01c69659c8
The TinyLFU test was failing for changes unrelated to anything in the tinyufo crate. This changes the test to stop that! What was occurring was expected behavior, so the test is what's changing instead of any internal logic. What was happening were hash collisions in the bloom filter used by the estimator. Instead of asserting that we'd always start counting from 0, we now allow for this in the test by `get()`ing first, then comparing relative values. For the final comparisons, we check that values are greater-than or equal-to their lower bound as determined by the number of `incr()`s we called on their keys. |
||
---|---|---|
.. | ||
benches | ||
src | ||
Cargo.toml | ||
LICENSE | ||
README.md |
TinyUFO
TinyUFO is a fast and efficient in-memory cache. It adopts the state-of-the-art S3-FIFO as well as TinyLFU algorithms to achieve high throughput and high hit ratio as the same time.
Usage
See docs
Performance Comparison
We compare TinyUFO with lru, the most commonly used cache algorithm and moka, another great cache library that implements TinyLFU.
Hit Ratio
The table below show the cache hit ratio of the compared algorithm under different size of cache, zipf=1.
cache size / total assets | TinyUFO | TinyUFO - LRU | TinyUFO - moka (TinyLFU) |
---|---|---|---|
0.5% | 45.26% | +14.21pp | -0.33pp |
1% | 52.35% | +13.19pp | +1.69pp |
5% | 68.89% | +10.14pp | +1.91pp |
10% | 75.98% | +8.39pp | +1.59pp |
25% | 85.34% | +5.39pp | +0.95pp |
Both TinyUFO and moka greatly improves hit ratio from lru. TinyUFO is the one better in this workload. This paper contains more thorough cache performance evaluations S3-FIFO, which TinyUFO varies from, against many caching algorithms under a variety of workloads.
Speed
The table below shows the number of operations performed per second for each cache library. The tests are performed using 8 threads on a x64 Linux desktop.
Setup | TinyUFO | LRU | moka |
---|---|---|---|
Pure read | 148.7 million ops | 7.0 million ops | 14.1 million ops |
Mixed read/write | 80.9 million ops | 6.8 million ops | 16.6 million ops |
Because of TinyUFO's lock-free design, it greatly outperforms the others.
Memory overhead
TinyUFO provides a compact mode to trade raw read speed for more memory efficiency. Whether the saving worthy the trade off depends on the actual size and the work load. For small in-memory assets, the saved memory means more things can be cached.
The table below show the memory allocation (in bytes) of the compared cache library under certain workloads to store zero-sized assets.
cache size | TinyUFO | TinyUFO compact | LRU | moka |
---|---|---|---|---|
100 | 39,409 | 19,000 | 9,408 | 354,376 |
1000 | 236,053 | 86,352 | 128,512 | 535,888 |
10000 | 2,290,635 | 766,024 | 1,075,648 | 2,489,088 |