What can go wrong during a deployment?

We stated in the ‚“What can go wrong during a deployment? ‚½ of Chapter 6, ‚“Workstation and Traditional LAN Applications Step-By-Step, ‚½ that everything can go wrong. This does not get any easier in client/server because almost everything that can go wrong in a traditional application can go wrong during a client/server deployment. Now we have some additional issues to face.

Implementation

We have all lived through embarrassing implementations where a problem appears that never showed up during unit testing, system testing, user acceptance testing, or even the installation rehearsal you did the day before the real installation. This could be because of external problems or because of one you interject into the process all by yourself.

• Previous installed versions of components not being updated.

• Lack of administration tools or remote access to support administration.

• Scripts out of sync with the development database.

• Scripts run out of order.

• Scripts do not run properly.

• Database backups and restores don ‚ t work.

• DSN installed is not configured properly.

Application

The application should have been tested long before you deploy it, but during deployment you may encounter a new condition breaking the application. We strongly advise you or the designated installer run the application before turning it over to the users.

• Queries create result sets returning all records from large tables creating a bottleneck of performance.

• Remote Views in DBC are the wrong version or pointing to wrong connection.

• Remote View contention when Visual FoxPro locks view to gather view definition ( ‚“Database object is being used by someone else. ‚½ (Error 1709))

• Hard-coded server names in the data source name or connection strings in code.

• Incorrect name of database objects.

• Too many processes kicking in the MSDE performance throttle .

• DSN pointed at the wrong database.

Environment

The most difficult part of ensuring a smooth deployment is understanding the environment long before the deployment takes place. Yet we still find ourselves tripping over unanticipated problems before the fateful day.

• Backend database not installed and/or configured.

• Licensing issues with backend database.

• Missing operating system components (ODBC drivers, OLE DB provider, MDAC)

• Server hardware not optimized.

• Users not configured on server (typical on a new server).

• Security tightened down too much so users cannot access the data.

• Database administration not maintained .