We have a client with 320GB database (running FB CS v2.5) reporting performance
issues, while we are investigating possible application sources, I have been
reviewing their Firebird config.
Yesterday, I ran fb_lock_print to check on the database and found a "Mutex
wait" value of 20.9%, which I knew that a "bad thing". So, I increased (by
50%) the "Hash slots" value from 60011 to 90001.
Now, today, I checked the lock print values again, and got even worse numbers!!!
LOCK_HEADER BLOCK
Version: 145, Active owner: 0, Length: 67108864, Used:
32723368
Flags: 0x0001
Enqs: 712175161, Converts: 9327661, Rejects: 1440802, Blocks:
15963765
Deadlock scans: 9, Deadlocks: 0, Scan interval: 10
Acquires: 1133127873, Acquire blocks: 256464312, Spin count: 0
Mutex wait: 22.6%
Hash slots: 90001, Hash lengths (min/avg/max): 0/ 0/ 5
Remove node: 0, Insert queue: 0, Insert prior: 0
Owners (288): forward: 732776, backward: 29775680
Free owners (400): forward: 9817904, backward: 9548560
Free locks (28162): forward: 20344528, backward: 18378944
Free requests (293517): forward: 7727280, backward: 23127520
Lock Ordering: Enabled
Any suggestions on how I can improve the numbers?
Thanks in advance
Sean
