How to organize cache for external integration? What are the cache parameters?

For cache organization when integrating with external services, the following are usually used:

• Dedicated cache (e.g., Redis, Ehcache) for storing responses from external APIs.
• Local cache in the application memory for quick access to frequently used data.

Main cache parameters:

• TTL (Time To Live) — the lifetime of cached data after which it is considered outdated.
• Maximum size — limit on the number or volume of stored elements.
• Eviction policy — for example, LRU (Least Recently Used) for removing old elements.
• Update strategy — lazy loading (on demand) or proactive refresh (scheduled updates).
• Consistency — how often and in what manner the cache is synchronized with the source.

Example of using Spring Cache with Redis:

@Cacheable(value = "externalApiCache", key = "#id", unless = "#result == null")
public Data getDataFromExternalApi(String id) {
    // call to external service
}

In Redis configuration, you can set TTL for keys so that the cache is automatically refreshed.