Need a good hardware cluster solution

Hi everyone,

The company that I work for is wanting to move to a Windows 2003 Server and
Exchange 2003 clustered environment.  I know that Windows 2003 (Standard)
will do a "Network Load Balancing" and the Enterprise Edition will do both
"Network Load Balancing" and "High Availability" clustering but not BOTH.
If you want to do BOTH "Network Load Balancing" and "High Availability" you
need a third party solution.  That's what I'm looking for, anyone have any
ideas?  Also, any white papers on Windows and Exchange clustering would be
great too.  Thanks for any input.


Clayton


0
none89 (807)
12/16/2004 6:10:54 PM
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check out f5.com specifically their Big-IP solutions.

"Clayton Sutton" wrote:

> Hi everyone,
> 
> The company that I work for is wanting to move to a Windows 2003 Server and
> Exchange 2003 clustered environment.  I know that Windows 2003 (Standard)
> will do a "Network Load Balancing" and the Enterprise Edition will do both
> "Network Load Balancing" and "High Availability" clustering but not BOTH.
> If you want to do BOTH "Network Load Balancing" and "High Availability" you
> need a third party solution.  That's what I'm looking for, anyone have any
> ideas?  Also, any white papers on Windows and Exchange clustering would be
> great too.  Thanks for any input.
> 
> 
> Clayton
> 
> 
> 
0
12/16/2004 7:07:03 PM
Hi,

You don't need a third-party solution to use NLB and server clusters.  For 
example, you can use NLB for front-end Exchange servers (which can run the 
Standard or Enterprise Edition of Exchange) and you can cluster back-end 
Exchange servers (running the Enterprise Edition of Exchange) using the 
Windows Cluster Service found in Windows 2000 Advanced Server, Windows 2000 
Datacenter Server, Windows Server 2003 Enterprise Edition or Windows Server 
2003 Datacenter Edition.

Information on planning, deploying and managing Exchange 2003 clusters can 
be found at:

http://www.microsoft.com/technet/prodtechnol/Exchange/guides/PlanE2k3MsgSys/a3a16698-3caa-4c84-bdc4-0526059ab0b6.mspx

http://www.microsoft.com/technet/prodtechnol/exchange/2003/library/highavailgde.mspx

http://www.microsoft.com/technet/prodtechnol/exchange/2003/library/febetop.mspx

http://www.microsoft.com/technet/prodtechnol/exchange/guides/Ex2k3DepGuide/cc8effcb-7567-4d30-801f-f80129069c56.mspx

http://www.microsoft.com/technet/prodtechnol/exchange/guides/E2k3AdminGuide/47c09fa5-09cc-4fe6-a748-d45f0d3b5ded.mspx

http://www.microsoft.com/technet/prodtechnol/windowsserver2003/technologies/clustering/scenep2.mspx

Hope this helps.

-- 
Scott Schnoll
This posting is provided "AS IS" with no warranties, and confers no
rights. Please do not send email directly to this alias. This alias is for 
newsgroup
purposes only.


"Bryan E Fairchild" <Bryan.Fairchild@ITSchematics.com> wrote in message 
news:C1B03025-7FA8-4D15-84B3-86F163D37A73@microsoft.com...
> check out f5.com specifically their Big-IP solutions.
>
> "Clayton Sutton" wrote:
>
>> Hi everyone,
>>
>> The company that I work for is wanting to move to a Windows 2003 Server 
>> and
>> Exchange 2003 clustered environment.  I know that Windows 2003 (Standard)
>> will do a "Network Load Balancing" and the Enterprise Edition will do 
>> both
>> "Network Load Balancing" and "High Availability" clustering but not BOTH.
>> If you want to do BOTH "Network Load Balancing" and "High Availability" 
>> you
>> need a third party solution.  That's what I'm looking for, anyone have 
>> any
>> ideas?  Also, any white papers on Windows and Exchange clustering would 
>> be
>> great too.  Thanks for any input.
>>
>>
>> Clayton
>>
>>
>> 


0
scschnol (128)
12/16/2004 7:50:49 PM
Yea, but the front end servers would not be "High Availability".  And the
back end servers would not have NLB-ing.  Your solution does assume that a
Microsoft/software solution is the "RIGHT" solution.  I'm looking to see if
there is a hardware solution that will do "BOTH" ("High Availability" and
Load Balencing).  Just doing my homework right now so I don't look dumb when
going into my meeting with my boss next week.


Clayton



"Scott Schnoll [MSFT]" <scschnol@online.microsoft.com> wrote in message
news:er0eFi64EHA.924@TK2MSFTNGP14.phx.gbl...
> Hi,
>
> You don't need a third-party solution to use NLB and server clusters.  For
> example, you can use NLB for front-end Exchange servers (which can run the
> Standard or Enterprise Edition of Exchange) and you can cluster back-end
> Exchange servers (running the Enterprise Edition of Exchange) using the
> Windows Cluster Service found in Windows 2000 Advanced Server, Windows
2000
> Datacenter Server, Windows Server 2003 Enterprise Edition or Windows
Server
> 2003 Datacenter Edition.
>
> Information on planning, deploying and managing Exchange 2003 clusters can
> be found at:
>
>
http://www.microsoft.com/technet/prodtechnol/Exchange/guides/PlanE2k3MsgSys/a3a16698-3caa-4c84-bdc4-0526059ab0b6.mspx
>
>
http://www.microsoft.com/technet/prodtechnol/exchange/2003/library/highavailgde.mspx
>
>
http://www.microsoft.com/technet/prodtechnol/exchange/2003/library/febetop.mspx
>
>
http://www.microsoft.com/technet/prodtechnol/exchange/guides/Ex2k3DepGuide/cc8effcb-7567-4d30-801f-f80129069c56.mspx
>
>
http://www.microsoft.com/technet/prodtechnol/exchange/guides/E2k3AdminGuide/47c09fa5-09cc-4fe6-a748-d45f0d3b5ded.mspx
>
>
http://www.microsoft.com/technet/prodtechnol/windowsserver2003/technologies/clustering/scenep2.mspx
>
> Hope this helps.
>
> -- 
> Scott Schnoll
> This posting is provided "AS IS" with no warranties, and confers no
> rights. Please do not send email directly to this alias. This alias is for
> newsgroup
> purposes only.
>
>
> "Bryan E Fairchild" <Bryan.Fairchild@ITSchematics.com> wrote in message
> news:C1B03025-7FA8-4D15-84B3-86F163D37A73@microsoft.com...
> > check out f5.com specifically their Big-IP solutions.
> >
> > "Clayton Sutton" wrote:
> >
> >> Hi everyone,
> >>
> >> The company that I work for is wanting to move to a Windows 2003 Server
> >> and
> >> Exchange 2003 clustered environment.  I know that Windows 2003
(Standard)
> >> will do a "Network Load Balancing" and the Enterprise Edition will do
> >> both
> >> "Network Load Balancing" and "High Availability" clustering but not
BOTH.
> >> If you want to do BOTH "Network Load Balancing" and "High Availability"
> >> you
> >> need a third party solution.  That's what I'm looking for, anyone have
> >> any
> >> ideas?  Also, any white papers on Windows and Exchange clustering would
> >> be
> >> great too.  Thanks for any input.
> >>
> >>
> >> Clayton
> >>
> >>
> >>
>
>


0
none89 (807)
12/20/2004 5:03:12 AM
Papers on clustering Exchange 2003
www.microsoft.com/exchange/library  (High Availability Guide link here plus
a myriad of other papers)
http://www.microsoft.com/technet/prodtechnol/exchange/2003/library/highavailgde.mspx
=
As for a clustered solution, there are some "cluster in a box" products.
Compaq put one out a few years ago and it worked pretty well.  HP seems to
have continued this.
http://h18004.www1.hp.com/solutions/enterprise/highavailability/microsoft/index.html

Stratus makes servers designed for high-availability.  Literally, you can
yank a processor out of the box and it will keep on humming (not
recommended).  http://www.stratus.com/

HA does not always mean a cluster investment...most of the time, but not
always.  As for load balancing...realistically, if you cluster, you want to
look at an active-active-passive solution...and that is some $$.

Many companies would like five 9's...but when they see the price behind it,
it is pricey up-front.  I have researched five 9's solutions for several of
my past employers as well as the cost of downtime.  Most of the smaller
firms (1000 or less employees) could tolerate some unexpected downtime.
Realistically, with the Compaq hardware I had, there were very few hardware
problems and most of those were self-induced (letting the server room get
over 95 degress (long long story).  Honestly, there were more problems with
people sending 100MB attachments (long story, but it had to be allowed) and
not understanding why it did not get there in 15 seconds like a small 1k
message did.

Bob

"Clayton Sutton" <none@none.com> wrote in message
news:uWg8yo54EHA.1448@TK2MSFTNGP10.phx.gbl...
> Hi everyone,
>
> The company that I work for is wanting to move to a Windows 2003 Server
and
> Exchange 2003 clustered environment.  I know that Windows 2003 (Standard)
> will do a "Network Load Balancing" and the Enterprise Edition will do both
> "Network Load Balancing" and "High Availability" clustering but not BOTH.
> If you want to do BOTH "Network Load Balancing" and "High Availability"
you
> need a third party solution.  That's what I'm looking for, anyone have any
> ideas?  Also, any white papers on Windows and Exchange clustering would be
> great too.  Thanks for any input.
>
>
> Clayton
>
>


0
BobChristian (293)
12/20/2004 5:21:22 AM
"Clayton Sutton" <none@none.com> wrote in message 
news:k2txd.7104862$6p.1117777@news.easynews.com...
> Yea, but the front end servers would not be "High Availability".

Why not?  One server goes down, another is able to take the load. No 
downtime for users.

> And the
> back end servers would not have NLB-ing.

Right. So what you might want to do is look at your business requirements. 
If you require two BE servers, then use a three node cluster with two active 
instances.

> Just doing my homework right now so I don't look dumb when
> going into my meeting with my boss next week.

