Setting Up My First HA Network
 

Hey Hey!

So I'm super excited because I've been asked to fully design an implement a HA network environment for a new .com start up.

The web site is going to store and stream a lot of media content (common with a lot of web start ups these days) and unfortunately that's where my experience runs a little short.

Configuring load balanced apache web servers and mysql database servers is no big deal, but I'm a little unsure about how to deal with the all of the uploaded media files.

I'm obviously looking to a SAN solution, but I'm a little unsure of how to configure the network. Here's what I have so far (10,000 ft overview):

Firewall -> Web Load Balancers -> Web Node -> Datatbase Load Balancer -> MySQL Database Node

The DB Nodes' data will probably be stored on the SAN.

Now for the media side of it I was thinking about using NFS to mount the centralized media store to all of the web nodes. That way the content urls will work across all of the web nodes, because each node will have the same directory tree /var/www/media which is just an NFS mount from the SAN.

So my real question is - do I really need NFS to achieve this? Or is there another way of sharing partition hard drive space on the SAN with each web node? If I do need to use NFS, then that would mean I'd need an NFS server to make the SAN space accessible by the web nodes (ie the NFS clients).

What is the industry standard approach to doing what I need to do. Obviously in a clustered environment with multiple web nodes where users can upload/stream media - there needs to be a centralized way of making that data accessible - and I'm just a little confused of how it's done.

Any/all help would be greatly appreciated. And wish me/us luck!

Cheers!

NFS or CIFS is fine to me. I haven't had experience with EMC SAN before but have with other various SAN manufacturers. They will usually have the ability to do NFS or CIFS depending if you pay for their licenses. I have used NFS for this type of topology and it works just fine for us. You might need to play with some of the NFS options to suit your environment.

-twantrd

If you you want to use HA-Services. You will be better off with using a SAN.

I think there is no real industry standard when building up web solution stacks.

But you might also want to think about using a clusterfilesystem. Especially when all nodes are attached to a SAN (I suppose you mean FibreChannel/iSCSI when talking about SAN) a clusterfilesystem might become handy. GFS and OCFS2 are the opensource solutions based on linux. I would not suggest OCFS2 for a web server scenario as it is *NOT YET* posix compliant. But GFS could be a nice option. Theoretically a clusterfilesystem should be more determinstic when handling syncronous I/Os and synchronous locking. But this could start a big discussion about pro and cons of NFS vs. Cluster Filesystems or SAN Filesystems.

A nice option when building up scalable infrastructures is moving all the data on the ClusterFilesystem or NFS even the root. Have a look at www.open-sharedroot.org . There you should also find more information about GFS.

Hava fun and good luck.

that kind of environment is i/o intensive. fiber based
storage should the one considered here. but if there's
a budget constraint, checkout:

http://www.openfiler.com/

it is using iSCSi and can easily be integrated to your
current network. unlike if you get a fiber based setup,
you need more h/w (ie switch, cabling + training on how
to manage it).

good luck.