OEM 13.5 – Alert Noise Reduction (UI Configuration)

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🔧 1. Configure Metric Thresholds (First & Most Important)

👉 This is where most alert noise comes from.

📍 Navigation:

Targets → Databases → Select your DB → Monitoring → Metric and Collection Settings

🪜 Steps:

1. Search for a metric (e.g., CPU Utilization, Tablespace Used (%))

2. Click Edit (pencil icon)

3. Set thresholds properly:

   • Warning: e.g., 80%

   • Critical: e.g., 90%

4. Set Occurrences (very important):

   • Example: Trigger only if 3 consecutive collections fail

5. Click OK → Save

💡 Tip:

• Use “Occurrences > 1” to avoid false alerts (flapping)

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🔁 2. Configure Incident Rules (Event Grouping / Compression)

👉 This is the real “alert compression engine”

📍 Navigation:

Setup → Incidents → Incident Rules

🪜 Steps:

1. Click Create Rule Set

2. Name it (e.g., DB_ALERT_COMPRESSION)

3. Click Create Rule

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🔹 Rule Configuration:

Condition:

• Target Type = Database Instance

• Severity = Critical / Warning

Actions:

• ✔ Create Incident

• ✔ Add to existing open incident (IMPORTANT)

• ✔ Set Incident Priority

👉 This ensures:

Same issue → 1 incident instead of many alerts

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🔕 3. Configure Notification Rules (Avoid Spam Emails)

📍 Navigation:

Setup → Notifications → Notification Rules

🪜 Steps:

1. Click Create

2. Define:

   • Target (DB / Host)

   • Event Type (Metric Alert)

   • Severity (Critical only recommended)

3. Configure:

   • Send email only for Critical

   • Suppress Warning alerts (optional)

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💡 Pro Tip:

• Send:

  • Warning → Dashboard only

  • Critical → Email/SMS

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⛔ 4. Configure Blackouts (Maintenance Mode)

👉 Prevent alerts during planned work

📍 Navigation:

Enterprise → Monitoring → Blackouts

🪜 Steps:

1. Click Create Blackout

2. Select Target (DB / Host)

3. Define:

   • Duration (e.g., 2 hours)

4. Enable:

   • ✔ Stop monitoring

   • ✔ Suppress alerts

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✅ Result:

No alerts during:

• Patching

• Restart

• Maintenance

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🔄 5. Configure Corrective Actions (Auto-Healing)

👉 Stops repeated alerts automatically

📍 Navigation:

Targets → Database → Monitoring → Metric and Collection Settings

🪜 Steps:

1. Select a metric (e.g., Listener Down)

2. Click Edit

3. Go to Corrective Actions

4. Add script:

Example:

lsnrctl start

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💡 Result:

• Issue auto-fixed

• Alert doesn’t repeat

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🔍 6. Enable Event De-duplication & Correlation

👉 Mostly automatic but configurable

📍 Navigation:

Setup → Incidents → Incident Rules → Advanced Settings

🪜 Steps:

1. Enable:

   • ✔ Event de-duplication

   • ✔ Event correlation

2. Define time window (e.g., 5–10 mins)

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💡 Example:

• Same alert every minute
  ➡️ Only one incident shown

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📊 7. Validate Configuration

📍 Navigation:

Enterprise → Monitoring → Incidents

Check:

• Alerts grouped properly

• No duplicate incidents

• Reduced alert count

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🎯 Real Production Setup (Recommended)

Feature	Setting
Threshold Occurrence	3
Incident Grouping	Enabled
Notifications	Critical only
Blackouts	Mandatory
Auto-healing	Enabled

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🧠 Interview-Ready Answer

👉 “How do you reduce alert noise in OEM?”

Answer:

“I tune metric thresholds with occurrence settings, configure incident rules to group alerts, use notification filtering to avoid unnecessary emails, apply blackouts during maintenance, and enable corrective actions to auto-resolve recurring issues.”

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🚀 Final Thought

“OEM is powerful… but without tuning, it becomes noisy.
A good DBA makes OEM quiet but intelligent.”

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