Part of doing your home work is to understand the business needs and the 
scaling of your solution. I don't think your current thoughts of using 3rd 
party tools will necessarily meet your requirements, especially when it 
comes to support.

So, with that said, why do you think you need both NLB _and_ server 
clustering? 


0
russ4657 (20)
12/20/2004 10:18:10 PM
Well, while I admit I don't know a lot about clustering I thought that if I
used NLB and didn't get "High Availability" (failover).  I thought it just
did "Load Balancing" so if one server went down the you were down.  Then
what's the difference between NLB and "High Availability"?  Why can you use
Windows 2003 Standard for one and you "HAVE" to have Enterprise + for the
other?

> So, with that said, why do you think you need both NLB _and_ server
> clustering?

Isn't NLB also clustering?

Just trying to get my arms around these concepts, thanks for all your input.


Clayton


"Russ Kaufmann [MCT]" <russ@exchangemct.nospam.com> wrote in message
news:eSVtGGu5EHA.2180@TK2MSFTNGP10.phx.gbl...
> "Clayton Sutton" <none@none.com> wrote in message
> news:k2txd.7104862$6p.1117777@news.easynews.com...
> > Yea, but the front end servers would not be "High Availability".
>
> Why not?  One server goes down, another is able to take the load. No
> downtime for users.
>
> > And the
> > back end servers would not have NLB-ing.
>
> Right. So what you might want to do is look at your business requirements.
> If you require two BE servers, then use a three node cluster with two
active
> instances.
>
> > Just doing my homework right now so I don't look dumb when
> > going into my meeting with my boss next week.
>
> Part of doing your home work is to understand the business needs and the
> scaling of your solution. I don't think your current thoughts of using 3rd
> party tools will necessarily meet your requirements, especially when it
> comes to support.
>
> So, with that said, why do you think you need both NLB _and_ server
> clustering?
>
>


0
none89 (807)
12/20/2004 11:16:08 PM
"Clayton Sutton" <none@none.com> wrote in message 
news:Oh$3Hmu5EHA.1204@TK2MSFTNGP10.phx.gbl...
> Well, while I admit I don't know a lot about clustering I thought that if 
> I
> used NLB and didn't get "High Availability" (failover).  I thought it just
> did "Load Balancing" so if one server went down the you were down.  Then
> what's the difference between NLB and "High Availability"?  Why can you 
> use
> Windows 2003 Standard for one and you "HAVE" to have Enterprise + for the
> other?

High availability is a term that is often confusing for many people. 
Basically, a high availability solution is continuously available despite 
the failure of individual components and even the failure of complete 
systems. NLB Clustering and Server Clustering both provide high 
availability.

NLB provides high availability in that with an NLB cluster, if a node fails, 
surviving nodes take on the load of the failed node. NLB is available on all 
Windows Server 2003 platforms.

Server clustering also provides high availability in that if a node fails, 
the application/processes will fail over to a surviving node. Server 
clustering requires Enterprise Editions of software. 


0
russ4657 (20)
12/21/2004 5:39:12 PM
"Russ Kaufmann [MCT]" <russ@exchangemct.nospam.com> wrote:

>"Clayton Sutton" <none@none.com> wrote in message 
>news:Oh$3Hmu5EHA.1204@TK2MSFTNGP10.phx.gbl...
>> Well, while I admit I don't know a lot about clustering I thought that if 
>> I
>> used NLB and didn't get "High Availability" (failover).  I thought it just
>> did "Load Balancing" so if one server went down the you were down.  Then
>> what's the difference between NLB and "High Availability"?  Why can you 
>> use
>> Windows 2003 Standard for one and you "HAVE" to have Enterprise + for the
>> other?
>
>High availability is a term that is often confusing for many people. 
>Basically, a high availability solution is continuously available despite 
>the failure of individual components and even the failure of complete 
>systems. NLB Clustering and Server Clustering both provide high 
>availability.

And just to show how varible that definition may be, "continuously
available" refers to "non-stop computing" and MS clusters certainly
aren't that.

Specialized hardware is needed to survive failures of "individual
components" (disk controllers, motherboards, CPUs, etc.). Think of
machines like Stratus and hardware schemes like Marathon Technologies.
This type of hardware is "fault tolerant", not "fault resistant"
(which is what MS clusters are). Fault tolerant hardware "fails out" a
component. MS clusters "fail over". That's a big difference if you
really need continuity of service.

MS clusters have a single point of failure: the share-nothing disks.
Lose one of those and you might as well be running on a single
machine.

The "continuously available" falls apart when it comes to the time it
takes to "fail over" a node of a MS cluster.


-- 
Rich Matheisen
MCSE+I, Exchange MVP
MS Exchange FAQ at http://www.swinc.com/resource/exch_faq.htm
0
richnews (7316)
12/22/2004 1:59:33 AM
Thanks Rich!

That's the answer to my original post!  I was looking for hardware solutions
that will do a better job then a Windows solution.  Providing both a "Load
Balancing" AND "Continuously Available", "Fault Tolerant" solution!

Clayton



"Rich Matheisen [MVP]" <richnews@rmcons.com.NOSPAM.COM> wrote in message
news:npkhs0tjnnk2iarqrdj9amd18a932r21nv@4ax.com...
> "Russ Kaufmann [MCT]" <russ@exchangemct.nospam.com> wrote:
>
> >"Clayton Sutton" <none@none.com> wrote in message
> >news:Oh$3Hmu5EHA.1204@TK2MSFTNGP10.phx.gbl...
> >> Well, while I admit I don't know a lot about clustering I thought that
if
> >> I
> >> used NLB and didn't get "High Availability" (failover).  I thought it
just
> >> did "Load Balancing" so if one server went down the you were down.
Then
> >> what's the difference between NLB and "High Availability"?  Why can you
> >> use
> >> Windows 2003 Standard for one and you "HAVE" to have Enterprise + for
the
> >> other?
> >
> >High availability is a term that is often confusing for many people.
> >Basically, a high availability solution is continuously available despite
> >the failure of individual components and even the failure of complete
> >systems. NLB Clustering and Server Clustering both provide high
> >availability.
>
> And just to show how varible that definition may be, "continuously
> available" refers to "non-stop computing" and MS clusters certainly
> aren't that.
>
> Specialized hardware is needed to survive failures of "individual
> components" (disk controllers, motherboards, CPUs, etc.). Think of
> machines like Stratus and hardware schemes like Marathon Technologies.
> This type of hardware is "fault tolerant", not "fault resistant"
> (which is what MS clusters are). Fault tolerant hardware "fails out" a
> component. MS clusters "fail over". That's a big difference if you
> really need continuity of service.
>
> MS clusters have a single point of failure: the share-nothing disks.
> Lose one of those and you might as well be running on a single
> machine.
>
> The "continuously available" falls apart when it comes to the time it
> takes to "fail over" a node of a MS cluster.
>
>
> -- 
> Rich Matheisen
> MCSE+I, Exchange MVP
> MS Exchange FAQ at http://www.swinc.com/resource/exch_faq.htm


0
none89 (807)
12/22/2004 3:49:51 AM
I believe 'continuously available' is Russ' definition (after all, they were 
his words <g>).  We do not consider clustering to be a continuously 
available solution (or what might be described as a fault tolerant 
solution).  Clustering provides high availability, which is a level of 
availability approaching 100%.

Both NLB and the Windows Cluster Service provide high availbility.  If you 
build fault tolerance into your NLB/server cluster design, you can achieve 
very high uptime (99.99% or more).
-- 
Scott Schnoll
This posting is provided "AS IS" with no warranties, and confers no
rights. Please do not send email directly to this alias. This alias is for 
newsgroup
purposes only.


"Rich Matheisen [MVP]" <richnews@rmcons.com.NOSPAM.COM> wrote in message 
news:npkhs0tjnnk2iarqrdj9amd18a932r21nv@4ax.com...
> "Russ Kaufmann [MCT]" <russ@exchangemct.nospam.com> wrote:
>
>>"Clayton Sutton" <none@none.com> wrote in message
>>news:Oh$3Hmu5EHA.1204@TK2MSFTNGP10.phx.gbl...
>>> Well, while I admit I don't know a lot about clustering I thought that 
>>> if
>>> I
>>> used NLB and didn't get "High Availability" (failover).  I thought it 
>>> just
>>> did "Load Balancing" so if one server went down the you were down.  Then
>>> what's the difference between NLB and "High Availability"?  Why can you
>>> use
>>> Windows 2003 Standard for one and you "HAVE" to have Enterprise + for 
>>> the
>>> other?
>>
>>High availability is a term that is often confusing for many people.
>>Basically, a high availability solution is continuously available despite
>>the failure of individual components and even the failure of complete
>>systems. NLB Clustering and Server Clustering both provide high
>>availability.
>
> And just to show how varible that definition may be, "continuously
> available" refers to "non-stop computing" and MS clusters certainly
> aren't that.
>
> Specialized hardware is needed to survive failures of "individual
> components" (disk controllers, motherboards, CPUs, etc.). Think of
> machines like Stratus and hardware schemes like Marathon Technologies.
> This type of hardware is "fault tolerant", not "fault resistant"
> (which is what MS clusters are). Fault tolerant hardware "fails out" a
> component. MS clusters "fail over". That's a big difference if you
> really need continuity of service.
>
> MS clusters have a single point of failure: the share-nothing disks.
> Lose one of those and you might as well be running on a single
> machine.
>
> The "continuously available" falls apart when it comes to the time it
> takes to "fail over" a node of a MS cluster.
>
>
> -- 
> Rich Matheisen
> MCSE+I, Exchange MVP
> MS Exchange FAQ at http://www.swinc.com/resource/exch_faq.htm 


0
scschnol (128)
12/22/2004 4:23:15 PM
Thanks for the input Scott,

What do you mean by:  "If you build fault tolerance into your NLB/server
cluster design"?  Using a product like... (what?)


