Quantifying Availability

J

Jeremy

How can I prove uptime (or quantify downtime) on an ASP.NET 1.1 Web
application (running on an IIS6 Windows Server Standard server)?

What's going on here is that I'm considering the feasability of claiming or
at least establishing some percentage of availability for our production Web
site (99.9%, or 99.99%, or 99.999% "five nines). Of course I'll only
advertise the fact if I can establish it objectively (and it's at least 3
nines :) For those interested, here's a link to an article that describes
what each of those percentages actually means in terms of downtime:
http://searchnetworking.techtarget.com/generic/0,295582,sid7_gci1064318,00.html

So, in IIS6 or perhaps some other feature I could build into our ASP.NET Web
application, is there some way to objectively and accurately measure
downtime or uptime? I'm specifically interested in quantifying the
availability of the ASP.NET Web application.

Suggestions? Thoughts? Perspective?

Thanks!
 
C

Chris Crowe [MVP 2005/2006]

First thoughts - you can not use your ASP.NET application to measure
availability.

You need to test from a number of regions of the world - the reason is that
if you test from say New Zealand and your server is in USA then maybe the
New Zealand gateway is down, maybe the Pacific Gateway is down, maybe the US
gatway is down etc...

is Testing from multiple locations in the world will give you a number of
locations with a number of gateways.

So what are you going to test, a simple ping to the server?, a HTTP Request
checking for a 200 status?, Check for some specific content in the returned
data?

This is all up to you to determine what you consider is up!

If you have 5 sites worldwide, then each site contributes 20% of the total,
now 5 9's means a total downtime of just over 5 minutes.

5 minutes in my mind means - multiple servers, redundant hardware, redundant
links...

--

Cheers

Chris

Chris Crowe [MVP 2005/2006]
http://blog.crowe.co.nz
 
J

Jeremy

Well, not so fast! : )

The people who established this whole "5 nines" availability concept are
from the telephone industry and, for years, they've been measuring the
availability of their various systems (e.g., PBX) and they explicitly
exclude individual telephones and wiring to get TO the PBX board. Yes, those
things are "part of the system" but are explicitly *excluded* from their
availability measures. It would simply be unrealistic to attempt to include
every telephone in the entire world in their availability measures.
Additionally, they are measuring the availabilty of the PBX (or other
switching unit), and *not* measuring the availability of wires getting to it
or of individual telephones at the other end of the wire.

So, I think the same rationalle could be easily generalized over to an
ASP.NET Web site. It can be measured as available - even if some people in
the world cannot get to it.

Put another way, the bank may be open for business, but you cannot get to
the bank because your car has a flat tire. Your flat tire does not in any
way make the bank any less available. It's still open for business.

Any other ideas?






Chris Crowe said:
First thoughts - you can not use your ASP.NET application to measure
availability.

You need to test from a number of regions of the world - the reason is
that if you test from say New Zealand and your server is in USA then maybe
the New Zealand gateway is down, maybe the Pacific Gateway is down, maybe
the US gatway is down etc...

is Testing from multiple locations in the world will give you a number of
locations with a number of gateways.

So what are you going to test, a simple ping to the server?, a HTTP
Request checking for a 200 status?, Check for some specific content in the
returned data?

This is all up to you to determine what you consider is up!

If you have 5 sites worldwide, then each site contributes 20% of the
total, now 5 9's means a total downtime of just over 5 minutes.

5 minutes in my mind means - multiple servers, redundant hardware,
redundant links...

--

Cheers

Chris

Chris Crowe [MVP 2005/2006]
http://blog.crowe.co.nz

------------------------------------------------
Jeremy said:
How can I prove uptime (or quantify downtime) on an ASP.NET 1.1 Web
application (running on an IIS6 Windows Server Standard server)?

What's going on here is that I'm considering the feasability of claiming
or at least establishing some percentage of availability for our
production Web site (99.9%, or 99.99%, or 99.999% "five nines). Of course
I'll only advertise the fact if I can establish it objectively (and it's
at least 3 nines :) For those interested, here's a link to an article
that describes what each of those percentages actually means in terms of
downtime:
http://searchnetworking.techtarget.com/generic/0,295582,sid7_gci1064318,00.html

So, in IIS6 or perhaps some other feature I could build into our ASP.NET
Web application, is there some way to objectively and accurately measure
downtime or uptime? I'm specifically interested in quantifying the
availability of the ASP.NET Web application.

Suggestions? Thoughts? Perspective?

