Category |
Method |
---|---|
Big key |
Split big keys. Scenarios:
|
Store big keys on other storage media. If a big key cannot be split, it is not suitable to be stored in Redis. You can store it on other storage media, and delete the big key from Redis. CAUTION:
Do not use the DEL command to delete big keys. Otherwise, Redis may be blocked or even a master/standby switchover may occur. |
|
Hot key |
Use the client cache or local cache. If you know what keys are frequently used, you can design a two-level cache architecture (client/local cache and remote Redis). Frequently used data is obtained from the local cache first. The local cache and remote cache are updated with data writes at the same time. In this way, the read pressure on frequently accessed data can be separated. This method is costly because it requires changes to the client architecture and code. |
Design a circuit breaker or degradation mechanism. Hot keys can easily result in cache breakdown. During peak hours, requests are passed through to the backend database, causing service avalanche. To ensure availability, the system must have a circuit breaker or degradation mechanism to limit the traffic and degrade services if breakdown occurs. |