In this exercise you will trigger the application of a LANSA Upgrade to all the Web Server instances. As it's an exercise you may do this at any time, but with a production system you would schedule a time to perform this maintenance activity and take the application offline and perform tests to ensure your application is still working as expected.
N.B. The AWS Console status will change to UPDATE_COMPLETE when the FIRST part of the process is complete. That is, it's updated the definition of the stack. The actual action you have requested is not started until the next time the agent on the EC2 instance checks for changes. This occurs at 1 minute intervals. The action must then be executed. How long the action takes to execute is dependent on what you have asked it to do. It may take many minutes.
Also, only apply one trigger at a time and allow sufficient time for the action to complete before applying another trigger.
Before You Begin
You must have completed the following exercises:
CTE040 – Create the LANSA Stack
CTE030 – Upload your LANSA WAM Application (but to upload your new MSI)
The upgrade for your application must have been uploaded already. You can follow the same procedure as explained in CTE030 – Upload your LANSA WAM Application. The same S3 folder should be used as was used for the first installation.
It's important to understand that the DBWebServer instance must be fully upgraded before attempting to update the WebServer stack. This is because all database changes must be applied only by DBWebServer and must be completed before the WebServer stack attempts to use those changes.
Hence the two nested stacks are updated rather than the parent stack.