Thanks!
 
K

Ken Schaefer

Hi,

As Chris has mentioned - you need to decide what "available" means. The
server returns a particular page? That certain functionality is still
working? That no requests are timing out (because site or backend is
overloaded). There are a number of 3rd party independant companies that
measure "uptime" (which the major sites use to verify uptime). You might
want to have a look at what those monitoring companies define as "available"

If you want to do the monitoring yourself, you could use something like MOM
(MS Operations Manager) plus the IIS Management Pack to get some idea of
what the site's currently responding to.

But site available is more than just the web components. As you way, you'll
want to exclude the stuff outside your control, but your edge routers, load
balancing equipment etc will need to be monitored (there's no point saying
your website's up for 99.999% of the time if your load balancer is down for
half the day!). All the really big websites have load balancing between
disparate data centers to get around this (e.g. microsoft.com is
geographically load balanced between 3 data centers)

Cheers
Ken

: Well, not so fast! : )
:
: The people who established this whole "5 nines" availability concept are
: from the telephone industry and, for years, they've been measuring the
: availability of their various systems (e.g., PBX) and they explicitly
: exclude individual telephones and wiring to get TO the PBX board. Yes,
those
: things are "part of the system" but are explicitly *excluded* from their
: availability measures. It would simply be unrealistic to attempt to
include
: every telephone in the entire world in their availability measures.
: Additionally, they are measuring the availabilty of the PBX (or other
: switching unit), and *not* measuring the availability of wires getting to
it
: or of individual telephones at the other end of the wire.
:
: So, I think the same rationalle could be easily generalized over to an
: ASP.NET Web site. It can be measured as available - even if some people in
: the world cannot get to it.
:
: Put another way, the bank may be open for business, but you cannot get to
: the bank because your car has a flat tire. Your flat tire does not in any
: way make the bank any less available. It's still open for business.
:
: Any other ideas?
:
:
:
:
:
:
: message : > First thoughts - you can not use your ASP.NET application to measure
: > availability.
: >
: > You need to test from a number of regions of the world - the reason is
: > that if you test from say New Zealand and your server is in USA then
maybe
: > the New Zealand gateway is down, maybe the Pacific Gateway is down,
maybe
: > the US gatway is down etc...
: >
: > is Testing from multiple locations in the world will give you a number
of
: > locations with a number of gateways.
: >
: > So what are you going to test, a simple ping to the server?, a HTTP
: > Request checking for a 200 status?, Check for some specific content in
the
: > returned data?
: >
: > This is all up to you to determine what you consider is up!
: >
: > If you have 5 sites worldwide, then each site contributes 20% of the
: > total, now 5 9's means a total downtime of just over 5 minutes.
: >
: > 5 minutes in my mind means - multiple servers, redundant hardware,
: > redundant links...
: >
: > --
: >
: > Cheers
: >
: > Chris
: >
: > Chris Crowe [MVP 2005/2006]
: > http://blog.crowe.co.nz
: >
: > ------------------------------------------------
: > : >> How can I prove uptime (or quantify downtime) on an ASP.NET 1.1 Web
: >> application (running on an IIS6 Windows Server Standard server)?
: >>
: >> What's going on here is that I'm considering the feasability of
claiming
: >> or at least establishing some percentage of availability for our
: >> production Web site (99.9%, or 99.99%, or 99.999% "five nines). Of
course
: >> I'll only advertise the fact if I can establish it objectively (and
it's
: >> at least 3 nines :) For those interested, here's a link to an article
: >> that describes what each of those percentages actually means in terms
of
: >> downtime:
: >>
http://searchnetworking.techtarget.com/generic/0,295582,sid7_gci1064318,00.html
: >>
: >> So, in IIS6 or perhaps some other feature I could build into our
ASP.NET
: >> Web application, is there some way to objectively and accurately
measure
: >> downtime or uptime? I'm specifically interested in quantifying the
: >> availability of the ASP.NET Web application.
: >>
: >> Suggestions? Thoughts? Perspective?
: >>
: >> Thanks!
: >>
: >
: >
:
:
 
G

Guest

to cut the chase and provide a direct answer , try using bigbrother.com.au a
service that measures site availibility/uptime , you would need to install
the client on your web server.
The BB service will monitor IIS for uptime, and check if the IIS Service is
running, else it would mean the site is down and not working, it would not
account for any additional service checks, and definetely not if the gateways
are up, or bandwidth/network is having issues
 

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