Subject | Re: [firebird-support] Down time |
---|---|
Author | Olivier Mascia |
Post date | 2004-07-31T08:56:53Z |
Hello,
Fri, 30 Jul 2004 17:45:33 -0400, "Ann W. Harrison" <aharrison@...> wrote:
AWH> The reason for my question is MySQL's "cluster" support.
AWH> My reading of it is that their "clusters" have nothing to
AWH> do with what used to be called clusters - groups of
AWH> machines that share disk but not memory. The MySQL site
AWH> claims that their clusters give "high availability" aka
AWH> "5 nines". Looking more closely, "5 nines" means 99.999%
AWH> up time. Sounds good. 0.001% of a week is 10 minutes.
You're off by a factor of 100.
1% is 1/100 so 0.001% is 1/100000.
That turns to be 6 seconds a week.
Or 5 min and about 15 seconds per year.
;-)
--
Olivier Mascia
Fri, 30 Jul 2004 17:45:33 -0400, "Ann W. Harrison" <aharrison@...> wrote:
AWH> The reason for my question is MySQL's "cluster" support.
AWH> My reading of it is that their "clusters" have nothing to
AWH> do with what used to be called clusters - groups of
AWH> machines that share disk but not memory. The MySQL site
AWH> claims that their clusters give "high availability" aka
AWH> "5 nines". Looking more closely, "5 nines" means 99.999%
AWH> up time. Sounds good. 0.001% of a week is 10 minutes.
You're off by a factor of 100.
1% is 1/100 so 0.001% is 1/100000.
That turns to be 6 seconds a week.
Or 5 min and about 15 seconds per year.
;-)
--
Olivier Mascia