There have been allot of discussions lately on WebHosting related forums about “Grid Hosting”
So that got me thinking, how different is a “Grid” from a “Cluster” ?
My first reaction to the whole thing was to get more info on what exactly are hosts calling a “Grid” .. on my Gfx background, we recognize a Grid as an array of computers, linked together to form a “super-computer” for processing power, somehow why would I need to link 1000 servers to offer processing power to a website was not really evident to me, what could you possibly be processing that required that much number crunching ?
The way big players like ebay and others do it (putting it in lame terms) is to have many computers serving the flow of traffic, this is called “load balancing” where traffic is routed to the least overloaded server, so this way you have 100 servers distributing ONE site, but they are not combining the power of 100 servers to process that site, instead each server processes a chunk of the traffic on it’s own.
As as it turns out, thats very much like “Grid” is working as well, you basically get more servers (In this case, VPS’s) to help process your traffic, this is not a super-computer (for Processing) as a “Grid” is usually called.
So that got me thinking, how hard would it be to do it with Relio ?
Apparently, not hard at all .. we already have most of the tools fabricated at the H-Sphere end, just need to invest into the rest of the hardware.
The solution is to use a NAS/NFS load balanced solution, all the data resides on the NAS, and the servers are then load balanced in the front, you can have as many web and mail servers as one needs for processing power (of traffic), should one server go down, the others keep the sites up, since the data also does not reside on the servers, it doesn’t really matter.
Here is a schematic of how it works for H-Sphere currently.
This system allows the Host to add more slave servers as it’s clients needs arise .. so should a site grow exponentially .. one just adds more slave servers, isn’t that the promise of GRID ? unlimited growth with no disturbance to the site ?
BUT, I see how this system could be ever better ..
1 – Add NAS Redundancy, everything is fine and redundant, but should the NAS fail, your whole network is down, one should have a second NAS on a real (or near) time sync, so should one go down, the other keeps the whole setup up.
2 – Make it VPS centric .. if one could define VPS’s as the mailservers and webservers for one user, then as the user grows, one could simply replicate THAT vps into any additional slave server (with a bit of development I am sure) .. the flaw I see is, if in order for ONE user to grow, I need to replicate a whole server, then all the other users on that server are getting a free ride ..
There is another solution, which is to move the growing user to it’s own webserver/mailserver and replicate those as needed, thats a bit more expensive, but it’s a solution neither the less.
My perfect scenario.
I’d love to see us be able to deploy a VPS as a shared account, basically, the user resides on it’s own VPS, but manages his account from within H-Sphere, just like a shared account would, no need for a second CP or additional software, and if we could make all the services for that account to be distributed (1 VPS for mail, 1 for web, 1 for databases) .. then one would replicate those vps’s for load balancing, and then increase copies of those vps’s as growth demanded.
I am sure with time and development, H-Sphere will do just that, or close, for now, I am pricing to try and deploy the existing load balanced system, can I cal it a “GRID” ? .. not sure, but it’s all about marketing.
On a side note: This whole boils down to money .. One needs to be able to charge clients for additional resources, how are people offering 1TB of traffic and hundreds of GB’s of storage for $20 is mind boggling .. it’s not even the matter of “can you do it” .. I’m sure with lots of volume, you can, but why ?, why would I want to make 100K profit on a 10Million Turnover ? call me greedy then, but I want to make 100K profit, on a 500K turnover .. otherwise, I am in jeopardy of running a business with very limited capital, and one slip, and it’s Chapter 11 time.
Update: Ok, I just learned that NAS can do fail-over .. do thats one strike off the wish-list