Kbase P88543: Database hangs due to excessive bi checkpointing
| Autor |
Progress Software Corporation - Progress |
| Acesso |
Público |
| Publicação |
11/21/2008 |
|
Status: Verified
SYMPTOM(s):
_mprosrv hangs
Existing remote connections hang
Many blocked clients in promon
Stack trace from _mprosrv reads:
latXlock
latlatch
dbDelUsrctl
dbenvout
FACT(s) (Environment):
Progress 9.1D
All Supported Operating Systems
CAUSE:
Bi checkpointing is occurring too often and the bi cluster size may be too small.
FIX:
1. Run promon db-name with the db running
2. Type R&D, Option 3 Other Displays, Option 4 Checkpoints
3. If the Len is less than 3-5 mins, the checkpointing, or writing of modified
buffers to disk, is happening too frequently and causing a performance hit.
4. Make sure a biw and a few apws are started on database startup (Enterprise
license only):
pro apw
pro apw
pro apw
pro biw
5. If the bi cluster size is below the default of 524K, increase it using this
command until the time between checkpoints increases to 3-5 minutes (the db
has to be shut down first):
proutil db-name -C truncate bi -bi size
size = Specifies the size of the cluster in kilobytes. The number must be a multiple of 16 ranging from 16 to 262,128 (16K to 256MB). The default cluster size is 524K. If you use a value that is not a multiple of 16, PROUTIL rounds the value up to the next multiple of 16.