Step 3. Updating the LANSA Stack

The parameters discussed by this section include:

• Uninstall MSI

• Install MSI

• Update MSI

• Trigger Web Config

• Image Offer. This should never be changed from the default value. it's required only by the process of publishing the Scalable License image.

• Git Branch.

• Trace

• Fix License.

Combinations to note include:

• Uninstall MSI and Install MSI - when fixing up a defect in the MSI during development. Note that Update MSI by itself is better for a simple upgrade to the deployed application.

• Uninstall MSI and Update MSI - Update MSI requires the MSI to be installed, so don't use Uninstall MSI with Update MSI.

When re-deploying a LANSA stack, make sure all of these settings are set to the value you need.

The script that applies these settings may be found at c:\lansa\scripts\azure-custom-script.ps1 in a virtual machine created by one of these templates. Or you may visit GitHub to see the entire git repo: Branch L4W14200_scalable scripts

The order of applying these settings is the order the parameters as they are presented below:

1.  The Installing flag is set every time this script is executed. This causes the Load Balancer to detect that the VM is offline. This stops web requests from being sent to the VM, in case you have not taken the load balancer offline.

2.  If an MSI is already installed, there is a 40 second delay to wait for the load balancer to realise that the VM is offline.

3.  Trace. If it's set to N, tracing is switched off. If it's set to Y, tracing is switched on.

4.  If all other parameters, apart from Trace, are set to default values, the web server is reset to apply the new trace setting - on or off.

5.  Uninstall MSI is set to 1 and the MSI is already installed, uninstall it. On successful completion the installer file is deleted.

6.  Install MSI set to 1 will install the MSI.
If it's already installed and you did not change the MSI parameter nor replaced the MSI file with an updated version, then this will cause a repair to occur. This is not usually useful.
It's possible that you have been diagnosing an installation issue and you've fixed it and uploaded a new MSI to Azure Storage Explorer. If you also set Uninstall MSI then the old application will be uninstalled first and then the new one installed. This is important. When you construct the same MSI version you cannot install it by updating it. You must uninstall it first.

7.  If Install MSI is not set to 1 and Update MSI is set to 1, update the application. It must be a later version of an application that's already installed.

8.  If Trigger Web Config is 1, apply the Web Server Max Connect setting to the web server and reset it,

9. If Fix License it set to 1, re-create the licenses. This might be done if the web user has been changed so that that user has the right to access the license.

10. Git Branch should be left as its default value unless otherwise directed by LANSA Support.