Overview
The
Online backups can be performed when the database is active for both read and write access. As recovery journal files are used during the recovery process to recover the database to a fully consistent state, recovery journals must be retained and the database informed when the backup starts and completes. All file backups must occur within the bounds of a backup transaction.
The JadeDatabaseAdmin class enables you to create backup tools that provide:
-
Full online backup to disk. (Backup to other media is not supported.)
-
Support for multiple backup destinations, backup concurrency, and data compression. (No support is provided for partial or incremental backup, or for third-party backup tools.)
-
A simple backup service in the RootSchema.
Although you can use the administration framework provided by the DbFile and JadeDatabaseAdmin system classes to build standalone database administration applications, you can integrate the online backup service provided by JADE directly in any of your applications, to reduce your development work.
You can backup multiple files concurrently. Concurrent file backups enable your backup applications to take advantage of parallel I/O, which you can use to reduce the elapsed time required for a backup. Your backup applications are responsible for initiating simultaneous file backups, if required, using multiple JADE processes.
Each file backup operation executes as a database method on the server, utilizing a separate server thread. However, because of increased disk contention and disk head movement, concurrent backup operations run slower if source and destination files are not on separate disk devices.
A one-to-one correspondence between application threads and server threads does not exist. A file backup task is scheduled to run from the pool of available server threads, which means that in some cases backup application threads will be blocked waiting for an available server thread.
| For details about… | See… |
|---|---|
|
|
|
| Event notifications | " |
| JADE development environment online backups | " |
| Backing up and restoring the database | " |
