Introduction

Sets a short TTL on string keys matching a pattern in a Redis database to force them to expire, simulating sudden cache invalidation. Non-string keys (hashes, lists, sets, etc.) are skipped. When the attack ends, expired keys can optionally be restored with their original values and TTLs.

This action targets Redis databases (not instances). For instance-level memory pressure, use Limit MaxMemory instead. For connection-level faults, use Exhaust Connections.

Use Cases

• Simulate sudden cache invalidation to test cache rebuild performance and thundering-herd resilience.
• Verify session expiration handling by expiring session keys and observing application behavior.
• Test that the application gracefully handles cache misses without degraded user experience.

Parameters

Parameter	Description	Default
Duration	How long the attack should last.	60s
Pattern	Key pattern to match (e.g., session:*, cache:*). Uses Redis SCAN glob-style matching. Only string keys are affected; non-string keys are skipped.	steadybit-test:*
TTL	Time-to-live to set on matched keys. Keys expire after this duration.	5s
Max Keys	Maximum number of keys to affect. Set to 0 for unlimited. Use this to limit blast radius in production.	100
Restore On Stop	Restore expired keys with their original values and TTLs when the attack ends. Strongly recommended to prevent data loss.	true