The SAS 9.3 Metadata Server
includes a server-based facility that can be used to perform unassisted,
scheduled SAS Metadata Server backups. These backups do not interrupt
the regular operation of the metadata server. The facility can perform
ad hoc backups, restores, and roll-forward recovery of the SAS Metadata
Server from the metadata server journal.
The server-based facility
includes the following:
-
Options on IServer methods. These
options perform the following functions:
-
set the backup configuration and
backup schedule, and enable clients to execute ad hoc backups and
restores.
-
return requested information about
the backup configuration, backup schedule, backup history, and specific
backup and restore operations.
-
Internal processes for scheduling
and executing backups and recoveries.
-
Four system files in the
SASMeta/MetadataServer directory that manage backup
and recovery processes.
-
MetadataServerBackupConfiguration.xml contains the backup
configuration and backup schedule.
-
MetadataServerBackupHistory.xml contains a history of
backup and recovery activity.
-
MetadataServerBackupManifest.xml contains a record of
the repositories and files copied in a backup.
-
MetadataServerRecoveryManifest.xml contains a record
of the repositories and files copied in a recovery.
CAUTION:
These four
system files should never be opened directly.
Use the functionality
in the SAS Management Console Metadata Manager to view information
or use SAS to issue appropriate Status method requests through PROC
METADATA to list all or some of the content of these system files.
-
An omaconfig.xml option, <OMA
JOURNALTYPE = “NONE | SIMPLE | ROLL_FORWARD”/>, that
is used to configure roll-forward recovery from the metadata server
journal. ROLL_FORWARD is the default journal type setting for SAS
9.3 installations.
The facility always
performs a full backup of the SAS Metadata Server. A full backup includes
all configuration files in the
SASMeta/MetadataServer directory, and all SAS metadata repositories that are registered
on the SAS Metadata Server, regardless of their registered access
modes.
In addition to backups
of repositories and configuration files, each backup directory contains
a MetadataServerBackupManifest.xml file. And, when roll-forward recovery
is configured, the backup directory contains a metadata server journal
file. The MetadataServerBackupManifest.xml file contains a record
of the files that were backed up. This enables recovery processes
to verify that nothing in the backup has changed since the backup
was performed The metadata server journal file is created in the backup
directory when the backup is initiated. The metadata server journal
file records transactions that occur while the backup is being performed.
When the backup completes, those transactions are applied to the backup.
The metadata server journal file records subsequent transactions until
the next backup is performed. Locating the metadata server journal
file in the backup directory ensures that each backup directory has
all of the information that is necessary to recover the server between
backups.
The facility supports
full recovery from the metadata server journal file, or recovery up
to a specified point in time. The SAS Metadata Server log should be
used to determine the datetime value to use for the recovery. The
server accepts a SAS datetime value in GMT. The SAS Management Console
Recover from a Backup wizard can help you format the datetime value.
When roll-forward recovery
is not configured, no metadata server journal file is used. The server
is placed in a READONLY state while backups are performed.
The backup configuration
and backup schedule are set with the Refresh method. They are monitored
with the Status method. For more information, see
Refresh, Status, Pause, and
Resume.