Our site is getting much more complex because we are now going to duplicate web-servers and formal firewalls between them and the internal network. This is causing us a few problems.
Part of the problem is that the webservers really have no knowledge of each other and do not share disks, this means that we have to keep them in sync.
The following are the issues we have defined and possible solutions, any suggested solutions would be appreciated.
1. PHP sessions - Since the session is only written to 1 webserver the session could be lost if they go to the other server. We will write our own session handler which will store the session in the DB, we also considered FTP'ing the file to the other webserver when we wrote it.
2. Publishing Content to the site - We will need to FTP all updates to both webservers. It appears we will have to write a program that Syncs trees via FTP... are there any tools available for this process?
thanks for any input.
Load Balanced Site strategies
Moderator: General Moderators
Well, I am just the developer I am not building the network. My understanding is that they have bought dedicated load-balancing boxes. They are going for ultimate availability so everythings is doubled up and always with more than 1 path.BDKR wrote:Hi Hedge,
Do you have a machine that is doing the actual load balancing? You could build your own loadbalancers for the price of hardware only....we are now going to duplicate web-servers and formal firewalls...
Let me know....
Cheers,
BDKR
ie. duplicate isp's cross-wired into duplicate load balancers which are in turn cross wired to duplicate web servers...
Sounds like they're doing it right. Have they decided on software yet? If they are linux guys and comfortable with it, they can look at the linux lvs and build the system for free. Otherwise, you could use Turbo Cluster for Turbo Linux. Probably the cheapest and best of the commercial solutions out there. I use in the data center I built. It's extremely flexible and works on heterogenous networks. Our transaction servers are W2K based, but everthing else is Linux based.
So you said they are running multiple firewalls? Let me know how they deal with that as there are serious issues to overcome there as well. Using Linux in cluster managers (load balancers), I was able to do some intersting things routing wise at the kernel level, but even still, it required some trickery at the firewall level as well. Something about NAT you could say. Tell them to email me as I'd love to chat with others on this topic. Ours is very close to being 100 percent operative (keep coming up on additional problems that just keep slowing things down) and I'd like to see how others are approaching the high availability issue.
Cheers,
BDKR
So you said they are running multiple firewalls? Let me know how they deal with that as there are serious issues to overcome there as well. Using Linux in cluster managers (load balancers), I was able to do some intersting things routing wise at the kernel level, but even still, it required some trickery at the firewall level as well. Something about NAT you could say. Tell them to email me as I'd love to chat with others on this topic. Ours is very close to being 100 percent operative (keep coming up on additional problems that just keep slowing things down) and I'd like to see how others are approaching the high availability issue.
Cheers,
BDKR