I like it when they add things to .Net that ARE actually useful instead of just pretty.

we've spent quite some time to kind of build those features on top of IDistributedCache so I am glad it is now a built in feature. no idea why it is a class tough...

Looks great, but I _really_ dislike the magic registration, when HybridCache detects automatically what type of distributed cache is registered. If you know, sure, easy, however if you find yourself in a project without that knowledge, there is "no breadcrumb" to lead you on to what is really happening. Feels like unnecessary bar rising for less experienced developers or less lucky to be around when this feature is being advertised... Still, looking forward to take it for a spin :)

This is amazing, just what I needed!

This is the best ever thing Microsoft has released in the past 2 years. Only if this was released like 6 months ago when I needed something similar. Was a pain in the ... to build this kind functionality

Awesome video! Thanks for that!

It's cloudy, what a surprise

Awesome feature and video, thank you! The only downside that it's in .NET 9 and not earlier :)

love it!

thanks

Very nice!

Great video Nick! With Hybrid Cache you also use your own custom serializers which means that one does not have to rely only on standard system text json or newtonsoft json providers. 🚀

That's actually quite nice. I think that's going to be a very useful tool in the future to consider.

Very interesting

I think that's an awesome one! Looking into the docs/options, it's not clear to me whether it behaves in a multi-layer manner, or whether it is an option that you can switch on. I.e., if I want the cache to first try to grab a value from the local (IMemoryCache) cache, and then if not found - go to the shared (IDistributed) one, and once found or refreshed - update the local cache entry back. I used to build something like this to reduce some redis calls. Of course this comes with a cost of extra delay for the updated value to get it to the consumers, however, if configured the TTL properly for both shared and local caches, might be worth it for some scenarios. So, is this now achievable out-of-the-box with the new HybridCache thing?

They should just bring over fusion cache. Tagging is a nice feature.

Nice feature! I am currently using the NuGet package LazyCache instead of the plain memory cache, primarily for the Stampede-protection but also for a feature that immediatly evicts items from the cache on expiration. Is that something HybridCache supports?

FINALLY THEY ADDED A TAG TO CACHE ITEMS, GOD BLESS YOU MICROSOFT

Does the HybridCache support just returning the last cached value while the cache is being updated? That behavior is really handy for performance critical services like whisperers where you don't want to unnecessarily block multiple clients when the cache is stale.

FYI, the library LazyCache does the same as HybridCache. Better to use HybridCache going forward but wanted to set the record straight that this functionality has been available for years.

Ok, HybridCache seems like a good addition to the collection of cache implementations. But one thing that I don't like about it is that it don't have a factory solution where I can specify a cache create / refresh method centrally. Much like the IConfiguration provider solution. The problem arises when I want to reuse the same cached value in multiple places. I then have to specify the factory in multiple places...

making it thread safe is really nice, one thing I'm concerned about here is bugs introduced by the duality usage option. for example if somehow you didn't register the redis cache you won't know about it until the memory leak start to happen or cache miss in case of multiple instances. it would be nice if there is a way to make it a requirement for redis cache to be registered in some cases. I know you can do this manually but it would be nice if it can be implemented in the options setup in AddHybridCache directly.

As I understand it doesn't lock across multiple instances. In case of multiple instances making the same call all of the instances will make the same call to the weather API. So if you have 10 instances of the same service and a very loaded environment there still might be several simultaneous calls.

Can you do a video about how to debug applications that run on docker/kubernetis?

Can you clarify? If a different request for weather comes in... does it still block? Or is the blocking purely based upon the cache key?

1) Synchronization of requests for any memory cache can be handled easily by inserting a Lazy. The Lazy minimizes (or even eliminates) the chance of opportunistic concurrency, and the Task is the actual request that gets made and shared. Sure, you have to do some smart eviction if either of those fail, but IMO, I think this kind of operation should have be built in to (or provided as an extension) any memory cache. 2) I would always have a short term expiry in memory cache for anything that is cache-able. Ideally tuned with a short term sliding expiry that still honors an absolute. Then of course, the distributed cache API would be the next layer that the in memory cache calls to. 3) Either way, each cache layer should have an option to use pessimistic concurrency. AKA "stampede protection" should be an option for both, and IMO, its should be the default.

I was dealing with this problem last week. Excited for .net 10 when I can use it lol

its a christmas miracle!

I think Microsoft has a long way to go with Hybrid caches. But yet, its a very nice start. Basically, what hybrid cache is, it will leverage both in-memory and distributed cache at the same time but in a way that the request does not have to travel to the distributed cache in order to reduce latency. The idea is, at the time of storing a record, it will store the data into the in-memory cache and send a message asynchronously to any kind of bus (i.e. redis bus) indicating that a WeatherCached event has occurred. And on the other side, the same instance will subscribe to that event and store that data into the distributed cache. if other instances of the same app/different microservice/a different module that is consuming that same event from the same channel will store it in their own in-memory cache. this way Hybrid Caching helps us leveraging both in-memory cache and distributed cache at the same time and the incoming requests to web/api server do not need to travel over the network to get the data because its already available in-memory.

IMHO: HybridCache looks like the way moving forward, but please also mark IMemoryCache and IDistributedCache [Obsolete] and whatever jargon made into BCL with .NET 9 Release and completely remove both of these APIs in .NET 10. The BCL Team may consider using the [Obsolete] attribute more aggressively between alternating .NET Releases - keep the BCL clean and tidy. PLEASE!!!

How is this multi-call protection works? So if I call for weather of London twice, the second call is waiting. But if I call with othe city, do both calls go through to the openweather server?