Clayton




"Scott Schnoll [MSFT]" <scschnol@online.microsoft.com> wrote in message
news:uKm2LKE6EHA.2540@TK2MSFTNGP09.phx.gbl...
> I believe 'continuously available' is Russ' definition (after all, they
were
> his words <g>).  We do not consider clustering to be a continuously
> available solution (or what might be described as a fault tolerant
> solution).  Clustering provides high availability, which is a level of
> availability approaching 100%.
>
> Both NLB and the Windows Cluster Service provide high availbility.  If you
> build fault tolerance into your NLB/server cluster design, you can achieve
> very high uptime (99.99% or more).
> -- 
> Scott Schnoll
> This posting is provided "AS IS" with no warranties, and confers no
> rights. Please do not send email directly to this alias. This alias is for
> newsgroup
> purposes only.
>
>
> "Rich Matheisen [MVP]" <richnews@rmcons.com.NOSPAM.COM> wrote in message
> news:npkhs0tjnnk2iarqrdj9amd18a932r21nv@4ax.com...
> > "Russ Kaufmann [MCT]" <russ@exchangemct.nospam.com> wrote:
> >
> >>"Clayton Sutton" <none@none.com> wrote in message
> >>news:Oh$3Hmu5EHA.1204@TK2MSFTNGP10.phx.gbl...
> >>> Well, while I admit I don't know a lot about clustering I thought that
> >>> if
> >>> I
> >>> used NLB and didn't get "High Availability" (failover).  I thought it
> >>> just
> >>> did "Load Balancing" so if one server went down the you were down.
Then
> >>> what's the difference between NLB and "High Availability"?  Why can
you
> >>> use
> >>> Windows 2003 Standard for one and you "HAVE" to have Enterprise + for
> >>> the
> >>> other?
> >>
> >>High availability is a term that is often confusing for many people.
> >>Basically, a high availability solution is continuously available
despite
> >>the failure of individual components and even the failure of complete
> >>systems. NLB Clustering and Server Clustering both provide high
> >>availability.
> >
> > And just to show how varible that definition may be, "continuously
> > available" refers to "non-stop computing" and MS clusters certainly
> > aren't that.
> >
> > Specialized hardware is needed to survive failures of "individual
> > components" (disk controllers, motherboards, CPUs, etc.). Think of
> > machines like Stratus and hardware schemes like Marathon Technologies.
> > This type of hardware is "fault tolerant", not "fault resistant"
> > (which is what MS clusters are). Fault tolerant hardware "fails out" a
> > component. MS clusters "fail over". That's a big difference if you
> > really need continuity of service.
> >
> > MS clusters have a single point of failure: the share-nothing disks.
> > Lose one of those and you might as well be running on a single
> > machine.
> >
> > The "continuously available" falls apart when it comes to the time it
> > takes to "fail over" a node of a MS cluster.
> >
> >
> > -- 
> > Rich Matheisen
> > MCSE+I, Exchange MVP
> > MS Exchange FAQ at http://www.swinc.com/resource/exch_faq.htm
>
>


0
none89 (807)
12/22/2004 5:55:00 PM
"Rich Matheisen [MVP]" <richnews@rmcons.com.NOSPAM.COM> wrote in message 
news:npkhs0tjnnk2iarqrdj9amd18a932r21nv@4ax.com...
>>High availability is a term that is often confusing for many people.
>>Basically, a high availability solution is continuously available despite
>>the failure of individual components and even the failure of complete
>>systems. NLB Clustering and Server Clustering both provide high
>>availability.
>
> And just to show how varible that definition may be, "continuously
> available" refers to "non-stop computing" and MS clusters certainly
> aren't that.

Agreed, but I was just providing a "generic" definition here.



0
russ4657 (20)
12/22/2004 7:14:41 PM
"Scott Schnoll [MSFT]" <scschnol@online.microsoft.com> wrote in message 
news:uKm2LKE6EHA.2540@TK2MSFTNGP09.phx.gbl...
>I believe 'continuously available' is Russ' definition (after all, they 
>were his words <g>).

:)  Yes, it was a "generic" definition to help Clayton understand better 
what is meant by HA in context with NLB and Server Clustering.


0
russ4657 (20)
12/22/2004 7:16:13 PM
You may want to clarify that then, as the definition is not accurate for NLB 
or server clusters.
-- 
Scott Schnoll
This posting is provided "AS IS" with no warranties, and confers no
rights. Please do not send email directly to this alias. This alias is for 
newsgroup
purposes only.


"Russ Kaufmann [MCT]" <russ@exchangemct.nospam.com> wrote in message 
news:eAJPvpF6EHA.936@TK2MSFTNGP12.phx.gbl...
> "Scott Schnoll [MSFT]" <scschnol@online.microsoft.com> wrote in message 
> news:uKm2LKE6EHA.2540@TK2MSFTNGP09.phx.gbl...
>>I believe 'continuously available' is Russ' definition (after all, they 
>>were his words <g>).
>
> :)  Yes, it was a "generic" definition to help Clayton understand better 
> what is meant by HA in context with NLB and Server Clustering.
>
> 


0
scschnol (128)
12/22/2004 7:18:19 PM
"Clayton Sutton" <none@none.com> wrote in message 
news:%23W6i97E6EHA.1120@TK2MSFTNGP11.phx.gbl...
> Thanks for the input Scott,
>
> What do you mean by:  "If you build fault tolerance into your NLB/server
> cluster design"?  Using a product like... (what?)

As Rich pointed out, we can do many things to improve uptime through fault 
tolerance. For example, if your servers have dual power supplies, RAID 
configurations for hard drives, dual connections to dual Fiber switches, 
mirrored RAM, and so on and so on. You can then combine the fault tolerance 
within a server to the next level by having multiple servers in either an 
NLB cluster or a server cluster. Which technology you choose will most 
likely be dependent on the application requirements.

From my years of working with lock step products like Marathon, I really 
haven't seen much improvement in uptime of an application over a Microsoft 
cluster. When you start getting to 99.99%, you can rest pretty easy. 


0
russ4657 (20)
12/22/2004 7:21:21 PM
"Scott Schnoll [MSFT]" <scschnol@online.microsoft.com> wrote in message 
news:eMzgCsF6EHA.2512@TK2MSFTNGP09.phx.gbl...
> You may want to clarify that then, as the definition is not accurate for 
> NLB or server clusters.

I think I just did, but thanks, I will expand here. Just to be clear, this 
is not a Microsoft take on the world of HA.

Clayton, "continuous availability" is not necessarily what I meant when it 
comes to the truest definition of the term, but it is a term that I have 
found resonates with many people and they begin to understand what HA means.

Don't worry that Microsoft uses terms a little differently, but if you 
decide to do some googling, you will find the terms are often used 
interchangeably by many major players in the industry. For example, one 
definition states:

"In information technology, high availability refers to a system or 
component that is continuously operational for a desirably long length of 
time. Availability can be measured relative to "100% operational" or "never 
failing." A widely-held but difficult-to-achieve standard of availability 
for a system or product is known as "five 9s" (99.999 percent) 
availability."

Source: 
http://searchcio.techtarget.com/sDefinition/0,,sid19_gci761219,00.html

Obviously, "never failing" just isn't possible over extremely long periods. 
We all need to understand that HA includes not just the design of the 
hardware/software solution, but it also includes the backup/restore 
solution, and it includes failover processing. Some experts will also 
contend that a true HA environment includes a well documented development, 
test, and production migration process with in-depth documentation. There is 
much to achieving HA, however, it simply comes down to application 
availability through processes, software, and hardware implementations.

If you use NLB to provide application availability to your users over the 
Internet for your web based app, then that is fantastic. It helps keep the 
application available to your users. The same can be said for server 
clustering, however, you need to take into account the non-availability 
during the actual failover of your application. Sometimes, it is a matter of 
seconds, in other cases it can be several minutes. In all cases, a 
clustering solution will significantly drive down non-availability and 
increase the uptime of your application as run on your servers.
Many experts state that, for any application or system to be highly 
available, the parts need to be designed around availability and the 
individual parts need to be tested before being put into production. As an 
example, if you are using 3rd party products with your Exchange environment 
that have not been properly tested, you may find that they are a weak link 
that results in loss of availability. Implementing an Exchange server 
cluster will not necessarily result in HA.


0
russ4657 (20)
12/22/2004 7:47:00 PM
It's not a product.  It's all in your design.  Things like RAID arrays, SMP 
processors, ECC memory, redundant power supplies, redundant networks, etc. 
You can have an HA solution with NLB and server clusters.  As an example, 
have a look at the Exchange Server 2003 High Availability Guide at 
http://www.microsoft.com/technet/prodtechnol/exchange/2003/library/highavailgde.mspx.
-- 
Scott Schnoll
This posting is provided "AS IS" with no warranties, and confers no
rights. Please do not send email directly to this alias. This alias is for 
newsgroup
purposes only.


