[Systems] aslo cluster progress

[Bernie Innocenti]

On Sat, 2010-03-13 at 10:58 -0600, David Farning wrote:

> Yes, we require master-master.  The goal here is if one machine to go
> down, the other takes over.  Master-Master is the only arrangement in
> which the second machine can take over the writes.

Multi-master is really hard, IMHO. It even requires a special table
format which probably performs worse and doesn't support some of the
features of InnoDB.

I was told that MySQL's master-slave configuration now supports
automatic turn-around in case the master disappears. I can imagine
scenarios in which such as setup like this might loose a transaction or
two, but I guess we don't care since we're not running a bank.


> As an FYI, as you predicted, database load is not going to be a
> problem for a _long_.  I think we can handle about 10 php servers with
> each database server.  Cache 1, memchached, has a hit rate in the mid
> 80%. Cache 2, the mysql cache, has a hit rate in the low 90%.  I just
> did a mysql dump and the size of the data base was just under 100MB 
> 
Good. I've seen the workload on memcached increase a lot over the past 3
days. What happened? Did we turn on more aggressive caching?

I'm very glad the load on Sunjammer is lower than before. Do you think
we may need to setup one more web node on housetree?

For NFS, I might configure a VPN or something like that.


> Now that the basic plumbing is in place it will be pretty time
> effective for experienced admins like you and hhardy to review and
> improve the manifests.

I've just had a look at the proxy configuration. Is it using only one
web node on treehouse, or is there also an implicit pass-through to
sunjammer?


-- 
   // Bernie Innocenti - http://codewiz.org/
 \X/  Sugar Labs       - http://sugarlabs.org/