theine-go VS sosp23-s3fifo

In fact, lock-free queues have several problems at once, which prompted me to give up on them almost immediately.

1. Yes, S3-FIFO can be implemented using lock-free queues, but the problem is that each write to a filled cache using this design will cause a large number of additional atomic operations not friendly to the processor's cache, while bp-wrapper on the contrary amortizes this load. And reading with frequency update on hot entries can have a bad effect on performance. In many ways this is exactly what the last posts in my discussion with Ben are about (not really about this, but the current problem with otter read speed is caused by a similar problem). https://github.com/Yiling-J/theine-go/issues/29#issuecomment...

2. But the main problem for me is not even that. Lock-free queues work fine as long as you only need to support Get and Set operations, but as soon as you want to add features to your cache, the complexity of the implementation starts to increase, and some features are very hard to add to such a structure. Also, improving the eviction policy is under a big question mark, because not only do you have to think about how to improve the eviction policy, but also how to avoid locks while doing so or how not to slow down the implementation with your improvements. BP-Wrapper has no such problems at all, allows you to use any eviction policy and focus on improving different parts of your cache independently of each other.

CacheStore is an interface so I can use a different local cache instead? For example my adaptive cache package Theine, I think the hit ratio will be much higer than the default LRU one.

0.2.0 add removal callback and loading cache(with thundering herd protection), take a look: https://github.com/Yiling-J/theine-go

Theine: https://github.com/Yiling-J/theine-go

We observed that quick demotion[2] is important to achieve a low miss ratio in modern cache workloads, and existing algorithms such as TinyLFU and LIRS have lower miss ratios because of the small 1% window they use. This motivated us to design S3-FIFO, which uses simple FIFO queues to achieve low miss ratios. It is true that compared to state-of-the-art, S3-FIFO does not use any fancy techniques, but this does not mean it has bad performance.

In our large-scale evaluations, we found that the fancy techniques in LIRS, ARC, and TinyLFU can sometimes increase the miss ratio. But simple FIFO queues are more robust. However, *it is not true that S3-FIFO is better on every trace*.

* Note that some of the S3-FIFO results in Otter's repo are not updated and have an implementation bug, and we are working with the owner to update them.

[1] https://github.com/Thesys-lab/sosp23-s3fifo?tab=readme-ov-fi...