CDN here works as a cache with limited memory, data invalidation will be done according to some strategy — I would assume LRU as a standard invalidation strategy. What do you think about using it here?

Using the LRU (Least Recently Used) strategy for cache invalidation in CDN is a standard and effective approach, especially when memory is limited. LRU automatically removes the least recently used objects from the cache, increasing the likelihood that the cache contains relevant and demanded data.

Advantages of LRU:

• Simple to implement and understand.
• Well-suited for access locality scenarios.
• Allows efficient use of limited memory.

However, it is important to consider the specifics of the load and access patterns. For example, if some data is rarely requested but critical, hybrid strategies or priorities can be considered.

Overall, for a CDN with limited memory, LRU is a reasonable default choice.