Re: mod_perl in larger scale environments

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<[email protected]>  wrote:
>    
>> In data 15 aprile 2010 alle ore 05:11:15, Brad Van Sickle
>> <[email protected]>  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
>