To Grid Or Not To Grid?

dbgimp writes "In my job at a (large) investment bank I am constantly being pushed to use grid technology. I have many problems with this (not least that our data center is at best 100 Mb/s and our software is actually more data than computation heavy). A typical batch job takes 10-30 minutes consisting of around 10,000 trades. I would far rather spend the time and money on multi-core machines and optimizing the software than on the latest fad technology. I am interested to hear from other people in a similar position and, in particular, why or why not they chose grid software over improving the existing code to leverage better processor technology, and which grid software they chose to use and why. Or, conversely, why they chose not to use grid software."

Comments

Grid vs cluster

[TeknoHog]

Make sure you know the difference between grid technology and clustering. Basically, grid is much more complicated but more flexible; the name means you can connect something to a grid to get computing power, just like you can connect to the power grid to get electricity. It looks like you're thinking of clustering instead, which is easier to deploy and in many ways closer to a multiproc machine

i have a similar problem with virtualization

[kpharmer]

My management is similarly obsessed with virtualization: they want to lower admin costs, lower lab costs, etc through this simple technology.

So, rather than move everything over to lpars I took a simple step - purchased a large virtualization-oriented server highly touted as perfect for this, and moved over a single app, with the goal of putting two apps on this server. Along the way I learned:
    - io virtualization sucks for io-heavy applications
    - the tools to determine how much of the cpu your app is getting at a given moment stink
    - memory virtualization in which you resize application memory is primitive and almost useless
    - there were no guidelines for optimization of the server - just recommendations to try it
        hundreds of different ways and leave it on the best settings
    - basic setup of the machine required wading through tons of jargon that even the os engineers didn't seem to know well
    - out of the box - a single app on the new virtualization server performed more slowly than it did on a free seven year-old server
    - some of the most heavily-advertised virtualization features of the product just don't work
    - virtualization of multiple busy apps onto the same server is mostly a waste of money
    - virtualization of multiple mostly idle app (failover servers, test servers, demo servers, etc) should work very well
    - we spent at least $25k on labor just to create something that was a slam dunk
    - I'm glad that we started with a small prototype - and didn't waste a ton of cash moving everything over immediately the way some management hoped
    - I think in the end we'll get multiple apps working on this box just fine. BUT - we will have spent more money on this scenario than by simply purchasing separate systems. We may recoup a savings if we move enough idle systems onto virtual boxes.

As a result of this experience my team now knows more about virtualization than any other people in the division, we now have a production server supporting it, my management is now cool on this technology, and there is no risk of being forced to migrate critical servers over quickly to the virtual world. I'd call that a success.

I think that you're right - that grid is in a hype cycle right now. So - there are quite a few disappointments to be had along the way to its implementation. For example - if your workload is heavily transactional - you're really not going to get much benefit. In this example oracle supports grids - but it is really more about failover than performance. If you roll your own or use a more sophisticated product you can be safe in assuming that you'll hit unexpected issues, a gap between vendor marketecture & what you really need, and possibly the pain of having a vendor talking directly to your management.

You might want to consider having management fund a small prototype to prove out the benefits. Then let them see that they can achive perhaps better availability but worse performance at a very high cost through this approach.

good luck