Oracle Alarms May Not Fire When Minimal Workload Isn’t Met (4380206)

In Quest Foglight for Databases (Oracle), many alarms are designed to trigger only when the Oracle instance is under sufficient workload. If Foglight determines the instance is in a minimal workload state, the alarms listed below may not fire, even if their metric thresholds are reached. This prevents unnecessary alerts during periods of low activity or maintenance.

Affected Alarms

• DBO - Datafile Average Write Time
• DBO - Datafile Average Read Time
• DBO - Blocks Corrupt
• DBO - Cluster GC Convert
• DBO - Cluster GL Get
• DBO - Cluster GL Convert
• DBO - Redo Archive Average Redo Write
• DBO - Redo Archive Time to Synchronize
• DBO - Parallel Servers Busy
• DBO - Parallel Serialized
• DBO - Parallel Downgrade
• DBO - Latch Library Cache
• DBO - Latch Redo Allocation
• DBO - Latch Buffer Chain
• DBO - Latch Free
• DBO - Latch Shared Pool
• DBO - Latch Redo Copy
• DBO - Latch Library Cache Pin
• DBO - Job Queue (jobs_waiting)
• DBO - Flash Cache Hit Ratio
• DBO - Flash Cache Insert Skip
• DBO - Array Fetch (max_array_wastage)
• DBO - Session Summary Total Limit
• DBO - Process Summary Total Limit
• DBO - Redo Archive Unarchived Percentage
• DBO - Redo Archive Multiple Destination
• DBO - SGA Shared Pool Used
• DBO - Large Pool Full

When the minimal workload condition is active, you may see messages similar to:

VERBOSE [TimeDriven_Worker-3] Oracle Push Top SQL PI HOSTNAME-INSTANCE - Instance [HOSTNAME-INSTANCE] is in Minimal Workload state

in the FMS log. This indicates that alarm logic is being suppressed due to low activity.

Foglight determines minimal workload status using the registry variable Dbwc_Common_Oracle_MinimalWorkloadHighActivityThreshold, which defaults to 1.5. If the measured workload falls below this value, the environment is considered to be in a minimal workload state and alarms are suppressed.

Users can reduce the minimal workload threshold and allow alarms to fire during lighter activity by lowering the value of Dbwc_Common_Oracle_MinimalWorkloadHighActivityThreshold in the Foglight registry. For example, setting the value to 0.1 will decrease the activity threshold and allow alarms to evaluate more frequently.

How to Adjust the Minimal Workload Threshold

1. Log in to Foglight as an administrator.
2. Navigate to the Registry:
   • Open the Administration panel.
   • Select the Registry section.
3. Locate the Registry Variable:
   • Search for Dbwc_Common_Oracle_MinimalWorkloadHighActivityThreshold.
4. Edit the Value:
   • Default: 1.5
   • To reduce the threshold, set to a lower value (e.g., 0.1):

   Dbwc_Common_Oracle_MinimalWorkloadHighActivityThreshold = 0.1

5. Save and Apply Changes:
   • Click Save to apply your changes.
   • Alarms will now evaluate according to the new minimal workload threshold.

Note: Registry variables are not available for user adjustment in Foglight Cloud environments.

• This minimal workload gating logic is common in Foglight Oracle cartridges since at least the mid-2010s (e.g., Foglight 5.x and later).
• Changes take effect on the next monitoring cycle.
• Setting the threshold too low may result in excessive alarms during quiet periods; too high may suppress important alerts.
• Document all registry changes for auditing and troubleshooting.
• If unsure, contact Quest Support for guidance on optimal settings for your environment.