On Fri, 02 Jan 2004 23:34:14 +0000, Nick Hill wrote:
The probability of many fairly reliable
cheap units with no common point of failure breaking down
simaultaneously is much lower than the probability of a costly reliable
unit failing.
I agree with all you're saying and like the thought of having a global
cluster with arbitration, but i have some doubts:
* What's the minimum hardware capable of running the databases, the
webserver, the cache etc? Is all this possible on a cheap unit while still
being fast? I would expect a RAM requirement of at least 4Gb, but i might
be wrong. This would certainly increase once more languages start to grow,
so it might be necessary to have separate machines for separate languages.
* With the number of nodes increasing, replication traffic might be fairly
high (imagine mass undoing somebody's changes replicated to ten machines)
* encryption of replication traffic will drain the cpu, even a simple scp
does this- imagine the same for ten streams
If no single machine is critical and machines are
widely separated, we
would not even need to worry whether the machines are equipped with UPS
or redundant supplies.
If the switchover is quick, this would be perfect- no need for separate
backups and so on.
To get an idea of the hardware requirements it would be nice if somebody
could install all of wikipedia on a cheap box and do some load testing on
it ( if possible with replication).
Gabriel Wicke