Mike McGrath wrote:
So for those wondering what I've done with the wiki upgrade,
I've made
a simple diagram.
Cool, what software did you use for the diagram?
As we get more hardware and resources you can see where we're
headed
as far as HA goes in our environment. I'm still trying to acquire a
NAS or SAN for us, this will make what we need to do much easier.
Also at the application layer once we get in a Xen environment we can
add and remove app servers easily without having to expand the number
of proxy servers we have until they get overloaded. I'm still
experimenting with various things but right now app2 is our biggest
SPOF[1] as it houses the wiki and shares it with app1.
The proxy servers are using mod-rewrite [P] to proxy services.
* Which mod_cache are you using?
o pro: mod_disk_cache is able to share cache among worker threads
con: a response will not go out until the full response is
written to disk
o pro: mod_mem_cache is *fast*
con: cache is not shared among workers
* We should really be using squid.
Basically the load balancer balances between proxy[1-2] and each
proxy in turn proxies to app[1-2].
What load balancer are we using?
Instead of proxy1 -> app1, proxy2 -> app2. The proxy servers
will
also mount or contain copies of static content (like /extras, or
favicon.ico)
There are many tweaks to be made to make this useful and hands-off HA,
but this is a good first step for us. As always I'm interested in
discussion so send it my way.
-Mike
[1] Our load balancer may also be a SPOF, not sure.
Unless there are multiple
paths, I would expect so also.
;; QUESTION SECTION:
;fedoraproject.org. IN A
;; ANSWER SECTION:
fedoraproject.org. 959 IN A 209.132.176.120
Looks to be the case, unless there is something at the network level.
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So cool.
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Jonathan