Ehcache 3.x support

[lesserwhirls]

Ehcache 2.x reached end-of-life as of September 2023. I took a pass at upgrading the codebase to use Ehcache 3.x, but I hit a roadblock. Ehcache 2 provided a lot of flexibility in terms of the cache configuration that is not available in Ehcache 3. While I could migrate the domainMapperCache and meshDatasetCaches without too much trouble, the featureCache requires much more thought and likely some critical design choices that I'm uncertain about. Has anyone else looked into migrating from Ehcache 2 to Ehcache 3?

[zhenghuizhh]

Hi, is there any update for this issue? Thanks.

[ben-manes]

When you upgrade, please adjust your cache keys by using a strong hashCode() function, like murmur3’s finalizer. This is to avoid a severe degradation which impacts large caches due to O(n) eviction (it may be fine if small caches). The link provides details of why this occurs and explains the mitigation. For example your Domain2DMapperCacheKey’s hashCode is weak like the sample scenarios demonstrates so if the cache is large you may observe this surprising behavior.

[lesserwhirls]

Thank you for the heads-up @ben-manes!