Update - None of this is official yet:
After many hours checking and rechecking my numbers, I've found that my
previous preliminary estimate of $25K to $30K for a quarter 3 budget was a bit
off. The problem was with my estimate of the amount of money we previously
spent per 1000 hits over the last year. I figured *total* previous hits and
then applied that to projected *increases* in hits in the future. Thus my
estimate was too optimistic.
After recalculating for past *increases* in traffic I've found that if our
traffic increases 90.53% over last quarter by the end of this quarter we will
have to buy $29K to $35K dollars worth of new servers to keep up with the
increase (if we don't have any traffic increase, then we won't have to spend a
dime unless a server has to be replaced). This figure includes a Moore's Law
adjustment which assumes we will be able to serve ~17% more hits per new server
dollar over last quarter (I'm still not 100% confident that that is a valid
assumption - any ideas?). The previous $25K to $30K estimate *did not* include
a Moore's Law adjustment.
Other possibilities:
% growth 35.22% 254.90% 20.00% 50.00% 100.00%
$/1000 hits $11,274.81 $81,595.03 $6,402.22 $16,005.54 $32,011.09
Average $13,609.25 $98,489.19 $7,727.79 $19,319.47 $38,638.95
NOTE: The 35.22% figure is the actual growth from Q1 to Q2 and the 254.90%
figure is the actual growth from Q4 2003 to Q1 2004. The average quarter to
quarter growth over the last couple years, however, is about 90%. But who knows
if this quarter will follow that or do something unpredictable like the last
two quarters.
For the grant proposal I projected 90% quarterly compounded hit growth into
2006. The results are a bit shocking due to exponential growth.
Year annual budget
2004 $110K - $132K
2005 $660K - $797K
2006 $4200K - $5078K
This assumes business as usual (meaning we continue to use the same kind of
commodity-grade rack-mount servers and do not have any real time mirrors -
migrating to 'big-iron' servers and making use of a worldwide squid/mirror
system will mitigate for this).
But there are still probably more errors in my estimates and I doubt we can
continue exponential growth for too long into the future (at least not at the
same absurd rate - 30% hit growth compounded quarterly would be much more
manageable but still exponential).
I'll upload my spreadsheet to meta later so that others can check/improve my
analysis.
Off to bed now though.
Daniel Mayer,
Wikimedia CFO
__________________________________
Do you Yahoo!?
New and Improved Yahoo! Mail - 100MB free storage!
http://promotions.yahoo.com/new_mail