| christopher@baus.net 2005-02-26, 8:42 pm |
| > State is accessible from every node. Requests come in with a session
> cookie, and the web node asks memcache to see if it knows anything abou=
t
> that session. It falls back on the databases if memcache has no
> information on that cookie.
>
> Most of our infrastructure is replaceable and non-unique. Our storage
> nodes are all duplicated through Mogile, our load balancers are identic=
al,
> our web nodes all do the same things, etc. The only parts of the syste=
m
> that can't just be swapped out at will are the databases -- but they ge=
t
> redundancy through having two machines doing the same load with only on=
e
> active at a time.
Interesting. I really like that architecture because it is simple, but
effective. I believe some of the high end load balancers have the abilit=
y
to maintain connections even if a load balancer node catches fire. With
perlbal I guess you'll still drop the connections that are active on that
proxy server. Although that probably isn't that big of a deal given the
application. Web users are used to hitting refresh anyway.
|