What are you guys using to cluster the LVS servers? Is that
functionality native to LVS?
Also, I've come across "fastcgi" a lot in researching this and I'm
having trouble understanding exactly what it is.
The fastcgi website makes it sound like it's almost a mod_perl
replacement and another approach to executing perl code in a web
environment, however a lot of the webservers that implement fastcgi keep
referring to it almost like it's a protocol that proxy servers use to
talk to their back end app servers... I'm a bit confused about what it
is, what situations it's used in, and if it provides me any benefit if
I'm already married to mod_perl.
I know this probably isn't the best place to ask this question, but can
someone clarify this for me?
On 4/15/2010 8:04 PM, Cees Hek wrote:
On Thu, Apr 15, 2010 at 4:38 PM, Cosimo Streppone<cos...@streppone.it> wrote:
In data 15 aprile 2010 alle ore 05:11:15, Brad Van Sickle
<bvs7...@gmail.com> ha scritto:
LVS does sound interesting but in your infrastructure layout aren't your
single LVS load balancers single points of failure?
I simplified a bit too much :)
Every LVS machine has a hot-spare, and you can perform
manual or automated failover.
Automated failover is said to keep your connections running
while migrating them over to the backup lvs. We have never
had a failure, just manual failover due to upgrades, etc...
We use LVS to load balance our reverse proxies as well as our app servers.
- 2 LVS servers using heartbeat for automatic failover (we are looking
to switch to keepalived instead of heartbeat in the future),
- 3 nginx servers which do content compression and ssl offloading as
well as caching (we don't need 3 of them but we like the redundancy
and the ability to drop one without impacting performance)
- 5 app servers running apache and mod_perl
We have just switched to nginx from squid in the last few months and
have been very happy with it. nginx can also deliver static content
directly or act as a FastCGI frontend (relaying the requests to
backend app servers) as well as many other things. But our main
reason for switching to nginx was the ability to offload SSL requests
and remove that complexity from the app servers (we previously used
squid as our reverse proxy which can't do SSL offloading).
nginx can do it's own load balancing as well but we preferred to use
our existing LVS infrastructure to handle that for us.
As an added bonus, LVS also load balances our mail cluster...
Cheers,
Cees Hek
