at
the end of one of your articles about memcached). How does the
memcached handle the situation where the databased is updated from a
non-memcached-aware party? For instance, my system admin updates the
some database records that are cached in one or more memcached
instance, how do those instances refresh themselves? (Another
example is when the database is replicated and updates take place on
all replicas.)
Thanks,
--
Lei Gao
--
Lei Gao