"Clayton Sutton" <none@none.com> wrote in message 
news:%23W6i97E6EHA.1120@TK2MSFTNGP11.phx.gbl...
> Thanks for the input Scott,
>
> What do you mean by:  "If you build fault tolerance into your NLB/server
> cluster design"?  Using a product like... (what?)
>
>
> Clayton
>
>
>
>
> "Scott Schnoll [MSFT]" <scschnol@online.microsoft.com> wrote in message
> news:uKm2LKE6EHA.2540@TK2MSFTNGP09.phx.gbl...
>> I believe 'continuously available' is Russ' definition (after all, they
> were
>> his words <g>).  We do not consider clustering to be a continuously
>> available solution (or what might be described as a fault tolerant
>> solution).  Clustering provides high availability, which is a level of
>> availability approaching 100%.
>>
>> Both NLB and the Windows Cluster Service provide high availbility.  If 
>> you
>> build fault tolerance into your NLB/server cluster design, you can 
>> achieve
>> very high uptime (99.99% or more).
>> -- 
>> Scott Schnoll
>> This posting is provided "AS IS" with no warranties, and confers no
>> rights. Please do not send email directly to this alias. This alias is 
>> for
>> newsgroup
>> purposes only.
>>
>>
>> "Rich Matheisen [MVP]" <richnews@rmcons.com.NOSPAM.COM> wrote in message
>> news:npkhs0tjnnk2iarqrdj9amd18a932r21nv@4ax.com...
>> > "Russ Kaufmann [MCT]" <russ@exchangemct.nospam.com> wrote:
>> >
>> >>"Clayton Sutton" <none@none.com> wrote in message
>> >>news:Oh$3Hmu5EHA.1204@TK2MSFTNGP10.phx.gbl...
>> >>> Well, while I admit I don't know a lot about clustering I thought 
>> >>> that
>> >>> if
>> >>> I
>> >>> used NLB and didn't get "High Availability" (failover).  I thought it
>> >>> just
>> >>> did "Load Balancing" so if one server went down the you were down.
> Then
>> >>> what's the difference between NLB and "High Availability"?  Why can
> you
>> >>> use
>> >>> Windows 2003 Standard for one and you "HAVE" to have Enterprise + for
>> >>> the
>> >>> other?
>> >>
>> >>High availability is a term that is often confusing for many people.
>> >>Basically, a high availability solution is continuously available
> despite
>> >>the failure of individual components and even the failure of complete
>> >>systems. NLB Clustering and Server Clustering both provide high
>> >>availability.
>> >
>> > And just to show how varible that definition may be, "continuously
>> > available" refers to "non-stop computing" and MS clusters certainly
>> > aren't that.
>> >
>> > Specialized hardware is needed to survive failures of "individual
>> > components" (disk controllers, motherboards, CPUs, etc.). Think of
>> > machines like Stratus and hardware schemes like Marathon Technologies.
>> > This type of hardware is "fault tolerant", not "fault resistant"
>> > (which is what MS clusters are). Fault tolerant hardware "fails out" a
>> > component. MS clusters "fail over". That's a big difference if you
>> > really need continuity of service.
>> >
>> > MS clusters have a single point of failure: the share-nothing disks.
>> > Lose one of those and you might as well be running on a single
>> > machine.
>> >
>> > The "continuously available" falls apart when it comes to the time it
>> > takes to "fail over" a node of a MS cluster.
>> >
>> >
>> > -- 
>> > Rich Matheisen
>> > MCSE+I, Exchange MVP
>> > MS Exchange FAQ at http://www.swinc.com/resource/exch_faq.htm
>>
>>
>
> 


0
scschnol (128)
12/22/2004 7:51:48 PM
Comments inline...
-- 
Scott Schnoll
This posting is provided "AS IS" with no warranties, and confers no
rights. Please do not send email directly to this alias. This alias is for 
newsgroup
purposes only.


"Russ Kaufmann [MCT]" <russ@exchangemct.nospam.com> wrote in message 
news:ObYu66F6EHA.3124@TK2MSFTNGP11.phx.gbl...
> "Scott Schnoll [MSFT]" <scschnol@online.microsoft.com> wrote in message 
> news:eMzgCsF6EHA.2512@TK2MSFTNGP09.phx.gbl...
>> You may want to clarify that then, as the definition is not accurate for 
>> NLB or server clusters.
>
> I think I just did, but thanks, I will expand here. Just to be clear, this 
> is not a Microsoft take on the world of HA.
>
> Clayton, "continuous availability" is not necessarily what I meant when it 
> comes to the truest definition of the term, but it is a term that I have 
> found resonates with many people and they begin to understand what HA 
> means.

Please don't confuse these terms.  We go to great lengths in our content and 
documentation to clearly state what you get from our products and 
technologies.  We do not have any products or technologies that provide 
continuous availability.  Whether it resonates or not, if you are using the 
term 'continuous availbility' then you are actually creating confusion for 
Microsoft customers interested in high availbility.

> Don't worry that Microsoft uses terms a little differently, but if you 
> decide to do some googling, you will find the terms are often used 
> interchangeably by many major players in the industry. For example, one 
> definition states:
>
> "In information technology, high availability refers to a system or 
> component that is continuously operational for a desirably long length of 
> time. Availability can be measured relative to "100% operational" or 
> "never failing." A widely-held but difficult-to-achieve standard of 
> availability for a system or product is known as "five 9s" (99.999 
> percent) availability."
>
> Source: 
> http://searchcio.techtarget.com/sDefinition/0,,sid19_gci761219,00.html

I personally disagree with this definition of high availability and not just 
because it different from Microsoft's definition.  Continuously available is 
the term for a fault tolerant system.  We are talking about high 
availability.  These are two different concepts which are often confused and 
co-mingled, as is the case in this thread.

> Obviously, "never failing" just isn't possible over extremely long 
> periods. We all need to understand that HA includes not just the design of 
> the hardware/software solution, but it also includes the backup/restore 
> solution, and it includes failover processing. Some experts will also 
> contend that a true HA environment includes a well documented development, 
> test, and production migration process with in-depth documentation. There 
> is much to achieving HA, however, it simply comes down to application 
> availability through processes, software, and hardware implementations.
> If you use NLB to provide application availability to your users over the 
> Internet for your web based app, then that is fantastic. It helps keep the 
> application available to your users. The same can be said for server 
> clustering, however, you need to take into account the non-availability 
> during the actual failover of your application. Sometimes, it is a matter 
> of seconds, in other cases it can be several minutes. In all cases, a 
> clustering solution will significantly drive down non-availability and 
> increase the uptime of your application as run on your servers.
> Many experts state that, for any application or system to be highly 
> available, the parts need to be designed around availability and the 
> individual parts need to be tested before being put into production. As an 
> example, if you are using 3rd party products with your Exchange 
> environment that have not been properly tested, you may find that they are 
> a weak link that results in loss of availability. Implementing an Exchange 
> server cluster will not necessarily result in HA.

When the messaging infrastructure is implemented properly and in accordance 
with Microsoft best practices, an Exchange cluster can most certainly result 
in HA. 


0
scschnol (128)
12/22/2004 8:01:18 PM
I really didn't want to get involved, but please read Microsoft's
Achieving High Availability with Exchange Server at Microsoft at
http://download.microsoft.com/download/a/5/8/a58cbb94-06c6-4deb-8ca7-4eae5227f7ca/ExchangeHighAvailabilityTSB.doc

Great stuff. The article is about how Microsoft takes its five 9's 
seriously. It talks about the No Excuse approach. HA should be way more then 
Clustering or NLB, as the article states.

Just my two cents - not directed at Scott or Russ or Clayton, but the topic 
in general.

Cheers,

Rod

MVP - Windows Server - Clustering
http://www.nw-america.com - Clustering
http://msmvps.com/clustering - Blog

"Scott Schnoll [MSFT]" <scschnol@online.microsoft.com> wrote in message
news:e$BLBEG6EHA.208@TK2MSFTNGP12.phx.gbl...
> Comments inline...
> -- 
> Scott Schnoll
> This posting is provided "AS IS" with no warranties, and confers no
> rights. Please do not send email directly to this alias. This alias is for
> newsgroup
> purposes only.
>
>
> "Russ Kaufmann [MCT]" <russ@exchangemct.nospam.com> wrote in message
> news:ObYu66F6EHA.3124@TK2MSFTNGP11.phx.gbl...
>> "Scott Schnoll [MSFT]" <scschnol@online.microsoft.com> wrote in message
>> news:eMzgCsF6EHA.2512@TK2MSFTNGP09.phx.gbl...
>>> You may want to clarify that then, as the definition is not accurate for
>>> NLB or server clusters.
>>
>> I think I just did, but thanks, I will expand here. Just to be clear,
>> this is not a Microsoft take on the world of HA.
>>
>> Clayton, "continuous availability" is not necessarily what I meant when
>> it comes to the truest definition of the term, but it is a term that I
>> have found resonates with many people and they begin to understand what
>> HA means.
>
> Please don't confuse these terms.  We go to great lengths in our content
> and documentation to clearly state what you get from our products and
> technologies.  We do not have any products or technologies that provide
> continuous availability.  Whether it resonates or not, if you are using
> the term 'continuous availbility' then you are actually creating confusion
> for Microsoft customers interested in high availbility.
>
>> Don't worry that Microsoft uses terms a little differently, but if you
>> decide to do some googling, you will find the terms are often used
>> interchangeably by many major players in the industry. For example, one
>> definition states:
>>
>> "In information technology, high availability refers to a system or
>> component that is continuously operational for a desirably long length of
>> time. Availability can be measured relative to "100% operational" or
>> "never failing." A widely-held but difficult-to-achieve standard of
>> availability for a system or product is known as "five 9s" (99.999
>> percent) availability."
>>
>> Source:
>> http://searchcio.techtarget.com/sDefinition/0,,sid19_gci761219,00.html
>
> I personally disagree with this definition of high availability and not
> just because it different from Microsoft's definition.  Continuously
> available is the term for a fault tolerant system.  We are talking about
> high availability.  These are two different concepts which are often
> confused and co-mingled, as is the case in this thread.
>
>> Obviously, "never failing" just isn't possible over extremely long
>> periods. We all need to understand that HA includes not just the design
>> of the hardware/software solution, but it also includes the
>> backup/restore solution, and it includes failover processing. Some
>> experts will also contend that a true HA environment includes a well
>> documented development, test, and production migration process with
>> in-depth documentation. There is much to achieving HA, however, it simply
>> comes down to application availability through processes, software, and
>> hardware implementations.
>> If you use NLB to provide application availability to your users over the
>> Internet for your web based app, then that is fantastic. It helps keep
>> the application available to your users. The same can be said for server
>> clustering, however, you need to take into account the non-availability
>> during the actual failover of your application. Sometimes, it is a matter
>> of seconds, in other cases it can be several minutes. In all cases, a
>> clustering solution will significantly drive down non-availability and
>> increase the uptime of your application as run on your servers.
>> Many experts state that, for any application or system to be highly
>> available, the parts need to be designed around availability and the
>> individual parts need to be tested before being put into production. As
>> an example, if you are using 3rd party products with your Exchange
>> environment that have not been properly tested, you may find that they
>> are a weak link that results in loss of availability. Implementing an
>> Exchange server cluster will not necessarily result in HA.
>
> When the messaging infrastructure is implemented properly and in
> accordance with Microsoft best practices, an Exchange cluster can most
> certainly result in HA.
>



0
rod5651 (26)
12/22/2004 8:13:43 PM
"Scott Schnoll [MSFT]" <scschnol@online.microsoft.com> wrote in message 
news:e$BLBEG6EHA.208@TK2MSFTNGP12.phx.gbl...
> "Russ Kaufmann [MCT]" <russ@exchangemct.nospam.com> wrote in message 
> news:ObYu66F6EHA.3124@TK2MSFTNGP11.phx.gbl...
>> Clayton, "continuous availability" is not necessarily what I meant when 
>> it comes to the truest definition of the term, but it is a term that I 
>> have found resonates with many people and they begin to understand what 
>> HA means.
>
> Please don't confuse these terms.  We go to great lengths in our content 
> and documentation to clearly state what you get from our products and 
> technologies.  We do not have any products or technologies that provide 
> continuous availability.

