I am reading the Elixir in Action book and testing ETS page cache implementation (10.2.2) on Windows 10 Pro (i7-5820K 3.30GHz, 6 cores). I got the following results:
As you can see in concurrent case call the difference is HUGE! 80 thousand vs 10 million requests per second. I am trying to find an explanation and curious if anybody else (who read the book) tested it and what were the results?
It appears you’re running examples from the first edition. For various reasons, these are obsolete.
My main OS is macos, but I’ve just tried the 2nd edition examples (the 2nd-edition branch) on Windows 10, quad core machine, Elixir 1.6 and Erlang 20.2. Here’s what I’ve got:
non ETS:
mix run -e "Bench.run(KeyValue)"
245682 operations/sec
mix run -e "Bench.run(KeyValue, concurrency: 100)"
317935 operations/sec
ETS:
mix run -e "Bench.run(EtsKeyValue)"
1828488 operations/sec
mix run -e "Bench.run(EtsKeyValue, concurrency: 100)"
3575259 operations/sec
For comparison, here’s what I’ve got on my macbook:
non ETS:
mix run -e "Bench.run(KeyValue)"
621003 operations/sec
mix run -e "Bench.run(KeyValue, concurrency: 1000)"
325055 operations/sec
ETS:
mix run -e "Bench.run(EtsKeyValue)"
3576332 operations/sec
mix run -e "Bench.run(EtsKeyValue, concurrency: 1000, num_updates: 100)"
16993927 operations/sec
There are clearly some differences between Windows/macos, which I currently can’t explain. One part of the reason could lie in the fact that the benchmark is synthetic, simplified, and originally performed on my macos machine. Regardless, the two main points hold across different OSes:
ETS implementation is much faster than non-ETS
ETS implementation scales better than non-ETS
Either way, your results are quite strange, since performance degrades significantly with increased concurrency. I wonder if your Erlang installation is taking advantage of multiple cores at all? What’s the result of System.schedulers and System.schedulers_online?