Caching Issues with ASP.NET Core 6 and Redis: Only Stale Data Retrieved
I've been struggling with this for a few days now and could really use some help. I'm currently facing a problem with caching in my ASP.NET Core 6 application that uses Redis for distributed caching. I've set up a simple caching mechanism for an API endpoint that retrieves user details, but I'm encountering an issue where only stale data seems to be returned from the cache, even after updating the underlying data in the database. Here’s the code I’m using to implement caching: ```csharp public class UserController : ControllerBase { private readonly IUserService _userService; private readonly IDistributedCache _cache; public UserController(IUserService userService, IDistributedCache cache) { _userService = userService; _cache = cache; } [HttpGet("/users/{id}")] public async Task<IActionResult> GetUser(int id) { var cacheKey = $"User-{id}"; var cachedUser = await _cache.GetStringAsync(cacheKey); if (cachedUser != null) { return Ok(JsonConvert.DeserializeObject<User>(cachedUser)); } var user = await _userService.GetUserByIdAsync(id); if (user == null) { return NotFound(); } await _cache.SetStringAsync(cacheKey, JsonConvert.SerializeObject(user), new DistributedCacheEntryOptions { AbsoluteExpirationRelativeToNow = TimeSpan.FromMinutes(5) }); return Ok(user); } } ``` The problem arises when I update user details in the database. I would expect the next API call to retrieve the updated user information from the database instead of the stale data from Redis. I have verified that the user information is being updated correctly in the database. In addition, I’ve tried manually invalidating the cache by calling `_cache.RemoveAsync(cacheKey)` after updating the user details, but it doesn’t seem to have any effect on the stale data issue either. The cache removal code executes without any exceptions, yet subsequent calls still return the stale data. When I check the Redis cache, it shows the correct key exists, but the data doesn't get updated as expected. I also made sure that my API calls for updating user details are properly reaching the database and returning successful responses. Is there something I'm missing in my caching implementation, or a common pitfall with Redis caching that could lead to this issue? Any help would be greatly appreciated. I'd really appreciate any guidance on this.