To which I agree and did not state that Microsoft does. However, I did 
provide a very common definition and clarified it is not Microsoft's.

>> "In information technology, high availability refers to a system or 
>> component that is continuously operational for a desirably long length of 
>> time. Availability can be measured relative to "100% operational" or 
>> "never failing." A widely-held but difficult-to-achieve standard of 
>> availability for a system or product is known as "five 9s" (99.999 
>> percent) availability."
>>
>> Source: 
>> http://searchcio.techtarget.com/sDefinition/0,,sid19_gci761219,00.html
>
> I personally disagree with this definition of high availability and not 
> just because it different from Microsoft's definition.  Continuously 
> available is the term for a fault tolerant system.

Continuous availability (CA) is self defining. In a CA solution there is 
zero down time. We all agree with that, right? However, I think everyone 
also agrees that there really is no such thing as a CA solution when it 
comes to extended lengths of time. Since solutions include hardware and 
software and both fail and not all failures can be configured to not result 
in downtime, CA is a dream, but it is a nice goal.

To be clear, Microsoft server clustering results in minimal downtime 
(failover time) and can be used along with other components to achieve an HA 
solution. Microsoft NLB clustering also results in minimal (practically 
zero) downtime. Both are components that can be used as part of an HA 
solution.

Other components, such as hardware, can contain fault tolerant components 
and still be part of an HA solution. Right? If you are trying to say that HA 
can not include fault tolerant components, then we will just have to agree 
to disagree.  HA comes from implementation of well designed processes, 
hardware, and software. You can't achieve HA solutions without properly 
implementing all three. You can disagree with this, but I think I have 
enough support in the industry to back me up here.

> We are talking about high availability.  These are two different concepts 
> which are often confused and co-mingled, as is the case in this thread.

You can disagree all you want. The definition for HA comes from the goal of 
CA. Replace minimal downtime with no downtime, and HA becomes CA. Again, I 
can't stress this enough, CA is not achievable over extended lenghts of 
time. The industry has several overlapping definitions because of the common 
elements between CA and HA solutions. I agree with the ones that states that 
HA includes well designed processes, hardware, and software implementations 
resulting in minimal downtime, thus HA. Continuous availability, as defined, 
just isn't achievable. I use it to help understand what HA is, though, and 
it works for most people.

>> Obviously, "never failing" just isn't possible over extremely long 
>> periods. We all need to understand that HA includes not just the design 
>> of the hardware/software solution, but it also includes the 
>> backup/restore solution, and it includes failover processing. Some 
>> experts will also contend that a true HA environment includes a well 
>> documented development, test, and production migration process with 
>> in-depth documentation. There is much to achieving HA, however, it simply 
>> comes down to application availability through processes, software, and 
>> hardware implementations.
>> If you use NLB to provide application availability to your users over the 
>> Internet for your web based app, then that is fantastic. It helps keep 
>> the application available to your users. The same can be said for server 
>> clustering, however, you need to take into account the non-availability 
>> during the actual failover of your application. Sometimes, it is a matter 
>> of seconds, in other cases it can be several minutes. In all cases, a 
>> clustering solution will significantly drive down non-availability and 
>> increase the uptime of your application as run on your servers.
>> Many experts state that, for any application or system to be highly 
>> available, the parts need to be designed around availability and the 
>> individual parts need to be tested before being put into production. As 
>> an example, if you are using 3rd party products with your Exchange 
>> environment that have not been properly tested, you may find that they 
>> are a weak link that results in loss of availability. Implementing an 
>> Exchange server cluster will not necessarily result in HA.
>
> When the messaging infrastructure is implemented properly and in 
> accordance with Microsoft best practices, an Exchange cluster can most 
> certainly result in HA.

You obviously missed what I said, Scott. I said that if you include 3rd 
party stuff that has not been properly tested or implmented, it may result 
in loss of availability that clustering will not fix.

Can Exchange clustering result in HA?  Absolutely. Can clustering Exchange 
servers that include untested 3rd party code fix the problems? Absolutely 
not. Clustering alone does not result in HA solutions. 


0
russ4657 (20)
12/22/2004 8:59:09 PM
"Rodney R. Fournier [MVP]" <rod@die.spam.die.nw-america.com> wrote in 
message news:ehX09KG6EHA.2804@TK2MSFTNGP15.phx.gbl...
>I really didn't want to get involved, but please read Microsoft's
> Achieving High Availability with Exchange Server at Microsoft at
> http://download.microsoft.com/download/a/5/8/a58cbb94-06c6-4deb-8ca7-4eae5227f7ca/ExchangeHighAvailabilityTSB.doc
>
> Great stuff. The article is about how Microsoft takes its five 9's 
> seriously. It talks about the No Excuse approach. HA should be way more 
> then Clustering or NLB, as the article states.

I absolutely agree with you. HA takes way more than just implementing server 
clustering or NLB clustering. However, they can be components of an HA 
solution. 


0
russ4657 (20)
12/22/2004 9:00:28 PM
Comments inline...
-- 
Scott Schnoll
This posting is provided "AS IS" with no warranties, and confers no
rights. Please do not send email directly to this alias. This alias is for 
newsgroup
purposes only.


"Russ Kaufmann [MCT]" <russ@exchangemct.nospam.com> wrote in message 
news:eqSPNjG6EHA.2196@TK2MSFTNGP11.phx.gbl...
> "Scott Schnoll [MSFT]" <scschnol@online.microsoft.com> wrote in message 
> news:e$BLBEG6EHA.208@TK2MSFTNGP12.phx.gbl...
>> "Russ Kaufmann [MCT]" <russ@exchangemct.nospam.com> wrote in message 
>> news:ObYu66F6EHA.3124@TK2MSFTNGP11.phx.gbl...
>>> Clayton, "continuous availability" is not necessarily what I meant when 
>>> it comes to the truest definition of the term, but it is a term that I 
>>> have found resonates with many people and they begin to understand what 
>>> HA means.
>>
>> Please don't confuse these terms.  We go to great lengths in our content 
>> and documentation to clearly state what you get from our products and 
>> technologies.  We do not have any products or technologies that provide 
>> continuous availability.
>
> To which I agree and did not state that Microsoft does. However, I did 
> provide a very common definition and clarified it is not Microsoft's.

OK.

>>> "In information technology, high availability refers to a system or 
>>> component that is continuously operational for a desirably long length 
>>> of time. Availability can be measured relative to "100% operational" or 
>>> "never failing." A widely-held but difficult-to-achieve standard of 
>>> availability for a system or product is known as "five 9s" (99.999 
>>> percent) availability."
>>>
>>> Source: 
>>> http://searchcio.techtarget.com/sDefinition/0,,sid19_gci761219,00.html
>>
>> I personally disagree with this definition of high availability and not 
>> just because it different from Microsoft's definition.  Continuously 
>> available is the term for a fault tolerant system.
>
> Continuous availability (CA) is self defining. In a CA solution there is 
> zero down time. We all agree with that, right? However, I think everyone 
> also agrees that there really is no such thing as a CA solution when it 
> comes to extended lengths of time. Since solutions include hardware and 
> software and both fail and not all failures can be configured to not 
> result in downtime, CA is a dream, but it is a nice goal.

I don't know if I agree with that or not.  Define down time.

> To be clear, Microsoft server clustering results in minimal downtime 
> (failover time) and can be used along with other components to achieve an 
> HA solution. Microsoft NLB clustering also results in minimal (practically 
> zero) downtime. Both are components that can be used as part of an HA 
> solution.
>
> Other components, such as hardware, can contain fault tolerant components 
> and still be part of an HA solution. Right? If you are trying to say that 
> HA can not include fault tolerant components, then we will just have to 
> agree to disagree.  HA comes from implementation of well designed 
> processes, hardware, and software. You can't achieve HA solutions without 
> properly implementing all three. You can disagree with this, but I think I 
> have enough support in the industry to back me up here.

HA does not equal FT.  Here are the definitions I use:

Fault tolerance is the ability of a system to continue functioning when part 
of it fails (e.g., experiences a fault). This term is used to describe disk 
subsystems (e.g., RAID), symmetric multiple processors (SMP), redundant 
power supplies (with separate power sources), uninterruptible power 
supplies, redundant network adapters, etc.  Fault tolerance is designed to 
alleviate the problems caused by component failures, power outages, or other 
like occurrences.

High-Availability refers to a system uptime that approaches 100%.  For 
example, an availability level of 99.999%, calculated on a round-the-clock 
basis, would mean that an organization would experience at least five 
minutes of unscheduled downtime per year.  A level of 99.99% translates to 
52 minutes of downtime.  A level of 99.9% translates to 8.7 hours, and a 
level of 99% equals about 3.7 days of downtime per year.

HA systems are often built with a fault tolerance design using fault 
tolerance components.

