To prevent an unforeseen technical mishap from damaging or destroying your catalogs you should have a strategy. Cumulus offers the following mechanisms to preserve catalog data in case of a failure:
• Backing up
• Journaling
• Mirroring
Canto recommends you to backup your catalogs regularly and in addition, to avoid losing changes made to a catalog after the most recent backup, employ either catalog journaling or mirroring as a second mechanism. Which mechanism is best depends on your needs.
The advantage of journaling is that you can immediately continue working after a failure.
Use mirroring for a catalog that is intended to serve as a ‘caching engine’ which for example saves data into an external SQL-compatible database Or with a second Cumulus Server, you can use mirroring for failover functionality and load balancing. The disadvantage of mirroring is that rebuilding a catalog from its mirror database might be very time consuming. (For a description on how to rebuild catalogs from mirrors, see “Repairing Catalogs” .)
IMPORTANT! Do not employ journaling and mirroring for the same catalog! Use one of the mechanisms depending on how the catalog is used.
For backing up your catalogs regularly, Canto recommends you to use the Cumulus Backup Manager and in addition, to have rotating backups, you should include the catalog files in your regular system backup provided by your server platform. (For a description on how to use the Backup Manager, see “Backup Manager” .)
TIP: Avoiding Improper Shutdowns of the Cumulus Server
To avoid improper shutdowns of the Cumulus Server always stop the Cumulus Server before you make any changes to the operating system that might cause a shut down of the system (e.g. updates). Shutting down the Cumulus Server might take a while depending on the number and size of catalogs managed by the Cumulus Server. Do not interrupt the shutdown process! Windows only: When stopping a Cumulus Server under Windows check that the Cumulus Server service has stopped. You can check this either via the Services Control Panel using the Refresh function (F5) or via the Task Manager (no Cumulus Server.exe in the processes list.) UNIX only: When you are stopping a Cumulus Server under UNIX and stop-cumulus.sh runs into a time-out, use status.sh to check that the Cumulus Server has stopped.
The next sections give more details on the journaling and mirroring mechanisms and describe how to activate them.
Windows only: When stopping a Cumulus Server under Windows check that the Cumulus Server service has stopped. You can check this either via the Services Control Panel using the Refresh function (F5) or via the Task Manager (no Cumulus Server.exe in the processes list.)