sishen_freecity at 126.com
Tue Oct 24 16:51:31 UTC 2006
Bash Coder wrote:
> On 10/24/06, *Moritz Maisel* <maisel at sipgate.de
> <mailto:maisel at sipgate.de>> wrote:
> If there were 3 Servers X, Y and Z. A client uses cache Y. After
> that Y goes
> down. Now the client takes another cache. When B comes up again it
> is again
> used by the client and we get outdated data ...
> I would have thought that if Y goes down, the client goes to the
> database(s). At least that's what I'm planning. If the client can't
> connect it will go directly to the source. I mean, that's what the
> client would have to do anyway if it could connect to the sever but
> the server didn't have the data cached.
Maybe you can see Tugela_Cache
(http://meta.wikimedia.org/wiki/Tugela_Cache), which use bdb as its
backend storage. When you restart the server, you can reload the data
from the database. I think this way have two shortcoming:
1. it is time-consuming. it use bdb cache for memory management, which
is less effective as slab+hash.
2. When the server down, the client is just to choose to use another
server, when you reload the data from db, the data is duplicate.
> I'm a new user, and I love the idea of memcached but I don't think it
> was designed to be reliable. It's not the Google filesystem. That's
> cool, as long as I don't architect my system as though it were.
keep the memcached simple and easy-maintenance, :)
> - Bash
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