>> We are talking about high availability.  These are two different concepts 
>> which are often confused and co-mingled, as is the case in this thread.
>
> You can disagree all you want. The definition for HA comes from the goal 
> of CA. Replace minimal downtime with no downtime, and HA becomes CA. 
> Again, I can't stress this enough, CA is not achievable over extended 
> lenghts of time. The industry has several overlapping definitions because 
> of the common elements between CA and HA solutions. I agree with the ones 
> that states that HA includes well designed processes, hardware, and 
> software implementations resulting in minimal downtime, thus HA. 
> Continuous availability, as defined, just isn't achievable. I use it to 
> help understand what HA is, though, and it works for most people.

That is all great information, but it has nothing whatsoever to do with this 
thread.  Let's get back to Clayton's original question if we can:

"The company that I work for is wanting to move to a Windows 2003 Server and
Exchange 2003 clustered environment.  I know that Windows 2003 (Standard)
will do a "Network Load Balancing" and the Enterprise Edition will do both
"Network Load Balancing" and "High Availability" clustering but not BOTH.
If you want to do BOTH "Network Load Balancing" and "High Availability" you
need a third party solution.  That's what I'm looking for, anyone have any
ideas?  Also, any white papers on Windows and Exchange clustering would be
great too.  Thanks for any input."

Clayton is asking about NLB and HA for his Exchange cluster, and he is 
asking it in a Microsoft newsgroup (albeit an unmanaged newsgroup).  However 
industry pundits define CA, HA or FT, the question here is specific to 
Windows 2003 and Exchange 2003, and what can be achieved.  I'm not against 
dreaming about 100% or CA or whatever you want to call it, but I do get 
concerned when I see a customer being confused by misleading terms and 
incomplete information.

>>> Obviously, "never failing" just isn't possible over extremely long 
>>> periods. We all need to understand that HA includes not just the design 
>>> of the hardware/software solution, but it also includes the 
>>> backup/restore solution, and it includes failover processing. Some 
>>> experts will also contend that a true HA environment includes a well 
>>> documented development, test, and production migration process with 
>>> in-depth documentation. There is much to achieving HA, however, it 
>>> simply comes down to application availability through processes, 
>>> software, and hardware implementations.
>>> If you use NLB to provide application availability to your users over 
>>> the Internet for your web based app, then that is fantastic. It helps 
>>> keep the application available to your users. The same can be said for 
>>> server clustering, however, you need to take into account the 
>>> non-availability during the actual failover of your application. 
>>> Sometimes, it is a matter of seconds, in other cases it can be several 
>>> minutes. In all cases, a clustering solution will significantly drive 
>>> down non-availability and increase the uptime of your application as run 
>>> on your servers.
>>> Many experts state that, for any application or system to be highly 
>>> available, the parts need to be designed around availability and the 
>>> individual parts need to be tested before being put into production. As 
>>> an example, if you are using 3rd party products with your Exchange 
>>> environment that have not been properly tested, you may find that they 
>>> are a weak link that results in loss of availability. Implementing an 
>>> Exchange server cluster will not necessarily result in HA.
>>
>> When the messaging infrastructure is implemented properly and in 
>> accordance with Microsoft best practices, an Exchange cluster can most 
>> certainly result in HA.
>
> You obviously missed what I said, Scott. I said that if you include 3rd 
> party stuff that has not been properly tested or implmented, it may result 
> in loss of availability that clustering will not fix.

No, I read that part.  Don't let me absence of a comment lead you to believe 
I missed information.  What you have said is generically true about every 
computer, clustered or not.

> Can Exchange clustering result in HA?  Absolutely. Can clustering Exchange 
> servers that include untested 3rd party code fix the problems? Absolutely 
> not. Clustering alone does not result in HA solutions.

I don't think anyone ever said anything contrary to these statements. 


0
scschnol (128)
12/22/2004 9:23:19 PM
"Scott Schnoll [MSFT]" <scschnol@online.microsoft.com> wrote in message 
news:uajB2xG6EHA.2788@TK2MSFTNGP15.phx.gbl...
>> Continuous availability (CA) is self defining. In a CA solution there is 
>> zero down time. We all agree with that, right? However, I think everyone 
>> also agrees that there really is no such thing as a CA solution when it 
>> comes to extended lengths of time. Since solutions include hardware and 
>> software and both fail and not all failures can be configured to not 
>> result in downtime, CA is a dream, but it is a nice goal.
>
> I don't know if I agree with that or not.  Define down time.

Time when the application is not available. This can be a tricky definition, 
though. For example, if the Exchange VS is failing over, it isn't available 
at that time. However, one of the features taht I love with Exchange Server 
2003 and Outlook 2003 is the cached mode so that the users do not experience 
a loss of service in that they can respond to messages and write new 
messages while this failover is happening. So, I don't know how to define 
that time. <G>

> HA does not equal FT.  Here are the definitions I use:
>
> Fault tolerance is the ability of a system to continue functioning when 
> part of it fails (e.g., experiences a fault). This term is used to 
> describe disk subsystems (e.g., RAID), symmetric multiple processors 
> (SMP), redundant power supplies (with separate power sources), 
> uninterruptible power supplies, redundant network adapters, etc.  Fault 
> tolerance is designed to alleviate the problems caused by component 
> failures, power outages, or other like occurrences.

But yet, isn't FT (for hardware like the above) part of an HA solution?  I 
believe it is. Without it being part of the solution, the overall solution 
would have greater non-availability.

> High-Availability refers to a system uptime that approaches 100%.  For 
> example, an availability level of 99.999%, calculated on a round-the-clock 
> basis, would mean that an organization would experience at least five 
> minutes of unscheduled downtime per year.  A level of 99.99% translates to 
> 52 minutes of downtime.  A level of 99.9% translates to 8.7 hours, and a 
> level of 99% equals about 3.7 days of downtime per year.

Agreed. The magic 100% comes under CA. Thus why they are both used in the 
same discussions most of the time.

> HA systems are often built with a fault tolerance design using fault 
> tolerance components.

Absolutely, and I believe I had said that. Thus why I don't equate FT with 
CA only.

> "The company that I work for is wanting to move to a Windows 2003 Server 
> and
> Exchange 2003 clustered environment.  I know that Windows 2003 (Standard)
> will do a "Network Load Balancing" and the Enterprise Edition will do both
> "Network Load Balancing" and "High Availability" clustering but not BOTH.
> If you want to do BOTH "Network Load Balancing" and "High Availability" 
> you
> need a third party solution.  That's what I'm looking for, anyone have any
> ideas?  Also, any white papers on Windows and Exchange clustering would be
> great too.  Thanks for any input."
>
> Clayton is asking about NLB and HA for his Exchange cluster, and he is 
> asking it in a Microsoft newsgroup (albeit an unmanaged newsgroup). 
> However industry pundits define CA, HA or FT, the question here is 
> specific to Windows 2003 and Exchange 2003, and what can be achieved.  I'm 
> not against dreaming about 100% or CA or whatever you want to call it, but 
> I do get concerned when I see a customer being confused by misleading 
> terms and incomplete information.

I see your point, but I think this thread has helped make that clear not 
just to Clayton, but to everyone else. This has been a very helpful thread.



0
russ4657 (20)
12/22/2004 9:37:28 PM
Then there are such things as user-impacting downtime and non-user-impacting
downtime.

I had a manager that said to me once... zero impact on the user is our goal.
If it's down and it does not impact the user or generate a helpdesk ticket,
that does not impact the user.  We must strive for the same thing internally
because the monitoring system is not a user and it will rat us out without a
guilty feeling.

Bob

"Russ Kaufmann [MCT]" <russ@exchangemct.nospam.com> wrote in message
news:uvO$o4G6EHA.4072@TK2MSFTNGP10.phx.gbl...
> "Scott Schnoll [MSFT]" <scschnol@online.microsoft.com> wrote in message
> news:uajB2xG6EHA.2788@TK2MSFTNGP15.phx.gbl...
> >> Continuous availability (CA) is self defining. In a CA solution there
is
> >> zero down time. We all agree with that, right? However, I think
everyone
> >> also agrees that there really is no such thing as a CA solution when it
> >> comes to extended lengths of time. Since solutions include hardware and
> >> software and both fail and not all failures can be configured to not
> >> result in downtime, CA is a dream, but it is a nice goal.
> >
> > I don't know if I agree with that or not.  Define down time.
>
> Time when the application is not available. This can be a tricky
definition,
> though. For example, if the Exchange VS is failing over, it isn't
available
> at that time. However, one of the features taht I love with Exchange
Server
> 2003 and Outlook 2003 is the cached mode so that the users do not
experience
> a loss of service in that they can respond to messages and write new
> messages while this failover is happening. So, I don't know how to define
> that time. <G>
>
> > HA does not equal FT.  Here are the definitions I use:
> >
> > Fault tolerance is the ability of a system to continue functioning when
> > part of it fails (e.g., experiences a fault). This term is used to
> > describe disk subsystems (e.g., RAID), symmetric multiple processors
> > (SMP), redundant power supplies (with separate power sources),
> > uninterruptible power supplies, redundant network adapters, etc.  Fault
> > tolerance is designed to alleviate the problems caused by component
> > failures, power outages, or other like occurrences.
>
> But yet, isn't FT (for hardware like the above) part of an HA solution?  I
> believe it is. Without it being part of the solution, the overall solution
> would have greater non-availability.
>
> > High-Availability refers to a system uptime that approaches 100%.  For
> > example, an availability level of 99.999%, calculated on a
round-the-clock
> > basis, would mean that an organization would experience at least five
> > minutes of unscheduled downtime per year.  A level of 99.99% translates
to
> > 52 minutes of downtime.  A level of 99.9% translates to 8.7 hours, and a
> > level of 99% equals about 3.7 days of downtime per year.
>
> Agreed. The magic 100% comes under CA. Thus why they are both used in the
> same discussions most of the time.
>
> > HA systems are often built with a fault tolerance design using fault
> > tolerance components.
>
> Absolutely, and I believe I had said that. Thus why I don't equate FT with
> CA only.
>
> > "The company that I work for is wanting to move to a Windows 2003 Server
> > and
> > Exchange 2003 clustered environment.  I know that Windows 2003
(Standard)
> > will do a "Network Load Balancing" and the Enterprise Edition will do
both
> > "Network Load Balancing" and "High Availability" clustering but not
BOTH.
> > If you want to do BOTH "Network Load Balancing" and "High Availability"
> > you
> > need a third party solution.  That's what I'm looking for, anyone have
any
> > ideas?  Also, any white papers on Windows and Exchange clustering would
be
> > great too.  Thanks for any input."
> >
> > Clayton is asking about NLB and HA for his Exchange cluster, and he is
> > asking it in a Microsoft newsgroup (albeit an unmanaged newsgroup).
> > However industry pundits define CA, HA or FT, the question here is
> > specific to Windows 2003 and Exchange 2003, and what can be achieved.
I'm
> > not against dreaming about 100% or CA or whatever you want to call it,
but
> > I do get concerned when I see a customer being confused by misleading
> > terms and incomplete information.
>
> I see your point, but I think this thread has helped make that clear not
> just to Clayton, but to everyone else. This has been a very helpful
thread.
>
>
>


