Kbase P103537: Should I use -Bp with online backup?
| Autor |
Progress Software Corporation - Progress |
| Acesso |
Público |
| Publicação |
07/06/2005 |
|
Status: Unverified
GOAL:
Should I use -Bp with online backup?
GOAL:
Should -Bp be used with online backup?
GOAL:
Should Private Read-only buffers be used with online backup?
FACT(s) (Environment):
Progress 9.1E
OpenEdge 10.0B
FIX:
-Bp (Private Read-only buffers) is not required with the online backup command. There is an error in the 9.1E01 Service Pack bug information where it says:
Bug# 20041203-030 Online backup performance problem has been fixed. The fix requires that the -Bp parameter is used. The minimal of -Bp 10 will suffice.
The second statement is incorrect. -Bp does not have to be used, however it can be used.
To clarify, the bug fix was two fold.
1) Do not have LRU blocks read into the -B buffer pool from disk for online backup (blocks already in the buffer pool were never moved to the LRU end). This avoids fouling the LRU mechanism of the -B buffer pool but has the "possibility" of increasing contention at the LRU end of the buffer pool (A traffic jam of sorts at the LRU end of the -B buffer chain can occur when the buffer hit ratio is low for other users on the system . This occurs when other users do lots of page ins as a normal part of their application - also something to be avoided for performance reasons but that's another discussion).
2) Honor -Bp to mitigate any possible performance issue with the solution to #1 (may or may not be needed but is the best way to go if not sure).
In summary, in 9.1E01 and 10.0B02, the -Bp parameter can be used with probkup online, but it is not required. If used, -Bp 10 is the best setting to use.