Most of LiveCycle’s data is held in the LiveCycle database. Backing up the database is easy – just use the native backup facilities provided by your database vendor.
Usually you can do a “hot” backup, while the application (i.e. LiveCycle) is still running. What the backup utility does is to set a “marker” in the database transaction log – the backup is the state of the entire database at the point in time the marker was set. The database will continue to run, and execute transactions, but the data from these new transactions won’t appear in the backup – so no matter how big the database is, you always get a consistent set of data.
LiveCycle is a bit more complicated, because it has the Global Document Storage directory (GDS). The GDS is really an extension or overflow for the database. For any large documents, these are actually stored in the GDS, rather than in the database – this helps with performance, and also helps to ensure that your database doesn’t grow too rapidly.
You always need to ensure that when you do a backup of your database, you do a backup of your GDS. Similarly, if you do a restore, you should also restore both the GDS and the database at the same time.
The trick is: how do you ensure that the database and GDS are consistent with each other? Any missing files in the GDS will cause LiveCycle to start throwing exceptions.
One technique is to shut down LiveCycle while you’re doing the backup. If you need to do hot backups, then there are different approaches depending on your version of LiveCycle.
LiveCycle 8 Update 1
In LiveCycle 8 update 1 (at the time of writing, in beta), Adobe have added “backup mode” to enable backups to be made more reliably. The steps are:
- Turn on “backup mode” in the adminui – this will temporarily prevent LiveCycle from deleting any files from the GDS.
- Backup the database.
- Backup the GDS.
- Turn backup mode off.
There is no backup mode in LiveCycle 8. The following procedure is the one that we recommend for hot backups.
- Backup the GDS
- Backup the database
- Backup the GDS again, to the same backup location. Ensure that you use a backup mode that adds any new or modified files, but does NOT remove any files that have been removed since the first backup.
You should also try to ensure that the entire process above occurs as quickly as possible. This may mean that you initially copy the files to a temporary location, and then perform the real backup (to tape or whatever) from there.
There is apparently a small window of possibility that errors occurs – if a file in the GDS is created and removed between the time that the first backup starts and the second backup completes. This is generally a small window. Thank you to Rob Ryan of Adobe for pointing this out.