My issue here is that we are cache:ing null for N minutes if we get a bad-request... but assuming you handle that, I think this new cache could be very helpful - especially with db-lookups or external API-calls

Which IDE and CLI do you use please ?

Did they just embrace, extend and extinguish FusionCache? 😂

One more solution with implicit dependency. There is no declaration that says - HybridCache functionality depends on Redis. MS need to change this as it done in many cases already.

I hate to use the C word, caching has usually just caused me pain but maybe I will finally have to concede now that I am building something with genuine millisecond speed implications. BTW this works especially well with multiple pods where you don't want to worry about each pod having totally different speeds! Great video as I am getting into k8s ❤

Yay I can get ride of all the semaphoreslims

Syntactic sugar for ConcurrentDictionary. Nice!

Does in have "automatic" population after some time like old .NET frameworks MemoryCache had with its callbacks?

I manually implemented something similar to HybridCache, but it was impossible to do proper Cache Invalidation. You can clear the distributed cache, you can clear the current instance's local cache, but you can't clear a different instance's local cache. This meant we had to use a plain distributed cache if the use case required cache invalidation. Fortunately most use cases don't need it.

Since IMemoryCache came out I've been wishing they just had an ICache type with MemoryCache and DistributedCache implementations (and now HybridCache). Would have been a lot cleaner and simpler that way.

Will it use in-memory if the distributed cache fails?

That's weird, I don't see any course abut Azure stuff like cosmos db or azure function or blob storage or azure DevOps in dometrain , I will be happy if you add them , thanks

Have redis changed their license and no longer open source? If so what are some good alternatives?

12:00 Distributed cache*

What happen if, during the GetCreate cache, the API request fails? Will it caches the bad response or will it ignores it? I think this is quite common case, where normally you would end up with all incoming requests receive cached bad response

Btw, could you make a video on Garnet?

Is this code avaiable on github?

Confused .NET 9 preview 4 is available at the moment, how can you be using .NET 9 preview 5?

Does this work if you hit multiple instances of the application? or would each of them run the request to the weather api?

RemoveByTag distributed is killer, finally.

I wonder if they made the HybridCache an abstract class for the same reasons they're recommending you use collection classes for performance. You see that more and more. If that is the case I would agree with it being an abstract class. Too bad indeed they made another package. I hope they remove IMemoryCache to prevent any confusion. Seems like a simple upgrade tool could fix this easily when going from .NET 8 to 9. They should promote the tool for that more.

Anyone knows what is the Nick's preferred Redis interface over IDistributedCache?

This is interesting. But can you make sure that all the code is shown on the screen. Some of it was cut off.

Why isn't there a Get method. What should I do to just check is something in cache?

🎯 Key Takeaways for quick navigation: 00:00 *🌐 Introduction to Caching in .NET 9* - Explanation of the need to replace the ID distributed cache interface - Introduction to the new caching mechanism in .NET 9 - Comparison between the in-memory cache and the new caching mechanism 05:15 *🔍 Issues with Existing Caching Methods* - Challenges with stampedes in caching operations - Limitations of the ID distributed cache interface - Lack of features like tag-based eviction and instrumentation in current caching methods 08:27 *💡 Introduction to Hybrid Cache in .NET 9* - Overview of the new Hybrid Cache introduced in .NET 9 - Benefits of using the Hybrid Cache over the ID distributed cache and in-memory cache - Simplification of caching operations with the Hybrid Cache solution Made with HARPA AI

Why did they choose to make it an abstract class instead of interface?

Where can I find the source code for this video DEMO? Thank you.

Don't like the abstract approach. The benefit of an interface is simply that you choose how to implement all methods; in an abstract class there might be additional methods you can't overwrite or there are constructors expecting something. So there is clear drawbacks but I can't imagine any real benefits (I think even the calling speed of interface methods and v-calls is the same). What I really never like about IMemoryCache is that there's basically no namespace. Tags are a nice workaround for cleanup but it doesn't solve the $"{namespace}:{id}" issue.

I use IOutputCache with an extensions to support redis, so in this scenario between hybrid and ioutputcache you can go either way, however i heavly tested the ioutputcatch and seems to be pretty fast too!

Can we get this somehow in .net 8 too?

So this in NET9 is replacing the "Microsoft.Extensions.Caching.Memory" ?

A lack of common interface seemed weird to me, having a fake distributed cache for testing was odd.

I don't know who has built this framework, congratulations and thanks 👍

I like this video because it's flaming London

This is why you shouldn't directly code to the M$ interfaces. You should always wrap them within your own interface and call the MS implementation from your own implementation so you can swap them out at will without changing your client code.

Oh caching...

I want to use Ai chatbots and see which ones are best for .Net? like problem solving, code analysis ect

I don't get how this is new tech, thats nothing new. I'm using 2 tiered cache including proper event driven cache invalidation for 10+ years in .NET. It is great they finally include something like this into their caching abstraction, but new tech? Bro, na, not even close :p Also, you suggest that everyone should replace the IDistributedCache interface with this feature? That's risky. Unless you know exactly what you are doing and why you need it, don't. Caching this way is more complex and has other challenges, so if you have to rely on cache validity and never expect stale data, don't use this ever. If you do not know what I'm talking about, don't use it either.

Cloudy in London... Who would have thought?

Microsoft named a built-in cache extension after a specific company, StackExchange? Very unusual.

I'm the one who always looks for js framework alternatives, basically i don't like blazor because it has over engineering and it's not compatible for MCV, MVC which is real flex of web development, really looking forward hydro

well then, how I do I know MS didn't steal my code from Github?

MS SHOULD SLOW DOWN WITH NEW .NET VERSIONS!! EVERY 2 WEEKS NEW VERSIO