Handling Dynamic Expiration of Cached Data in ASP.NET Core with IMemoryCache
Hey everyone, I'm running into an issue that's driving me crazy... I'm learning this framework and I'm converting an old project and I'm working on a personal project and I'm currently working on an ASP.NET Core 6 application where I need to implement caching using `IMemoryCache`... My requirement is to have cached items that expire dynamically based on a specific condition. For example, I want to set the cache to expire an item if a certain value exceeds a threshold, but I also want it to be removed after a fixed period if the condition isn't met. I've tried using `MemoryCacheEntryOptions` to set the absolute expiration time, but I need to figure out how to incorporate the dynamic expiration logic based on my condition. Here's a simplified version of what I've implemented so far: ```csharp public class MyService { private readonly IMemoryCache _cache; public MyService(IMemoryCache cache) { _cache = cache; } public void CacheData(string key, int value) { var options = new MemoryCacheEntryOptions() .SetAbsoluteExpiration(TimeSpan.FromMinutes(5)); // Fixed expiration // Check condition for dynamic expiration if (value > 100) { options.SetSlidingExpiration(TimeSpan.FromMinutes(10)); // Extended if condition met } _cache.Set(key, value, options); } } ``` However, what I'm observing is that the cache is not expiring as expected. Specifically, when I set the sliding expiration based on the value exceeding 100, the cache never seems to expire afterward, even if the value drops below that threshold. The fixed expiration is working fine, but the dynamic part seems to interfere with the cache lifetime. I've also experimented with using `PostEvictionCallback` to see if I can log or process items upon eviction, but that hasn't helped me solve the scenario. I’m not sure if I’m misusing `IMemoryCache` or if there’s a better pattern to achieve this dynamic caching behavior. Any help or insights on the right approach would be appreciated! I'm coming from a different tech stack and learning C#. This issue appeared after updating to C# 3.11.