SAS 9 Administration Refresher: Metadata Backups

SAS Metadata is an integral part of the design of the SAS Intelligence Platform (SAS 9.4). It functions as the “brain” of the platform, with metadata objects representing a hierarchy of all the application elements that make up the platform and their associations with each other. Fun fact: there are approximately 160 different types (SAS Namespace Submodels: Hierarchical Listing of Metadata Types :: SAS(R) 9.4 Metadata Model: Refere...) of metadata that define users, SAS libraries, tables, reports, servers and more.

The Metadata Server in SAS 9 keeps track of all these objects. It keeps track of which users can log on to the platform, use various servers, connect to data sources, and organizes all metadata content in SAS Folders.

As part of being a SAS 9 Administrator, you will need to ensure there are Metadata backups being performed at a regular interval.

Select any image to see a larger version.
Mobile users: To view the images, select the "Full" version at the bottom of the page.

Overview of the Metadata Backup and Recovery Facility

Included with SAS 9 Metadata Server is a backup utility that can be used from SAS Management Console or the command line. By default, metadata server backups are scheduled within SAS each night at 0100 hours except for Sunday. On that day, the Deployment Backup and Recovery tool takes its weekly backup, which includes the Metadata Server.

Backups may also be run on an ad-hoc basis, from either interface. The requirements are that the backup must be initiated by an unrestricted SAS Administrator. For SAS Management Console, expand Metadata Manager > Metadata Utilities > Right-click on Server Backup > Run Backup Now…

Using the Batch Tools for Metadata Server Administration (SAS Help Center: Back Up Metadata (sas-backup-metadata), you may also run an ad-hoc backup. The command sas-backup-metadata would use parameters similar to the ones below, or you may make use of a profile to supply connection information. Using the command-line Batch Tools are how you would script backups or schedule them using third-party software.

 $SASHome/SASPlatformObjectFramework/9.4/tools/admin/sas-backup-metadata \
 -host $host \
 -port 8561 \
 -user $unrestrictedAdmin \
 -password $password

Performing an ad-hoc backup using SAS Management Console and through the command-line interface both perform a backup that does not interrupt Metadata Server operation. You can run it while users are connected and going about their work, as the backup operation runs in a separate thread on the server.

Recovery

You can restore metadata from a backup using the drop-down menu in SAS Management Console by right-clicking on a successful backup and choosing Recover from this backup…

The Batch tools are another way that you could restore from one of these Metadata Server backups. The command to do so would be sas-recover-metadata SAS Help Center: Recover Metadata (sas-recover-metadata). You would need to supply a backup-name parameter as well as the connection information like the sas-backup-metadata tool.

A journaling component of the Metadata server records all transactions with the Metadata Server in a journal file. These transactions are records of all additions, modifications, or removal of metadata since that backup, until these transactions roll over at the next successful backup. When recovering you have the option to perform a Roll-Forward Recovery (or use the -rollForward option with the Batch tools). In this way you can recover changes to the Metadata Server that have occurred since the most recent backup.

During a recovery, clients cannot use the system, and it is paused to a recovery state.

Other Items of Note

Metadata is stored in SAS data sets in Metadata Repositories accessible by the Metadata server. Those SAS data sets grow in size as new Metadata objects are added to the platform. However, if those objects are deleted, the SAS data sets do not shrink in size automatically. The Reorganize Repositories option when performing backups will pause the Metadata Server, and perform some maintenance (essentially a copy and paste in-place) to recover any unused space taken up by formerly removed metadata in the Metadata Repository. By default the Monday backup has this option set.

An important part of backing up is verifying that backups have completed successfully. In SAS Management Console, expand Metadata Manager > Metadata Utilities > Server Backup and the chart of backups and restores will show in the right-hand pane. You can view the properties of these backups to view more details about verification and status.

You can also configure where the backups are being stored, through the Backup Configuration in SAS Management Console. Backups may be stored on any mounted or remote drive that the Metadata Server can access. Please don’t store your backups on the Metadata server itself, make sure they are stored elsewhere, and backed up themselves.

If you archive your backup files elsewhere manually, there is an option to Recover from an alternate location... on the Server Backup context menu. This allows you to select a backup stored outside the standard backup location.

Find more articles from SAS Global Enablement and Learning here.