Kbase P99224: Database is abnormally shutdown with errors (3817) (3818) (3819) (3822)
| Autor |
Progress Software Corporation - Progress |
| Acesso |
Público |
| Publicação |
11/5/2007 |
|
Status: Unverified
SYMPTOM(s):
Database is abnormally shutdown with errors (3817) (3818) (3819) (3822)
dpend: sdpend: dbkey: (3817)
dpend: sdpend dbkey: (3818)
rlwritten: , rldepend: (3819)
SYSTEM ERROR: rlputmod: dpend already written (3822)
Database re-starts without any problems
CAUSE:
The problem only occur when there are no free bi buffers and does not indicate database corruption. It is a race condition in that two user's processes try to put the current bi output buffer on the bi modified buffer list at the same time. This race condition only occurs if there are no free bi buffers.
FIX:
Add more bi buffers to the database startup parameters and run the BIW utiliity.
In addition to having a lot of bi buffers, it is important to run a BIW writer and have well tuned asynchronous page writer(s). When more bi buffers are added, it is less likely that they will all be on the filled bi buffer list. Most importantly, the page writer(s) should not be overly aggressive, ie flush modified buffers as soon as they are modified.
The -bibufs parameter can be increased to 30 or higher. There is no "rule of thumb" regarding how high to set the -bibufs parameter, however 30 is good for most databases. If after setting -bibufs to 30 the errors re-occur, set -bibufs higher to 50 or higher. Each bi buffer takes up 1K of memory. There are no adverse consequences to setting -bibufs too high, although anything over 1,000 is likely excessive and would be using up memory unnecessarily.