Active/Active or Active/Passive

Hello,
We are going to design our SQL Server databases on either Active/Active or
Active/Passive of Windows 2003 clusters.
Has any one seen real time risk and their real experiences of using
Active/Active clusters?
Thanks, John
The only real issue is when one node dies and its SQL instance(s)
failover to the other node so a single node has multiple instances
running on it. You just need to make sure each node has enough
resources (CPU and memory primarily and to a lesser extent NIC
throughput and SCSI controller (or SAN HBA) capacity) to support both
instances simultaneously.
It also depends on whether it's acceptable to your business to run both
SQL instances at a degraded performance level until you can get the dead
node back on its feet (assuming the business doesn't want to fork out
the cash to have more CPU & memory in each node in order to adequately
run both instances on one node).
Personally, where I work we run 4 production clusters (each with 2 SQL
instances on it) and an off-site DR cluster (with 2 SQL instances on
it). I can't remember a problem in the last 5 years that we've had on
any instance on our clusters that wouldn't have also happened if we'd
only had a single instance on each cluster (the issue were all OS level
or hardware level issues - to be honest, our stand-alone SQL boxes were
always more stable but obviously didn't have the failover capacity if
something went wrong). However, we tend to run cluster nodes with a
little resource overhead in them in case of a failover.
*mike hodgson*
http://sqlnerd.blogspot.com
John wrote:

>Hello,
>We are going to design our SQL Server databases on either Active/Active or
>Active/Passive of Windows 2003 clusters.
>Has any one seen real time risk and their real experiences of using
>Active/Active clusters?
>Thanks, John
>

Activation procedure design

I've been experimenting with Service Broker and was surprised at one aspect of the design: the interface to Activation stored procedures.

I would have expected the queue to be a parameted passed to the procedure rather than having to hard code the queue query into the SP.

In a system with lots of queues it seems plausible that the same activation procedure might want to be used with several queues.

Any comments?

David.

Stored procedures are compiled into execution plans that bind strictly the rowsets being involved. That means that a stored procedure cannot be compiled to issue a RECEIVE (or SELECT for the matter) against a generic 'queue', but only agains a very specific <queue_name>. This is the same reason why one cannot write a SELECT where the table name is a @.variable. The only workaround, both in SELECT and in activation case, is to use dynamic SQL, with the likely cost of having to compile the dynamic SQL when the procedure executes.

Given this it would not make sense to have the queue name passed as a parameter, it is not a performant pattern. However, if you must, there is the trick to get the queue you were activated for from sys.dm_broker_activated_tasks and build dynamic SQL to RECEIVE the messages.

HTH,

~ Remus

ACID checklist

Hi
I need an ACID checklist for database design verification. Any resources I
can go for?
Thank you,Julia,
I'm a little confused by your question. ACID is usually applied to
transactions and it means:
Atomic
Consistent
Isolated
Durable
Look up "transactions" in BOL for more information. This has little to do
with database design, but could impact stored procedure design quite
significantly. What are you trying to do?
--
Mark Allison, SQL Server MVP
http://www.markallison.co.uk
Looking for a SQL Server replication book?
http://www.nwsu.com/0974973602m.html
"Julia" wrote:
> Hi
> I need an ACID checklist for database design verification. Any resources I
> can go for?
> Thank you,
>|||what specifically do you want to know or do ?
Greg Jackson
PDX, Oregon|||I need to have a document to verify the user database is ACID compliant. It
could be a checklist to verify all related check area. I did some search but
have not found much yet. Any help would be appreciated.
"Julia" wrote:
> Hi
> I need an ACID checklist for database design verification. Any resources I
> can go for?
> Thank you,
>

ACID checklist

Hi
I need an ACID checklist for database design verification. Any resources I
can go for?
Thank you,
Julia,
I'm a little confused by your question. ACID is usually applied to
transactions and it means:
Atomic
Consistent
Isolated
Durable
Look up "transactions" in BOL for more information. This has little to do
with database design, but could impact stored procedure design quite
significantly. What are you trying to do?
Mark Allison, SQL Server MVP
http://www.markallison.co.uk
Looking for a SQL Server replication book?
http://www.nwsu.com/0974973602m.html
"Julia" wrote:

> Hi
> I need an ACID checklist for database design verification. Any resources I
> can go for?
> Thank you,
>
|||what specifically do you want to know or do ?
Greg Jackson
PDX, Oregon
|||I need to have a document to verify the user database is ACID compliant. It
could be a checklist to verify all related check area. I did some search but
have not found much yet. Any help would be appreciated.
"Julia" wrote:

> Hi
> I need an ACID checklist for database design verification. Any resources I
> can go for?
> Thank you,
>

ACID checklist

Hi
I need an ACID checklist for database design verification. Any resources I
can go for?
Thank you,Julia,
I'm a little confused by your question. ACID is usually applied to
transactions and it means:
Atomic
Consistent
Isolated
Durable
Look up "transactions" in BOL for more information. This has little to do
with database design, but could impact stored procedure design quite
significantly. What are you trying to do?
Mark Allison, SQL Server MVP
http://www.markallison.co.uk
Looking for a SQL Server replication book?
http://www.nwsu.com/0974973602m.html
"Julia" wrote:

> Hi
> I need an ACID checklist for database design verification. Any resources
I
> can go for?
> Thank you,
>|||what specifically do you want to know or do ?
Greg Jackson
PDX, Oregon|||I need to have a document to verify the user database is ACID compliant. It
could be a checklist to verify all related check area. I did some search bu
t
have not found much yet. Any help would be appreciated.
"Julia" wrote:

> Hi
> I need an ACID checklist for database design verification. Any resources
I
> can go for?
> Thank you,
>