Lock Requests that Wait (LockWaitRatio)
The LockWaitRatio parameter reports the percentage of lock requests that wait. The annotation for this parameter reports all the delta values that were used in the calculation for the current polling cycle.
Recommendations
If there is a contention on enqueue resources, increase the init.ora enqueue_resources parameter.
When setting the enqueue_resources parameter, allow one process per resource, regardless of the number of sessions or cursors using the resource, not one per lock.
Use the following table to select the appropriate value for enqueue_resources:
If init.ora processes value is... | Set enqueue_resources default value to... |
|---|---|
3 or less | 20 |
between 4 and 10 | [(processes - 3) * 5] 20 |
greater than 10 | [(processes - 10) * 2] 55 |
Do not assign enqueue_resources a value greater than the sum of the init.ora parameters (dml_locks ddl_locks).
Thresholds for alarms and warnings
Item | Default threshold | State |
|---|---|---|
Border range | 0-0 | OK |
Alarm1 range | 10-20 | WARN |
Alarm2 range | 20-100 | ALARM |
BMC PATROL properties
Attribute | Default value |
|---|---|
Application class | ORACLE_PERFORMANCE |
Command type | Not applicable |
Platform | All |
Icon style | Graph |
Unit | Percentage of lock requests |
Border range | 0-0 OK |
Alarm1 range | 10-20 WARN |
Alarm2 range | 20-100 ALARM |
Scheduling(poll time) | Poll time of collector |
Active at installation | Yes |
Parameter type | Consumer |
Value set by | CollPerformance |
BMC ProactiveNet Performance Management properties
Property | Default value |
|---|---|
| Monitor type | Oracle Database Performance |
| Key Performance Indicator | No |
| Monitor for abnormalities | Yes |
| Graph by default | No |
| Availability | No |
| Response time | No |
| Normal distribution | Yes |
| Statistical | Yes |
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