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Hi Team, we are using sql server 2019 databases and servers are configured with HADR cluster and Always ON (AG) with multi-subnet failover option .The MultiSubnetFailover option in database connection string controls how the client attempts to connect to a database server, especially when multiple IPs are configured. To support AG listener alias connection string with multiple IPs, we need to add additional parameter: “MultiSubnetFailover=True” in DB connection string.
We need to know TimeXtender  20.39.10.64 tool is capable to support "MultiSubnetFailover=True" parameter in DB configuration or not.

Hi @info.tejavardhan ,

 

you can set additional connection properties via the advanced settings on a db connection:

 

hi  @rory.smith , we need to do this at server (project repository) level.
whenever there is failover to other server in 2 networks the failover should handle smoothy. 

Can you please confirm this is a suitable solution for our case? 

I do not have a HADR with AG available to test against - if you have one to test against you should check if it connects. I am not aware of any way to query that property to verify that it is actually set to true,

 

As far as I know setting that to Yes when not connecting to such a system is not supported by Microsoft. On my local database it fails to connect if I try that property.  Additionally I think that feature only ensures faster reconnection in a failover because it tries to connect to all subnets in parallel (and faster in single subnet because it overrides the OS limits). I do not know whether this will prevent TX giving an error due to connection loss.

As far as I know there is nothing the application itself needs to change to use that connection property, this is simply telling the SQL client library to behave differently. Perhaps @Christian Hauggaard can confirm.

 

sure @rory.smith thanks for detail.
@Christian Hauggaard , could you please opine here.

When we are using multi-sub net work, the AG listener alias working mechanism is different. When connecting is coming from TimeXtender 20.39.10.64 Application to DB server it don't know which network needs connect and it will try both Prod and DR network with round robin method. In existing case without mentioning option in additional connection properties sometime it will work and some times it will fail due to network split.

Buy using multi-subnet option we can avoid this issue. So your inputs are highly appretiated here 
@rory.smith @Christian Hauggaard @Thomas Lind 

Hi @info.tejavardhan 

Adding the option with MultiSubnetFailover in the connection properties of the databases, will be where you should set it.

We had some old tickets revolving about failover servers.

TimeXtender supports "Instance-level High Availability with Always On Fail-over Cluster Instances". 
However, it does not support "Database-level High Availability with Always On availability groups". 

So it should work as long as you us FCIs, but I am not sure you use that. It should be noted I found this in a ticket from 2020 and things may have changed since then.

Additionally, you may not have to set it specifically to true or yes, it may be able to know it automatically.

I got this info from Microsoft here. And in our prerequisites we state that you need to use .net 4.8 or higher.

hi @Thomas Lind  

mTL] However, it does not support "Database-level High Availability with Always On availability groups". 
bTeja] Currently we have our servers are set up with High Availability with Always On . It is working without any issues.

;TL] TimeXtender supports "Instance-level High Availability with Always On Fail-over Cluster Instances". 
aTeja] this is new setup we need to make , only difference is Multisubnet usage option we are trying to configure for the servers in differnt networks ( different ip’s) . Looking for your help to make this work.

:TL] use .net 4.8 or higher.

Hi @info.tejavardhan 

If it works with Always On then there is no reason to change it. The multinetsubnetfailover was also a feature of this, according to what I could find about this.

Do you know it to also work if it actually fails so it will switch to another Availability Group?

This is not a specific part of TimeXtender that you can set up in our program, it will either be something to set up on the SQL Server and then it will work for TX due to it having its databases on that, or you can add the option to turn it on as a connection property.

What will happen if it changes the IP, will it be pointing at a name for the server and then it will be another IP or will the name itself be changed?

Hi @info.tejavardhan do you have an update to Thomas’ questions above?

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