Hi, I’m Raluca, and today I’m going to tell you a bit about code snapshots.
Primarily, a snapshot is a quick photograph taken with a camera or a phone, but it can also mean a piece of information that gives an understanding of a situation at a particular moment.
In migration projects, we use this term to illustrate the state of a system or a system’s functionality. So, a snapshot refers to the state of the code and a number of other important related artifacts at a certain point in time.
There are 4 elements that we should consider when talking about snapshots:
1) all source code of all different types: for example business programs and supporting scripts, including the screens – that are delivered according to clearly specified guidelines.
2) code data structures
3) (test) data
4) test cases
And, from experience, we know that it is extremely important that all of these artifacts are frozen at the exactly same time and are completely in sync. We call this coherence.
Secondly, and equally important, the snapshot must be 100% complete: there can be no artifacts missing. So, every single module or program called should be part of the snapshot.
Once the snapshot is created, it is typically transferred to the Factory (see the Migration Factory video). Here, it is used to migrate and test according to Migratonomy, which is our methodology.
It is important to understand that creating a snapshot does not interfere with evolutionary application maintenance of the legacy application, and the work can continue as if nothing happened.
In a migration project, several snapshots are taken while the project progresses - typically 4 - and this to stay current with the then-current production environment.
That’s it for now. Thanks for watching and visit our website anubex.com for more resources on mainframe modernization.