0
BobChristian (293)
12/23/2004 12:19:24 AM
"Bob Christian" <BobChristian@removethis.gmail.com> wrote in message 
news:uSwzvUI6EHA.3756@TK2MSFTNGP14.phx.gbl...
> Then there are such things as user-impacting downtime and 
> non-user-impacting
> downtime.
>
> I had a manager that said to me once... zero impact on the user is our 
> goal.
> If it's down and it does not impact the user or generate a helpdesk 
> ticket,
> that does not impact the user.  We must strive for the same thing 
> internally
> because the monitoring system is not a user and it will rat us out without 
> a
> guilty feeling.

Absolutely. The goal is to be able to provide the application despite the 
failure of a components or a complete system.

Where I work, we have such incredible high levels of automation, a server 
cluster failover will actually generate several different tickets. A ticket 
is generated for the failover of every resource, so even if you manually 
move the resources to another node, management is made aware of the change. 
You can't hide downtime from the automated tools, even if it doesn't impact 
the user community. 


0
russ4657 (20)
12/23/2004 4:33:55 PM
Inline...
-- 
Scott Schnoll
This posting is provided "AS IS" with no warranties, and confers no
rights. Please do not send email directly to this alias. This alias is for 
newsgroup
purposes only.


"Russ Kaufmann [MCT]" <russ@exchangemct.nospam.com> wrote in message 
news:%23z56tzQ6EHA.2196@TK2MSFTNGP11.phx.gbl...
> "Bob Christian" <BobChristian@removethis.gmail.com> wrote in message 
> news:uSwzvUI6EHA.3756@TK2MSFTNGP14.phx.gbl...
>> Then there are such things as user-impacting downtime and 
>> non-user-impacting
>> downtime.
>>
>> I had a manager that said to me once... zero impact on the user is our 
>> goal.
>> If it's down and it does not impact the user or generate a helpdesk 
>> ticket,
>> that does not impact the user.  We must strive for the same thing 
>> internally
>> because the monitoring system is not a user and it will rat us out 
>> without a
>> guilty feeling.
>
> Absolutely. The goal is to be able to provide the application despite the 
> failure of a components or a complete system.

Right, so what is the application in this case?  Before you answer, its 
hypothetical.  :-)  This is the primary challenge we have with Exchange 
because we really serve two distinct groups of users: (1) IT Pros, the folks 
who manage servers, such as AD and Exchange; and (2) Information workers, 
such as those user Outlook or ActiveSync or some other Exchange client. 
This is why each organization must determine for itself what downtime means 
and how to measure and combat it.

> Where I work, we have such incredible high levels of automation, a server 
> cluster failover will actually generate several different tickets. A 
> ticket is generated for the failover of every resource, so even if you 
> manually move the resources to another node, management is made aware of 
> the change. You can't hide downtime from the automated tools, even if it 
> doesn't impact the user community.

Yes, you can.  :-)  Configure the tools with exclusions so that certain 
failures don't trigger tickets or alerts.  I have yet to see a monitoring 
solution that doesn't provide some sort of exclusion features so that you 
can "hide" downtime from the tool. 


0
scschnol (128)
12/23/2004 4:42:08 PM
"Scott Schnoll [MSFT]" <scschnol@online.microsoft.com> wrote in message 
news:uTNOZ5Q6EHA.2452@TK2MSFTNGP14.phx.gbl...
>> Absolutely. The goal is to be able to provide the application despite the 
>> failure of a components or a complete system.
>
> Right, so what is the application in this case?  Before you answer, its 
> hypothetical.  :-)  This is the primary challenge we have with Exchange 
> because we really serve two distinct groups of users: (1) IT Pros, the 
> folks who manage servers, such as AD and Exchange; and (2) Information 
> workers, such as those user Outlook or ActiveSync or some other Exchange 
> client. This is why each organization must determine for itself what 
> downtime means and how to measure and combat it.

Yep, many different definitions for different users. It really makes uptime 
reporting a nightmare.

>> Where I work, we have such incredible high levels of automation, a server 
>> cluster failover will actually generate several different tickets. A 
>> ticket is generated for the failover of every resource, so even if you 
>> manually move the resources to another node, management is made aware of 
>> the change. You can't hide downtime from the automated tools, even if it 
>> doesn't impact the user community.
>
> Yes, you can.  :-)  Configure the tools with exclusions so that certain 
> failures don't trigger tickets or alerts.  I have yet to see a monitoring 
> solution that doesn't provide some sort of exclusion features so that you 
> can "hide" downtime from the tool.

Regrettably, the monitoring tool is managed by a different team (gotta keep 
us honest) and it is a combination of a well known vendor tool and an 
in-house tool. I have been trying to ply the monitoring team with lots of 
beer, but it doesn't work. <G> 


0
russ4657 (20)
12/23/2004 4:54:40 PM
Clayton,

Two possibilities are NSI Doubletake (www.nsisoftweare.com) or
Neverfail group ( www.neverfailgroup.com )

NSI is more of a replication solution

Neverfail is a high availability solution and replication

Depends which one you are looking for and what you want to achieve.
Both are inexpensive, we've purchase Neverfail because we needed the
high availability it provides.

Jo K


Clayton Sutton wrote:
> Hi everyone,
>
> The company that I work for is wanting to move to a Windows 2003
Server and
> Exchange 2003 clustered environment.  I know that Windows 2003
(Standard)
> will do a "Network Load Balancing" and the Enterprise Edition will do
both
> "Network Load Balancing" and "High Availability" clustering but not
BOTH.
> If you want to do BOTH "Network Load Balancing" and "High
Availability" you
> need a third party solution.  That's what I'm looking for, anyone
have any
> ideas?  Also, any white papers on Windows and Exchange clustering
would be
> great too.  Thanks for any input.
> 
> 
> Clayton

0
joknash (7)
12/23/2004 5:38:34 PM
First off, let me say that I have ENJOYED this thread!  You guy's input
(your give and take back and fourth) has been VERY in-lighting AND helpful!
ALL of you guys are the best!!!


In trying to get my arms around the subject at had, can you guys clear up
the difference between an "NLB" cluster and a "Server" cluster.  I know that
"NLB" stands for "Network Load Balancing" and I know what that is.  However,
in a "Server" cluster if one server goes down another one takes over.
Right?

Does an "NLB" cluster do the same?  What if I had a four node "NLB" cluster
and I lost a node?  Would the whole cluster be down?

I am trying to understand the technical difference (other then "Load
Balancing") between an "NLB" cluster and a "Server" cluster.

By the way, I am reading as many white papers as I can, I just haven't
gotten to that part yet.  I am buried in "White Papers" right now (if you
know what I mean) :).

Thanks again for all of your help.


Clayton



"Russ Kaufmann [MCT]" <russ@exchangemct.nospam.com> wrote in message
news:u7hbT$Q6EHA.2592@TK2MSFTNGP09.phx.gbl...
> "Scott Schnoll [MSFT]" <scschnol@online.microsoft.com> wrote in message
> news:uTNOZ5Q6EHA.2452@TK2MSFTNGP14.phx.gbl...
> >> Absolutely. The goal is to be able to provide the application despite
the
> >> failure of a components or a complete system.
> >
> > Right, so what is the application in this case?  Before you answer, its
> > hypothetical.  :-)  This is the primary challenge we have with Exchange
> > because we really serve two distinct groups of users: (1) IT Pros, the
> > folks who manage servers, such as AD and Exchange; and (2) Information
> > workers, such as those user Outlook or ActiveSync or some other Exchange
> > client. This is why each organization must determine for itself what
> > downtime means and how to measure and combat it.
>
> Yep, many different definitions for different users. It really makes
uptime
> reporting a nightmare.
>
> >> Where I work, we have such incredible high levels of automation, a
server
> >> cluster failover will actually generate several different tickets. A
> >> ticket is generated for the failover of every resource, so even if you
> >> manually move the resources to another node, management is made aware
of
> >> the change. You can't hide downtime from the automated tools, even if
it
> >> doesn't impact the user community.
> >
> > Yes, you can.  :-)  Configure the tools with exclusions so that certain
> > failures don't trigger tickets or alerts.  I have yet to see a
monitoring
> > solution that doesn't provide some sort of exclusion features so that
you
> > can "hide" downtime from the tool.
>
> Regrettably, the monitoring tool is managed by a different team (gotta
keep
> us honest) and it is a combination of a well known vendor tool and an
> in-house tool. I have been trying to ply the monitoring team with lots of
> beer, but it doesn't work. <G>
>
>


0
none89 (807)
12/23/2004 9:39:45 PM
Cool Jo K,

Thanks for that info.  I don't know what direction our project is going to
take just yet so I am just doing some homework to come up to speed on both
hardware AND software solutions.  Our IT dept. will be meeting with
managment after the holidays to talk about an HA solution.


