Tuesday, March 27, 2012
Basic Parameter
will contain 5 numeric digits. As the user starts typing i.e. a 3 I would
like to see 30000 appear, then if they type a 1 then 31000 will appear, next
if they type a 2 then I would see 31200 then a 5 they would see 31250 and
lastly if they typed a 1 then 31251 would appear in the list and when they
hit enter that would be the number of the work order that appears.
Thank you.On Nov 8, 3:49 pm, NormaD <Nor...@.discussions.microsoft.com> wrote:
> This is a beginning type of question - I am trying to set up a parameter that
> will contain 5 numeric digits. As the user starts typing i.e. a 3 I would
> like to see 30000 appear, then if they type a 1 then 31000 will appear, next
> if they type a 2 then I would see 31200 then a 5 they would see 31250 and
> lastly if they typed a 1 then 31251 would appear in the list and when they
> hit enter that would be the number of the work order that appears.
> Thank you.
Unfortunately, this type of functionality does not exist in SSRS/
Reporting Services (aside from standard auto-complete in your browser,
which isn't quite the same thing). The best way to create this
functionality is to create a custom ASP.NET application that does this
via callback/postback. Sorry that I could not be of greater
assistance.
Regards,
Enrique Martinez
Sr. Software Consultant
Tuesday, March 20, 2012
Balancing scalability with availability
We are beginning to design a new application with SQL Server 2005. Our current production environment is slated to be two SQL Server 2005 machines with the databases residing on an EMC SAN. We have requirements to both have automatic failover between servers for availability and also be able to balance the load over two hot servers for scalability.
Can anyone point me in the right direction for things I need to consider in order to be able to implement both of these requirements? Can I implement database mirroring (for failover) and transactional replication (for balancing) given the hardware configuration I'v mentioned? Is more information needed? Where should I turn next?
I am coming off a mainly Oracle background for the last ten or so years with a smattering of SQL Server mixed in. I've tried to hit the ground running on this project, but sometimes find myself hitting the wall running instead.
Thanks,
Larry
Automatic failover can be accomplished with Database Mirroring, and clustering. With both of these technologies the mirrored server or the failover node will be offline so you can't access the databases on these mirrored servers - hence they won't deliver load balancing. For load balancing you could use replication assuming all the DML occurs on one server. Replication will not provide client failover however.
-- Hilary Cotter
|||That is not correct.
The instance hosting the mirror database is NOT offline. It is online and running otherwise transactions would not be able to reach it. The mirror database is inaccessible, because it is in a recovering state.
As far as clustering goes, the secondary node is also not offline. It is online and functioning, otherwise, there would be no way to failover to the node. There is only one copy of the database within a cluster, so you can't use the secondary node to execute anything.
The combination that is being asked for - automatic failover along with scalability is not possible. Failover clustering will automatically failover, but is not a scalability solution. Database Mirroring running in high availability operating mode will automatically failover, but is not a scalability solution. However, if your applications are not coded to intercept the disconnect and then reconnect to the cluster, it doesn't matter if the cluster automatically fails over, because only those applications forming new connections will find it. If your applications are not coded to utilize the new connection library in ADO.NET that shipped with VS 2005, then your applications are not going to automatically failover to the mirror when it gets promoted.
Replication is your closest bet to getting both fault tolerance as well as scalability. If your applications are built with a connection library that can detect that the server they are connected to is offline and then reform a connection to a secondary server and continue issuing transactions, then you can accomplish the basic goals. Your application then handles the automatic failover while the replication engine keeps everything synchronized to allow scalability. The basic options here are transactional with queued updating subscribers and merge. I would NOT configure a bi-directional or peer-to-peer architecture unless your are going to have full control over your applications and can guarantee that you can never have a conflict generated.