Kbase P66456: probkup -norecover while rfutil rollforward running at the same time?
| Autor |
Progress Software Corporation - Progress |
| Acesso |
Público |
| Publicação |
4/6/2004 |
|
Status: Unverified
GOAL:
Is it possible to probkup the hotspare contingency database while rfutil ai rollforward is running at the same time ?
FIX:
If the bi file(s) on the hotspare database are truncated at any time, this may cause any further ai notes to be rolled forward against the hotspare database, with resulting error messages:
** The database was last changed <day month date time>. (831)
** The after-image file expected <day month date time>. (832)
** Those dates do not match, one copy is in error. (833)
The reason is that when the timestamps in the master block are updated, the timestamps validation of the ai notes being rolled forward do not pass the validation rules. For this reason, when we need to backup the hotspare database, we must use the -norecover option. This ensures that the bi notes are backed up /as well/ and roll back recovery will then take place when this database probkup is next accessed, not before the probkup is taken (similar to online probkups).
As the probkup -norecover and the rfutil roll forward are both single user sessions, IF a probkup script is running at the same time as a rfutil roll forward script, (or vice versa) the second single user session will not be able to complete before the first single user process has completed.
In other words, it should not be possible for a probkup -norecover to be taken "mid-rfutil-roll-forward", or vice versa.
IF the hotspare database is being OS copied however, the same rules as apply to an OS copy of production or any other Progress database. The OS copy script will have to ensure that the database is not in use before taking the OS backup AND also ensure that there are there are no new processes started against the database WHILE the OS backup is taking place.
NOTE: hotspare- ,contingency- ,recovery- database are all referring to "THE DATABASE" which is used to rollforward ai notes, generated by the production database against a probkup of the live-/production- database.