Smoke Test Database Skill

Quick Reference - Load this first for fast context (~3KB)

Mission

Execute comprehensive database smoke tests to validate connectivity, query performance, data integrity, and backup/restore operations during release workflows.

Core Capabilities

• Connection Testing: Validate database connectivity and authentication
• Query Performance: Test read/write operations against SLA targets
• Schema Validation: Verify database schema matches expected structure
• Data Integrity: Check critical data constraints and relationships
• Replication Health: Validate primary/replica synchronization
• Backup Validation: Verify backup operations and restore capability

When to Use This Skill

Use this skill when:

• Executing pre-release smoke tests (verify database readiness)
• Validating post-deployment health (after migrations)
• Testing canary deployments (database connection pooling)
• Verifying rollback success (schema rollback validation)
• Running scheduled health checks (monitoring integration)

Quick Start

1. Load Skill in Agent

skills:
  - name: smoke-test-database
    path: skills/smoke-test-database/SKILL.md

2. Execute Database Tests

const { SmokeTestDatabase } = require('./scripts/test-connectivity.js');

const tester = new SmokeTestDatabase({
  type: 'postgresql',  // or 'mysql', 'mongodb', 'redis'
  host: 'localhost',
  port: 5432,
  database: 'staging_db',
  username: 'app_user',
  password: process.env.DB_PASSWORD
});

const result = await tester.executeTests({
  environment: 'staging',
  tests: ['connectivity', 'query-performance', 'schema-validation']
});

if (result.passed) {
  console.log('✅ Database smoke tests passed');
} else {
  console.error('❌ Database smoke tests failed');
}

3. Configuration Template

environment: staging
database:
  type: postgresql
  host: staging-db.example.com
  port: 5432
  database: app_staging
  username: app_user
  password: ${DB_PASSWORD}
  ssl: true
  poolSize: 10
tests:
  - connectivity
  - query-performance
  - schema-validation
  - data-integrity

Database Smoke Test Categories

1. Connectivity Tests

• Primary connection: Connect to primary database
• Replica connection: Connect to read replica
• Connection pooling: Validate pool size and idle connections
• SSL/TLS validation: Verify encrypted connections
• Authentication: Test credentials and permissions

2. Query Performance Tests

• Simple query: SELECT 1 (target: ≤10ms)
• Table query: SELECT * FROM users LIMIT 1 (target: ≤50ms)
• Join query: Multi-table join (target: ≤200ms)
• Index usage: Verify indexes are used (EXPLAIN analysis)
• Write operations: INSERT/UPDATE/DELETE (target: ≤100ms)

3. Schema Validation

• Table existence: Verify all required tables exist
• Column validation: Check columns, types, constraints
• Index validation: Verify indexes exist and are valid
• Foreign key constraints: Check referential integrity
• Migration status: Verify all migrations applied

4. Data Integrity Tests

• Record counts: Validate expected data volume
• Constraint validation: Check NOT NULL, UNIQUE, CHECK constraints
• Referential integrity: Validate foreign key relationships
• Critical data: Verify essential configuration records
• Data consistency: Check for orphaned or duplicate records

5. Replication Health

• Replication lag: Measure primary-replica lag (target: ≤1s)
• Replica status: Verify replicas are connected and healthy
• Data consistency: Compare row counts across replicas
• Failover readiness: Test replica promotion capability

6. Backup Validation

• Backup recency: Verify last backup timestamp (target: ≤24h)
• Backup integrity: Validate backup file checksums
• Point-in-time recovery: Test PITR capability
• Backup restoration: Verify restore to test environment

Performance SLAs

const SLA_TARGETS = {
  connectivity: 1000,     // Connection: ≤1000ms
  simpleQuery: 10,        // SELECT 1: ≤10ms
  tableQuery: 50,         // Table scan: ≤50ms
  joinQuery: 200,         // Multi-table join: ≤200ms
  writeOperation: 100,    // INSERT/UPDATE/DELETE: ≤100ms
  replicationLag: 1000,   // Replication lag: ≤1000ms
  timeout: 30000          // Global timeout: ≤30000ms
};

