Incident Playbook Example: Investigating Failed Deployments

Created by: Kevin McCaffrey
Created on: November 7, 2024
Last Updated: November 7, 2024

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Purpose

To guide incident responders in investigating issues related to failed deployments, ensuring a consistent approach to identifying scope, impact, and root causes.

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Prerequisites

• Access to logs and monitoring tools
• Permissions to review deployment pipelines
• Understanding of the deployed system architecture

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Roles and Responsibilities

Incident Responder

• Use this playbook to systematically investigate failed deployments.
• Document findings and communicate them with relevant stakeholders.

Security Analyst

• Assess the incident for any potential security impact if applicable.
• Document security-related findings.

Operations Manager

• Ensure all personnel are trained to use this playbook.
• Maintain and update the playbook based on lessons learned.

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Step-by-Step Investigation

Step 1: Assess the Situation

1. Identify the deployment that failed (e.g., using deployment tools like AWS CodeDeploy, Jenkins, etc.).
2. Review alerts and notifications related to the failure.
3. Document the time the issue was detected and any immediate impact.

Step 2: Gather Initial Information

1. Check deployment logs for error messages or warnings.
   • Tools: AWS CloudWatch, application-specific logs
2. Review system metrics for anomalies (e.g., CPU, memory, network usage).
   • Tools: Amazon CloudWatch, AWS X-Ray
3. Validate if the failure is due to configuration issues.
   • Tools: AWS Config to review recent configuration changes

Step 3: Determine the Scope

1. Identify which services or users are affected.
2. Use monitoring dashboards to check the health of dependent services.
3. Document the impact on end users and service performance.

Step 4: Analyze Deployment Changes

1. Review the changes introduced in the failed deployment.
   • Was there a code change, configuration update, or infrastructure modification?
2. Compare with the last successful deployment to identify differences.
3. Use distributed tracing (e.g., AWS X-Ray) to track any abnormal behaviors introduced.

Step 5: Investigate Dependencies

1. Check if external services (e.g., APIs, databases) were affected or degraded.
2. Review dependency health status and any upstream/downstream impact.

Step 6: Identify Potential Root Cause

1. Analyze error logs to pinpoint the source of the issue.
2. Review recent code commits for potential issues.
3. Check for recent infrastructure changes, such as AWS CloudFormation or Terraform updates.
4. Perform a configuration rollback if necessary to test hypotheses.

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Post-Investigation Actions

Documentation

• Complete an Incident Report detailing:
  • Scope and impact of the incident
  • Root cause analysis
  • Steps taken during investigation
  • Recommendations for preventing recurrence

Communication

• Share findings with the team and relevant stakeholders.
• Update the playbook if necessary, incorporating lessons learned.

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Supporting Questions

• What error patterns emerged from the logs?
• Were there any discrepancies in configuration settings?
• Did system metrics indicate performance issues prior to the failure?

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Hand Off to Runbook

Once the root cause is determined, hand off to a Runbook for implementing the appropriate mitigation strategy, such as code fixes, configuration updates, or resource scaling.

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Artifacts

• Incident Report: Summary of findings and impact.
• Deployment Logs: Collected error messages and warnings.
• Metrics Dashboard Snapshots: Evidence of performance impact.