[wp-hackers] Load Balancing | Media Uploads to Multiple Servers

[Steve Pellham]

Very similar to what we are implementing... to be a bit more descriptive...
the remote DC can be used for LB (geo/weighted) and act as a complete
failover site in an extreme case where the main data center (comm circuit
redundancy unavailable in our small area) is completely cutoff from the
world (happened this past January!).

########## main datacenter ############
-main web server

-main db master
-- replicated slave0
-- replicated slave1
-- replicated slave2
...etc...


Adding this...
############ remote datacenter ##############
-remote web server (synced to main web server real-time via rsync, csync,
subversion for apps)

- remote master db (slave of  main db master)
-- remote slave0 (slave of remote master db)

Make sense?  Just remembered the Yoast post on using a CDN for content such
as images, etc...  I guess that could be what Eric suggested earlier... that
could be considered, but the same questions still apply: does the CDN being
used have a single?

I know there are no perfect solutions and no such thing as 100% uptime, but
I'm making a best effort.

great info -- SP

2009/8/5 Pixline › Paolo Tresso <supporto at pixline.net>

> I fail to see how not replicating data (mysql, application, content data)
>> across multiple servers prevents a single point of failure.
>>
>
> + 1 definitely. you really trust your hardware if you think so.. :-)
>
> For what it's worth, I've succesfully used this setup several times:
>
> - main web server (fine tuned apache, or better lighttpd/nginx if you have
> enough experience)
> - at least two servers for static files. you can balance them under a
> subdomain or have more subdomains and switch users according to location or
> whatever
> - main db server (for writes) and 2+ replicated for reads. or if you're
> brave enough, consider mysql_proxy.
> - backup server to store everything you can (backups are never enough).
> offsite, or with another provider. I've used often rsync.net services.
>
> in some heavy traffic environment, we tend to use a pfsense.org box to
> deal with vpn's, load balancing and global firewalls. really powerful, and
> worth a look if it match your needs.
>
> hope it helps
> p.
>
>