Pass/Fail Criteria

Pass: All smoke tests must pass

• ✅ Database connections established successfully
• ✅ All query performance SLAs met
• ✅ Schema matches expected structure
• ✅ Data integrity constraints satisfied
• ✅ Replication lag within acceptable limits
• ✅ Recent backup exists and is valid

Fail: Any smoke test failure blocks deployment

• ❌ Connection failures or authentication errors
• ❌ Query performance exceeds SLA targets
• ❌ Missing tables, columns, or indexes
• ❌ Data integrity violations detected
• ❌ Replication lag exceeds threshold
• ❌ Backup missing, stale, or corrupted

Execution Points

Database smoke tests are executed at these points in the release workflow:

1. Pre-Release (before staging deployment): Validate database readiness and migrations
2. Post-Staging (after staging deployment): Verify database health after deployment
3. Canary 5% (5% traffic): Test database connection pooling with minimal load
4. Canary 25% (25% traffic): Validate database performance under moderate load
5. Canary 100% (100% traffic): Test database at full production load
6. Post-Production (after production deployment): Verify production database health
7. Post-Rollback (after rollback): Validate rollback database state and schema

Common Patterns

Pattern 1: Simple Connectivity Test

const result = await tester.testConnectivity({
  timeout: 5000,
  retries: 2
});

Pattern 2: Query Performance Test

const result = await tester.testQueryPerformance({
  queries: [
    { sql: 'SELECT 1', sla: 10 },
    { sql: 'SELECT * FROM users LIMIT 1', sla: 50 }
  ]
});

Pattern 3: Schema Validation

const result = await tester.validateSchema({
  tables: ['users', 'products', 'orders'],
  checkIndexes: true,
  checkConstraints: true
});

Pattern 4: Data Integrity Check

const result = await tester.validateDataIntegrity({
  checks: [
    { table: 'users', expected: { min: 100, max: 1000000 } },
    { table: 'products', constraint: 'price > 0' },
    { query: 'SELECT COUNT(*) FROM orders WHERE user_id NOT IN (SELECT id FROM users)', expected: 0 }
  ]
});

Output Format

{
  passed: true,
  details: {
    totalTests: 6,
    passed: 6,
    failed: 0,
    executionTime: 1234
  },
  reason: 'Database smoke tests passed: All 6 tests passing',
  metrics: {
    testsPassed: 6,
    testsFailed: 0,
    averageQueryTime: 45,
    maxQueryTime: 198,
    executionTime: 1234
  },
  results: [
    {
      test: 'connectivity',
      category: 'Connection',
      passed: true,
      duration: 234,
      sla: 1000
    },
    {
      test: 'query-performance',
      category: 'Performance',
      passed: true,
      duration: 45,
      sla: 50,
      details: {
        queries: 5,
        averageTime: 45,
        maxTime: 198
      }
    }
  ]
}

Database Type Support

PostgreSQL

• Connection: pg driver with connection pooling
• Schema validation: information_schema queries
• Performance: EXPLAIN ANALYZE for query plans
• Replication: pg_stat_replication monitoring

MySQL

• Connection: mysql2 driver with connection pooling
• Schema validation: INFORMATION_SCHEMA queries
• Performance: EXPLAIN for query plans
• Replication: SHOW SLAVE STATUS monitoring

MongoDB

• Connection: mongodb driver with connection pooling
• Schema validation: Collection and index validation
• Performance: explain() for query plans
• Replication: Replica set status monitoring

Redis

• Connection: redis client with connection pooling
• Operations: GET, SET, INCR, EXPIRE tests
• Performance: Response time validation
• Replication: Master-replica lag monitoring

Need More Detail?

For comprehensive documentation including:

• Advanced testing patterns (transactions, deadlock detection, connection pooling)
• Multi-database configurations (sharding, read replicas)
• Integration with monitoring systems (Datadog, Prometheus)
• Custom validation rules and migration testing
• Performance optimization strategies

Load: skills/smoke-test-database/REFERENCE.md (~15KB)