Jens Frank wrote:
I took the number "90%" as an example. You
can make it 99% if you like,
No, I don't like to "make it" any number at all. I prefer to base
my opinions on observations from real, running systems. In my
experience, load balancers (just like any Internet router) have near
0% downtime, at most one tenth of the web server applications
involved, especially since the latter tend to be in constant
development. If you can report differing experience, I would listen
to your arguments. But if all you can produce is various guesses in
the 90-99 % range, this becomes pointless. Did you ever buy a Cisco
router that had 99% availability?
I just want to point out that availability will not
increase.
I understand that this is what you want, but I still think you are
wrong.
Just to tease everybody, here is the corresponding table for
http://susning.nu/Sverige (a 44 kbyte page):
Week Beginning Downtime Slowness Avg access time
-------- ----------- -------- -------- ---------------
2003-w44 27 Oct 2003 1 % 1 % 0.66 seconds
2003-w43 20 Oct 2003 1 % 0 % 0.31
2003-w42 13 Oct 2003 1 % 2 % 0.73
2003-w41 6 Oct 2003 2 % 2 % 0.66
2003-w40 29 Sep 2003 0 % 1 % 0.32
2003-w39 22 Sep 2003 0 % 0 % 0.25
2003-w38 15 Sep 2003 0 % 15 % 2.24
2003-w37 8 Sep 2003 0 % 84 % 9.72 (oops!)
2003-w36 1 Sep 2003 0 % 2 % 0.50
2003-w35 25 Aug 2003 0 % 3 % 1.19
2003-w34 18 Aug 2003 0 % 2 % 0.60
2003-w33 11 Aug 2003 0 % 4 % 0.75
2003-w32 4 Aug 2003 0 % 1 % 0.26
2003-w31 28 Jul 2003 0 % 0 % 0.63
2003-w30 21 Jul 2001 0 % 5 % 0.92
Once again, these are my observations, not neutral facts. If you have
observations that differ significantly from these, please tell me.
--
Lars Aronsson (lars(a)aronsson.se)
Aronsson Datateknik -
http://aronsson.se/