Data Integrity

Keeping state correct through concurrency, failure and schema change.

4 concepts · 165 minutes

• IdempotencyMaking 'do it again' safe — the single idea that separates reliable distributed code from hope.
• Schema MigrationsChanging a schema under live traffic without taking the site down.
• Transactions & ACIDAll or nothing — plus the isolation levels that decide which anomalies you're allowing.
• Race ConditionsTwo things interleaving in an order you never tested — the bug class that only shows up in production.