What are you using for Distributed Caching in web farms running ASP.NET?

Question

I am curious as to what others are using in this situation. I know a couple of the options that are out there like a memcached port or ScaleOutSoftware. The memcached ports don't seem to be actively worked on (correct me if I'm wrong). ScaleOutSoftware is too expensive for me (I don't doubt it is worth it). This is not to say that I don't want to hear about people using memcached or ScaleOutSoftware. I'm just stating what I "know" at this point.

So my question is basically this: for those of you ACTIVELY using distributed caching, what are you using, are you happy with it, and what should I look out for?

I am moving to two servers very soon...both will be at the same location. I use caching fairly heavily (but carefully) to reduce the load on my database server.

Edit: I downloaded Scaleout Software's solution. I've coded for it and it seems to work real well. I just have to decide if my wallet will part with the cash for it. :) Anyone have experiences good or bad with ScaleoutSoftware?

Edit Again: It's been a little while since I asked this? Any more thoughts on it? We ended up buying the solution from ScaleOutSoftware and have been happy with it, but I'm curious what others are doing.

Answer 1

We are using the memcached port for Windows and we are very pleased with it. The enyim.com memcached client API is great and easy to work with. It's also open source, which is a big advantage, if you ask me.

We are now using this setup in a production web-app and it has helped a lot in improving its performance.

Answer 2

Microsoft has a product pending code-named Velocity. It's still in CTP, and is moving slowly, but looks like it will be pretty good. We'll be beating it up in the near future to see how it handles what we want it to do (> 2 million read/writes per hour). Will post back with results.

Answer 3

We use memcached with the enyim library in a production environment (www.funda.nl). Works fine, very pleased with it, but we did notice a substantial raise in CPU use on the clients. Presumably due to the serializing/deserializing going on. We do around 1000 reads per second.

Answer 4

There's a great .NET wrapper/port found here on Codeplex. Awesomesauce!

Answer 5

We're currently using an incredibly simple cache that I wrote in a couple of hours, based on re-hosting the ASP.NET cache in a Windows Service (more info and source code here). I won't pretend it's anywhere near as optimised as something like Memcached but we were just looking for something simple and free until Velocity came along, and it's held up extremely well even under fairly heavy load.

It comes down to our personal preference for core components - i.e. ones that affect whether the site is available or not - that they are either (a) supported by a vendor with a history of rapid and high quality support, or (b) written by us so that if something goes wrong we can fix it quickly. Open source is all well and good, and indeed we do use some OSS, but if your site is offline then unfortunately newsgroups et al don't have a 1 hour SLA, and just because it's OSS doesn't mean you have the necessary understanding or ability to fix it yourself.

Answer 6

There is a 100% native .NET, well documented open source (LGPL) project called Shared Cache. Looks like it is not yet mentioned on SO, but it's promising and should be able to do what most people expect from a distributed cache. It even supports different strategies like distributed or replicated caching etc.

I will update this post with more details as soon as I had a chance to try it on a real project.