Takeover procedures, Planned takeover – HP Integrity NonStop J-Series User Manual
Page 232
Operations and Management
HP AutoSYNC User’s Guide—522580-017
A-14
Takeover Procedures
The =_AUTOSYNC_SYSDB DEFINE is class CATALOG and specifies a subvolume
for the SysDB tables. If this DEFINE is present when AUTOSYNC is started, it does
not look for the normal SysDB, but uses the one specified. Thus, it operates only with
MapDBs and monitor processes that are created under the specified SysDB.
A typical =_AUTOSYNC_SYSDB DEFINE is added by using the following TACL
command:
Takeover Procedures
AutoSYNC is commonly used in conjunction with database-replication products to
provide complete business continuity and disaster recovery. Those products provide
various methods to discontinue the replication process and to bring the database into a
consistent state; this is commonly known as a takeover. This section describes the
basic steps to perform a takeover of AutoSYNC processing.
For the purpose of describing the takeover steps, we label the current primary system
or source system as \P, and the current backup system or destination system as \B.
The takeover instructions in the paragraphs below assume that Syncusers and Syncfile
sets are correctly configured on both system \P and system \B. It is recommended to
review these configurations periodically, for accuracy and completeness.
For safety, users should implement procedures for planned and as well as unplanned
takeovers.
Planned Takeover
The primary operation for a planned takeover is to terminate the ongoing scheduled
synchronization from the source system \P to the destination \B, and reverse the
processing from the new source \B to the new destination \P.
On the primary system \P:
1. Check the status of on-going synchronizations:
•
, DETAIL
•
, LOG LAST n;
If any errors have been reported, resolve them before attempting the takeover.
2. Suspend the syncusers and synchronizations to prevent additional synchronization
before you switch processing to the new primary system:
•
ALLUSERS;
ADD DEFINE =_AUTOSYNC_SYSDB,CLASS CATALOG,SUBVOL $vol.mysysdb