[gigabit]

Do we have to use OCO (http://help.ovh.co.uk/Oco) for dead servers to be removed from the cluster automatically? Or is there any other monitoring going on?

[Myatu]

rsync isn't good in a load balanced environment and will lead to a lot of headaches.

As Andy noted, either use a central storage (could lead to a bottleneck, but look into GlusterFS for file storage, which is what I use) or replicate the server using DRBD (see http://www.drbd.org/).

[gigabit]

Thanks Andy, MySQL was gona be my next question too

[Andy]

rsync would be the best option I think.

You could also have a central storage where both servers load from rather than replicating but then you rely heavily on the disks on that server being able to cope with requests from your load balanced cluster.

Databases shouldn't be synced with rsync, they should be on their own server which the cluster accesses.

[gigabit]

What would be the best way to keep files on all servers upto date? Say you have a forum running across 2 servers and someone uploads an avatar, how would you get that to sync to the other server magically?

[bago]

Mark,

thanks for the information. Can you tell me which system is used for load balancing? Then I can further research this. What Bago wrote seems to indicate that there is some IP caching going on.

Peter

If you already have 2 servers it is easy to simply add a new ip load balancer and do some real test.

If I understood OVH architecture they uses Cisco switches/routers, so this could be the standard IOS load balancing.

[PCDiver]

Mark,

thanks for the information. Can you tell me which system is used for load balancing? Then I can further research this. What Bago wrote seems to indicate that there is some IP caching going on.

Peter

[bago]

Hello Mark,

Is it possible to use the OVH IP-loadbalancing solution for a set of windows servers running mainly IIS? My IIS application requires that users stick to the host they first connected to (session info). If this stickyness isn't supported then I'm probably better of using DNS round robin. DNS RR will work because the client caches the DNS entry.

Thanks,

Peter

I tested it and it seems that a client connecting to a web server behind the loadbalancer keeps be routed to the same server. It probably don't care of session but I saw that while I browse my website all of my requests are done to the same physical server. If I open an ssh connection it is opened to the same server I was browsing. If I restart my router (so I get a new IP) I'm often switched to the other server. So no session stickiness, but it will work for most services using it's own "IP session".

[marks]

Firstly, in Windows you cannot run OcO, so it wouldn't have the availability to detect which servers are down and which up.

Secondly: I'm afraid that this session "stickyness" is not possible with the Load Balancing. As you said, the IPs to access the server is always the same and there is nothing to keep track of the already stablish connections

For you applications, it's better to use Round Robin then.

[PCDiver]

It's a per-IP load balancing infrastructure, or said in other words: DNS load balancing. There is no port managing

You create the infrastructure in your manager with the servers you want to and you install OcO (http://help.ovh.com/Oco) so the manager can keep track of what's servers are up and available for the load balancing system to use it.

After that, you do have to install the IP in the servers, so yes, if yuo have iptables configured in each servers, you should use rules with destination equal to your IP load balancing.

Hope this helps

Hello Mark,

Is it possible to use the OVH IP-loadbalancing solution for a set of windows servers running mainly IIS? My IIS application requires that users stick to the host they first connected to (session info). If this stickyness isn't supported then I'm probably better of using DNS round robin. DNS RR will work because the client caches the DNS entry.

Thanks,

Peter

[marks]

It's a per-IP load balancing infrastructure, or said in other words: DNS load balancing. There is no port managing

You create the infrastructure in your manager with the servers you want to and you install OcO (http://help.ovh.com/Oco) so the manager can keep track of what's servers are up and available for the load balancing system to use it.

After that, you do have to install the IP in the servers, so yes, if yuo have iptables configured in each servers, you should use rules with destination equal to your IP load balancing.

Hope this helps

[gigabit]

If i was to use OVH load balancing does every port get forwarded through the load balancer or can you define just 80/443 etc?

Would i need to assign the load balancer IP to every server? And I also use iptables with the "destination IP" set, so would i also need to use the load balancer IP in there too? Or would the servers only see requests directed at their main IPs?