微信扫一扫OCI Monitoring and Observability - Expert Knowledge
NEVER Do This
NEVER debug "missing metrics" within the first 15 minutes
- Metrics are published every 1–5 minutes
- Processing delay adds another 5–10 minutes
- Total lag from event to visible metric: 10–15 minutes
- Premature debugging creates false investigations
NEVER use = for alarm thresholds with sparse metrics
# WRONG - alarm never fires when metric has data gaps
MetricName[1m].mean() = 0
# RIGHT - handle missing data explicitly
MetricName[1m]{dataMissing=zero}.mean() > 0
NEVER omit the resourceId dimension in metric queries
# WRONG - returns no data (required dimension missing)
CPUUtilization[1m].mean()
# RIGHT - filter by instance OCID
CPUUtilization[1m]{resourceId="<instance-ocid>"}.mean()
Querying without dimensions returns data for ALL resources — usually not what's intended, and rate-limited at 1000 req/min.
NEVER set alarm thresholds without a trigger delay
# BAD - fires on every transient CPU spike (alert fatigue)
CPUUtilization[1m].mean() > 80
# BETTER - fires only on sustained breach
CPUUtilization[5m].mean() > 80
# + set trigger delay: 5 minutes (5 consecutive breaches)
NEVER create alarms without notification destinations
# WRONG - alarm fires but nobody is notified
oci monitoring alarm create ... --destinations '[]'
# RIGHT - always link to a notification topic
oci monitoring alarm create ... --destinations '["<notification-topic-ocid>"]'
Cost impact: undetected production outages = $5,000–50,000+/hour.
NEVER ignore Cloud Guard findings
- Cloud Guard detects misconfigurations before they become incidents
- Wire it: Cloud Guard → Notifications → email/Slack/PagerDuty
- Unresolved findings fail CIS/SOC2/HIPAA audits
Metric Namespace Reference
OCI uses service-specific namespaces — using the wrong namespace returns no data with no error.
| Service | Namespace | Key Metrics |
|------------------|------------------------------|------------------------------------------|
| Compute | oci_computeagent | CPUUtilization, MemoryUtilization |
| Autonomous DB | oci_autonomous_database | CpuUtilization, StorageUtilization |
| Load Balancer | oci_lbaas | HttpRequests, UnHealthyBackendServers|
| Object Storage | oci_objectstorage | ObjectCount, BytesUploaded |
Common mistake: using oci_compute instead of oci_computeagent — the agent namespace requires the OCI Compute Agent to be running on the instance.
Alarm Missing Data Handling
| Setting | Behavior | Use When |
|---------|----------|----------|
| treatMissingDataAsBreaching | Alarm fires if no data arrives | Critical services (silence = outage) |
| treatMissingDataAsNotBreaching | Alarm silent if no data | Optional or intermittent monitoring |
| {dataMissing=zero} in MQL | Treats gaps as 0 value | Request counters, throughput metrics |
Log Collection Troubleshooting
Logs not appearing in Log Analytics?
│
├─ Is logging enabled on the resource?
│ └─ Compute: is oci-compute-agent running? (systemctl status oracle-cloud-agent)
│ └─ Functions: is logging enabled in function configuration?
│
├─ Is Service Connector configured and ACTIVE?
│ └─ Source: Log Group → Target: Log Analytics
│ └─ Check status: oci sch service-connector get --id <ocid>
│
├─ IAM policy for Service Connector?
│ └─ "Allow any-user to use log-content in tenancy"
│ └─ "Allow service loganalytics to READ logcontent in tenancy"
│ └─ Missing EITHER policy causes silent failure
│
└─ 10–15 minute ingestion lag?
└─ Wait before concluding logs are missing
Metric Query Performance
Unfiltered queries scan ALL resources in compartment — slow and consumes rate limit budget.
# Expensive: scans all instances
CPUUtilization[1m].mean()
# Optimized: filter to specific instance
CPUUtilization[1m]{resourceId='<instance-ocid>'}.mean()
Rate limit: 1000 metric queries/minute per tenancy. Dashboard with many unfiltered widgets can exhaust this.
Progressive Loading Reference
Load references/oci-monitoring-reference.md when:
- Need the complete list of OCI service metric namespaces and metric names
- Writing complex MQL expressions (composites, functions, grouping)
- Implementing composite alarm conditions
- Setting up Log Analytics workspace, APM, or Service Connector Hub in detail
Do NOT load for alarm threshold patterns, namespace gotchas, or log troubleshooting — this file covers those.