Kbase P19188: SonicMQ: What's the impact of setting EVALUATION_MODE=true in regards to both performance and reliab
| Autor |
Progress Software Corporation - Progress |
| Acesso |
Público |
| Publicação |
15/10/2008 |
|
Status: Unverified
GOAL:
What's the impact of setting EVALUATION_MODE=true in regards to both performance and reliability with RAID 5 disks?
FACT(s) (Environment):
SonicMQ 4.x
FIX:
EVALUATION_MODE set to true allows disk writes without explicit syncing.
What does that mean:
In the case of a crash the number of messages lost is going to be controlled by the amount of buffering done by the platform/OS and so it is tough to answer.
However, more importantly there exists the risk of the broker and logs getting
out of sync. When this happens the broker will not restart.
RAID-5 is a performance killer for persistent
messages. You will get more from the disk by using RAID-10.
Furthermore, you will be able to do uptime backup with raid-10 by
spliting the mirror.