Jens Frank wrote:
On Thu, Jan 08, 2004 at 01:52:13PM -0800, Jimmy Wales wrote:
When I asked the world for $20,000, my intention is that this will see us through a pretty steep growth curve for awhile. I'd like for us to setup a system now that's robust and has a very large amount of reserve capacity, so that as far as we can manage, the site will be highly responsive to users for some time to come *even in a case where we have had bad hardware luck*.
If two squids are good enough and we can survive on one, then I want three. If 3 webservers are handling the load just fine, and we can survive on 2, then I want 5. If geoffrin dies, I want to have another machine that can take the load without breaking a sweat.
You said something else earlier today, that we shouldn't spend the money just because we have it. Being tight-fisted, I somewhat have a problem with "overdelivery". Redundancy is fine, we need it. Having a spare server on site is probably cheaper than a service contract. But 3? Please, someone covince me that we won't find a better way to spend the money in half a year.
I agree with this wholeheartedly. The same money now used on "useless" redundancy or "growth capacity" will buy 50% more in 6 months.
I am advising everyone in my environment to take always "one step back" in hardware, this will be three steps less in price. Remember that the top of the line at any moment is out of date in two months time anyway, so you can just as well buy 2 months old technology right now.
A similar argument holds for memory capacity. I have often seen that people including myself bought an "extensible" computer, but before you actually want to extend it the parts are no longer available or perform badly in your system. If you're really going to be growing memory to 16GB on a system in the future, buying the whole 16GB at that point may be more reliable and cheaper than going for very special modules right now.
ECC is slower and more expensive, but it will prevent an eventual memory error from propagating into disk files thereby potentially corrupting data. This might be advisable to a project like Wikipedia, but only on database and/or file servers.
The only thing where I have personally seen that "expensive pays" is in SCSI vs. ATA (no experience with SATA): The SCSI protocol is so much smarter that it can be not 2 but 10 times faster than ATA if addressed in parallel by concurrent processes. An ftp server working with ATA that I have used would grind to a standstill whenever a backup was running....
Rob