Kbase P112684: How to add extents to source and target databases with minimum downtime
| Autor |
Progress Software Corporation - Progress |
| Acesso |
Público |
| Publicação |
1/19/2006 |
|
Status: Verified
GOAL:
How to add extents to source and target databases with minimum downtime
GOAL:
How to change source and target structure in a replication environment with minimum downtime
FIX:
It takes longer to prorest a backup when the structure for the new database has to be created at the same time. A prorest into an existing structure is faster, since the process doesn't have to format database blocks from scratch, for example.
In the example process below from a Fathom Replication environment, the source database is updated with additional data extents, corresponding changes are carried out the target, and replication is restarted. This method decreases the time that the replication configuration is down.
1. Shutdown source (proshut source -by)
2. Perform a full offline backup of source (probkup source sourcebak00)
3. Disable site replication on source (proutil source -C disableSiteReplication source); remove source.repl.recovery
4. Truncate the BI on source (proutil source -C truncate bi)
5. Add additional data extents to source (prostrct add source srcadd.st)
6. Update the source Live DB structure file (prostrct list source)
7. Enable site-replication on the source Live DB (proutil source -C enableSiteReplication source)
8. Perform full offline backup of the source (probkup source sourcebak01)
9. Shutdown target (proshut target -by)
10. Disable site replication on target (proutil target -C disableSiteReplication target)
11. Truncate the BI on the target Live DB (proutil target -C truncate bi)
/* Up to this point it would have been possible to restart replication as is, as long as the logical structure of the source and target are still the same, i.e. if no new areas have been added under (5). After truncating the BI such a restart is no longer possible. */
12. Add the additional data extents to target (prostrct add target trgtadd.st)
13. Update target structure file (prostrct list target)
14. Perform prorest of the full backup created under (8), overwriting the existing target (prorest target sourcebak01)
15. Enable site-replication on target Live DB (proutil target -C enableSiteReplication target)
16. Restart target (proserve -db target -DBService replagent -S 4501)
17. Restart source (proserve -db source -DBService replserv)
If instead of (11) onwards, the target had been first deleted, then the prorest would have had to create the database structure as well (formatting blocks etc.), thus increasing the replication downtime. The method outlined here should be considered for use especially when the large databases are involved, and should result in some time-saving.