Skip to content

Synthetic Monitoring (Canaries) for Hybrid Workloads

Last updated: 01 Jul 2025

1 · Synthetic Monitoring Methodology

  1. Discovery & Scoping
    • Identify critical user journeys (login, checkout, API health).
    • Choose geographic locations and protocols (HTTP, REST, gRPC).

  2. Script Development
    • Author canary scripts in Node.js or Python using the CloudWatch Synthetics SDK.
    • Include assertions for status codes, DOM elements, payload contents, and performance thresholds.
    • Store scripts under observability/synthetics/ in Git with PR-based reviews.

  3. CI/CD Pipeline Integration
    • Build & test canary scripts in CodeBuild: lint, unit–test (mock endpoints), and deploy.
    • On merge to main, deploy or update canaries via CloudFormation or CDK.

  4. Operation & Maintenance
    • Schedule canaries to run at business-defined intervals (e.g., every 5 minutes).
    • Implement auto-rollover of canary versions on script changes.
    • Rotate IAM roles and API keys every 90 days.

  5. Alerting & Incident Response
    • CloudWatch Alarms trigger on canary failures or SLA breaches (e.g., p95 > 1 s).
    • Alarms → SNS → Slack channel & ServiceNow incident.
    • Runbook: runbook-synthetic-failure.md outlines triage (re-run, diff script, escalate).

2 · Reference Architecture

          +---------------------+
          |  CloudWatch         |
          |  Synthetics Canary  |
          |  (Node/Python SDK)  |
   script └───► runs on schedule  │
                 every 5m         ▼
          +---------------------+      metrics &       +------------------+
          |   Canary Results    |───────────────────────►| CloudWatch       |
          |   (Screenshots,     |                        | Alarms           |
          |    Logs, Metrics)   |                        +------------------+
          +----------┬----------+                                |
                     │ logs/metrics                              ▼
                     ▼                                        +------------------+
          +---------------------+   alerts & incidents       | SNS Topic        |
          |    S3 Canary Logs   |────────────────────────────►| (finops-alerts)  |
          |  (Screenshots, raw  |                              +--------┬---------+
          |   logs)             |                                       |
          +----------┬----------+                                       |
                     │                                                  ▼
                     ▼                                        +-------------------+
          +---------------------+                              | Slack #synthetics |
          |  Athena / Glue      |  ad-hoc analysis            | & ServiceNow API  |
          |  Queries for trends |◄─────────────────────────────| webhook           |
          +---------------------+                              +-------------------+

Component Descriptions

  • CloudWatch Synthetics Runs your canary scripts in chosen Regions, captures screenshots, logs, and performance metrics.

  • S3 Bucket (synthetics-logs) Stores raw canary artifacts (screenshots, HAR files, console logs) for forensic analysis.

  • CloudWatch Alarms Trigger on metrics like FailureCount > 0 or Duration > threshold; configured via Alarm DSL.

  • SNS Topic (finops-alerts) Fan-out to Slack, ServiceNow, Email; archived for audit.

  • Athena + Glue Crawls the S3 logs daily; provides SQL-driven trend analysis of failure rates and latency.

3 · Runbook Excerpt (Embedded)

Runbook – Synthetic Canary Failure

  1. Verify: In CloudWatch Synthetics console, click “Run details” → view logs & screenshots.

  2. Re-run:
    bash aws synthetics start-canary --name user-flow-canary

  3. Compare: Diff latest script in Git against main—look for recent changes.

  4. Remediate:

  5. If assertion outdated, update script and push through CI/CD.

  6. If application issue, open dev ticket with failure snapshot.
  7. Close Alarm once next run passes; annotate incident in ServiceNow.

4 · Training & Handover

If needed, ZirconTech can provide a 2-hour workshop on: - Writing effective canary scripts
- Integrating canaries into CI/CD
- Interpreting results & maintaining scripts

Materials (slides & hands-on labs) are prepared during project kickoff and version-controlled in the customer’s repo.