Article Original Creation Date: 2010-11-03

Overview

Customer needs to know the amount of time it will take for migration of SG 4.0 to 4.1 and back. They require this rollback because of fails in production, so the scripts and functions also need to convert IPv6 to IPv4 format addresses.

In this case, the customer has 1 million active modems, and more in the database.

Environment

ServiceGateway 4.x

Information

It’s impossible to judge with any accuracy the speed of the IP conversion on a system. It is performed by an update statement which uses a PL/SQL procedure and thus is entirely dependent on the speed of the Oracle database.

It’s entirely possible it could take several hours (or more), so we strongly suggest benchmarking this well ahead of the upgrade, so that you can decide how to proceed if it would cause the maintenance window to overrun.

Possible alternatives are running multiple conversions in parallel on distinct ranges of records or performing the conversion ahead of time and doing a final update of only those records that have changed during the upgrade window. An alternative approach would be considered custom work.

The only supported rollback approach for 4.1 is the restoration of a database backup. Due to the considerable schema changes and the data migration, anything less would incur too much risk of data corruption.

However, we do understand that a database backup and restore would take too long in some cases, and in those cases, we can look at other options/providing some extra scripts.

Converting the IPv6 format back to IPv4 would be expected to take the same amount of time as the forward conversion, so keeping the IPv4 addresses in case a rollback is necessary is likely the better approach.