Clayton



"Jo K" <joknash@hotmail.com> wrote in message
news:1103823514.113933.94430@c13g2000cwb.googlegroups.com...
> Clayton,
>
> Two possibilities are NSI Doubletake (www.nsisoftweare.com) or
> Neverfail group ( www.neverfailgroup.com )
>
> NSI is more of a replication solution
>
> Neverfail is a high availability solution and replication
>
> Depends which one you are looking for and what you want to achieve.
> Both are inexpensive, we've purchase Neverfail because we needed the
> high availability it provides.
>
> Jo K
>
>
> Clayton Sutton wrote:
> > Hi everyone,
> >
> > The company that I work for is wanting to move to a Windows 2003
> Server and
> > Exchange 2003 clustered environment.  I know that Windows 2003
> (Standard)
> > will do a "Network Load Balancing" and the Enterprise Edition will do
> both
> > "Network Load Balancing" and "High Availability" clustering but not
> BOTH.
> > If you want to do BOTH "Network Load Balancing" and "High
> Availability" you
> > need a third party solution.  That's what I'm looking for, anyone
> have any
> > ideas?  Also, any white papers on Windows and Exchange clustering
> would be
> > great too.  Thanks for any input.
> >
> >
> > Clayton
>


0
none89 (807)
12/23/2004 9:45:00 PM
Thanks Bob, the links are GREAT!


Clayton



"Bob Christian" <BobChristian@removethis.gmail.com> wrote in message
news:eK3egPl5EHA.1596@tk2msftngp13.phx.gbl...
> Papers on clustering Exchange 2003
> www.microsoft.com/exchange/library  (High Availability Guide link here
plus
> a myriad of other papers)
>
http://www.microsoft.com/technet/prodtechnol/exchange/2003/library/highavailgde.mspx
> =
> As for a clustered solution, there are some "cluster in a box" products.
> Compaq put one out a few years ago and it worked pretty well.  HP seems to
> have continued this.
>
http://h18004.www1.hp.com/solutions/enterprise/highavailability/microsoft/index.html
>
> Stratus makes servers designed for high-availability.  Literally, you can
> yank a processor out of the box and it will keep on humming (not
> recommended).  http://www.stratus.com/
>
> HA does not always mean a cluster investment...most of the time, but not
> always.  As for load balancing...realistically, if you cluster, you want
to
> look at an active-active-passive solution...and that is some $$.
>
> Many companies would like five 9's...but when they see the price behind
it,
> it is pricey up-front.  I have researched five 9's solutions for several
of
> my past employers as well as the cost of downtime.  Most of the smaller
> firms (1000 or less employees) could tolerate some unexpected downtime.
> Realistically, with the Compaq hardware I had, there were very few
hardware
> problems and most of those were self-induced (letting the server room get
> over 95 degress (long long story).  Honestly, there were more problems
with
> people sending 100MB attachments (long story, but it had to be allowed)
and
> not understanding why it did not get there in 15 seconds like a small 1k
> message did.
>
> Bob
>
> "Clayton Sutton" <none@none.com> wrote in message
> news:uWg8yo54EHA.1448@TK2MSFTNGP10.phx.gbl...
> > Hi everyone,
> >
> > The company that I work for is wanting to move to a Windows 2003 Server
> and
> > Exchange 2003 clustered environment.  I know that Windows 2003
(Standard)
> > will do a "Network Load Balancing" and the Enterprise Edition will do
both
> > "Network Load Balancing" and "High Availability" clustering but not
BOTH.
> > If you want to do BOTH "Network Load Balancing" and "High Availability"
> you
> > need a third party solution.  That's what I'm looking for, anyone have
any
> > ideas?  Also, any white papers on Windows and Exchange clustering would
be
> > great too.  Thanks for any input.
> >
> >
> > Clayton
> >
> >
>
>


0
none89 (807)
12/23/2004 9:45:47 PM
answers inline...

Cheers,

Rod

MVP - Windows Server - Clustering
http://www.nw-america.com - Clustering
http://msmvps.com/clustering - Blog

"Clayton Sutton" <none@none.com> wrote in message 
news:u$Lt9dT6EHA.3376@TK2MSFTNGP12.phx.gbl...
> First off, let me say that I have ENJOYED this thread!  You guy's input
> (your give and take back and fourth) has been VERY in-lighting AND 
> helpful!
> ALL of you guys are the best!!!
>
>
> In trying to get my arms around the subject at had, can you guys clear up
> the difference between an "NLB" cluster and a "Server" cluster.  I know 
> that
> "NLB" stands for "Network Load Balancing" and I know what that is. 
> However,
> in a "Server" cluster if one server goes down another one takes over.
> Right?
>

NLB is at the network level, NLB is TCP, UDP, IGMP. NLB is sometimes called 
clustering. NLB is mainly for Website or Terminal Services. Server 
Clustering is for application like SQL or Exchange. Server Clustering is 
called clustering.

> Does an "NLB" cluster do the same?  What if I had a four node "NLB" 
> cluster
> and I lost a node?  Would the whole cluster be down?

With a 4 node (you can max out at 32) NLB cluster, if you lose or gain one 
the cluster will converge with the new number and life will move on. You 
will have minor outages during that time, but only for the clients attached 
to the dead server. The whole cluster will not go down, unless you have less 
then 1 node up :)

>
> I am trying to understand the technical difference (other then "Load
> Balancing") between an "NLB" cluster and a "Server" cluster.
>

NLB = IP stuff, Server = Applications. Simple way to think about it.

> By the way, I am reading as many white papers as I can, I just haven't
> gotten to that part yet.  I am buried in "White Papers" right now (if you
> know what I mean) :).

My website has a ton of them on clustering...

>
> Thanks again for all of your help.
>
>
> Clayton
>
>
>
> "Russ Kaufmann [MCT]" <russ@exchangemct.nospam.com> wrote in message
> news:u7hbT$Q6EHA.2592@TK2MSFTNGP09.phx.gbl...
>> "Scott Schnoll [MSFT]" <scschnol@online.microsoft.com> wrote in message
>> news:uTNOZ5Q6EHA.2452@TK2MSFTNGP14.phx.gbl...
>> >> Absolutely. The goal is to be able to provide the application despite
> the
>> >> failure of a components or a complete system.
>> >
>> > Right, so what is the application in this case?  Before you answer, its
>> > hypothetical.  :-)  This is the primary challenge we have with Exchange
>> > because we really serve two distinct groups of users: (1) IT Pros, the
>> > folks who manage servers, such as AD and Exchange; and (2) Information
>> > workers, such as those user Outlook or ActiveSync or some other 
>> > Exchange
>> > client. This is why each organization must determine for itself what
>> > downtime means and how to measure and combat it.
>>
>> Yep, many different definitions for different users. It really makes
> uptime
>> reporting a nightmare.
>>
>> >> Where I work, we have such incredible high levels of automation, a
> server
>> >> cluster failover will actually generate several different tickets. A
>> >> ticket is generated for the failover of every resource, so even if you
>> >> manually move the resources to another node, management is made aware
> of
>> >> the change. You can't hide downtime from the automated tools, even if
> it
>> >> doesn't impact the user community.
>> >
>> > Yes, you can.  :-)  Configure the tools with exclusions so that certain
>> > failures don't trigger tickets or alerts.  I have yet to see a
> monitoring
>> > solution that doesn't provide some sort of exclusion features so that
> you
>> > can "hide" downtime from the tool.
>>
>> Regrettably, the monitoring tool is managed by a different team (gotta
> keep
>> us honest) and it is a combination of a well known vendor tool and an
>> in-house tool. I have been trying to ply the monitoring team with lots of
>> beer, but it doesn't work. <G>
>>
>>
>
> 


0
rod5651 (26)
12/23/2004 10:23:04 PM
"Scott Schnoll [MSFT]" <scschnol@online.microsoft.com> wrote in message
news:uajB2xG6EHA.2788@TK2MSFTNGP15.phx.gbl...
> Comments inline...
> -- 
> Scott Schnoll
> This posting is provided "AS IS" with no warranties, and confers no
> rights. Please do not send email directly to this alias. This alias is for
> newsgroup
> purposes only.
>
>but I do get concerned when I see a customer being confused by misleading
terms and
> incomplete information.

"Misleading" is RIGHT!  That's kinda what started this whole thing.  Too
many people throwing around terms and using them interchangeably.  But
because of EVERYONE here in this thread I now have a MUCH better
understanding of HA, CA, and FT.  If you don't know the lingo, you can read
all the "White Papers" you want and you will still come away with a faulty
understanding of the subject!

Let me say that neather of you guys (Russ or Scott) have been misleading to
me.  Russ's examples have REALLY helped me (a lay person) start to get my
arms around the subject.  Then you Scott have come in behind Russ and REALLY
help me to nail it down!

This has been a VERY COOL exchange of thoughts!

Thank you very much guys.


Calyton


0
none89 (807)
12/24/2004 1:55:22 AM
"Clayton Sutton" <none@none.com> wrote in message 
news:u$Lt9dT6EHA.3376@TK2MSFTNGP12.phx.gbl...
> First off, let me say that I have ENJOYED this thread!  You guy's input
> (your give and take back and fourth) has been VERY in-lighting AND 
> helpful!
> ALL of you guys are the best!!!

I think we all enjoyed it. <G>

> In trying to get my arms around the subject at had, can you guys clear up
> the difference between an "NLB" cluster and a "Server" cluster.  I know 
> that
> "NLB" stands for "Network Load Balancing" and I know what that is. 
> However,
> in a "Server" cluster if one server goes down another one takes over.
> Right?

This link has great info on NLB features that should help you better 
understand what NLB can do for you. Rod mentions Web and Terminal Services 
as two apps that normally use NLB clustering instead of server clustering. 
There are others.
http://support.microsoft.com/default.aspx?scid=http://support.microsoft.com:80/support/kb/articles/q232/1/90.asp&NoWebContent=1

This link will point you to an NLB FAQ. One of the questions in the FAQ is 
just what you are asking.
http://www.microsoft.com/technet/prodtechnol/windowsserver2003/technologies/clustering/nlbfaq.mspx#XSLTfaqSection126124121120120



0
russ4657 (20)
12/29/2004 5:08:22 PM
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