Adobe CQ Help | Backing up CQ authoring servers with no downtime

Target audience	System admins, Data architects
Applicable CQ versions	All

Original backup strategy
Excessive downtime and invalid pointers
File system snapshots considered
The solution with clustered servers in a master-slave configuration
See also

An internal Adobe team arrived, through experimentation, at a workflow for maintaining a 10 GB+ CRX content repository. This repository stores documentation and assets for more than 30 Adobe products.

The backup strategy initially adopted proved ineffective:

Perform a cold backup once a week. Follow these general steps:
1. Shut down the CQ authoring server.
2. Back up files in the crx-quickstart directory to a utility server using rsync.
3. Validate the backed up files by starting CQ and performing automated regression testing.
Perform a warm backup on alternate days using the CQ online backup utility.

The weekly cold backup required an hour of downtime affecting a cross-geographic, customer-driven author community.

Further, as the CRX repository size approached 10 GB, ZIP archives created by the online backup utility could no longer be used to restore the system. This issue arose because the system remained in active use during the backup, leading to invalid pointers in the backup ZIP archives.

The team first considered using file system snapshots to resolve the issues. This approach requires the use of Logical Volume Managers to create the file system. File system snapshots can be created in a few seconds and do not entail server downtime.

However, this approach was discarded because it was not compatible with the authoring server file system.

The internal Adobe team resolved the issue by clustering the CQ authoring servers in a master-slave configuration. The team performs a cold backup weekly, while warm backups are taken every weekday.

To perform backups, the team shuts down the slave authoring server and backs up its files using rsync. During this time, all traffic is routed to the master authoring server.

This strategy enables convenient cold backups without causing any server downtime.