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I’m shocked that Rust only gave you a 2X improvement over Python (I’ve rewritten a handful of Python services to Go and typically see 100-1000X improvement). Wh

I’m shocked that Rust only gave you a 2X improvement over Python (I’ve rewritten a handful of Python services to Go and typically see 100-1000X improvement). What is the bottleneck? Was scaling horizontally an option?

tech2 8y ago
I suspect the reason it's not faster is one of the following: 1. backend DB at its query limit 2. this is basically my first rust program and I've done something stupid 3. ab/wrk aren't scaling properly either (I know, not likely, but worth considering) when I'm testing it 4. bandwidth/IO limits on the AWS instance types I'm running this on There are other possibilities too I guess. I was mostly doing this as a means to learn Rust though, I'd only go live with it once I had decent tests and everything else.
- the_duke 8y ago
  What web framework are you using? Are you using a database? If so, which one? Are you using a cache like Redis? I agree that a 2x speedup is a terribly low for a Python to Rust rewrite and shows that Python is unlikely to be the relevant bottleneck here.
  - tech2 8y ago
    actix/r2d2 on the Rust side (I haven't worked out bb8 yet), aiohttp/uvloop/asyncpg/gunicorn on the Python side (Postgres for the DB). This kinda _is_ the cache at present, it's a distillation of a lot of other data into a given form. Rust's async story re: databases still looks a little up-in-the-air right now from an outside perspective though, so I guess I'll wait and see how it pans out. It's definitely a work in progress and I didn't expect this much interest in my offhand "I tried Rust even though I couldn't see myself using it for real, but..." comment.
  - weberc2 8y ago
    > What web framework are you using? I can't imagine the web framework is the bottleneck...
    - the_duke 8y ago
      It might be because if it's a tokio-core based one OP might be blocking the event loop too much.
vkjv 8y ago
Interestingly, I was able to get an amazing speed improvement without going completely to Rust. I didn't want to port APM code as well, so I kept node.js/express for routing. Very simple middleware that immediately passed the request and body buffer to Rust for handling. Rust returned a buffer back to express for sending the response. It's easily able to hit 100k RPM on a single instance before hitting a CPU bottleneck in the Rust code (validating an RSA signature). It only needs to handle 90k RPM total.

tech2 8y ago

I suspect the reason it's not faster is one of the following: 1. backend DB at its query limit 2. this is basically my first rust program and I've done something stupid 3. ab/wrk aren't scaling properly either (I know, not likely, but worth considering) when I'm testing it 4. bandwidth/IO limits on the AWS instance types I'm running this on There are other possibilities too I guess. I was mostly doing this as a means to learn Rust though, I'd only go live with it once I had decent tests and everything else.

the_duke 8y ago
What web framework are you using? Are you using a database? If so, which one? Are you using a cache like Redis? I agree that a 2x speedup is a terribly low for a Python to Rust rewrite and shows that Python is unlikely to be the relevant bottleneck here.
- tech2 8y ago
  actix/r2d2 on the Rust side (I haven't worked out bb8 yet), aiohttp/uvloop/asyncpg/gunicorn on the Python side (Postgres for the DB). This kinda _is_ the cache at present, it's a distillation of a lot of other data into a given form. Rust's async story re: databases still looks a little up-in-the-air right now from an outside perspective though, so I guess I'll wait and see how it pans out. It's definitely a work in progress and I didn't expect this much interest in my offhand "I tried Rust even though I couldn't see myself using it for real, but..." comment.
- weberc2 8y ago
  > What web framework are you using? I can't imagine the web framework is the bottleneck...
  - the_duke 8y ago
    It might be because if it's a tokio-core based one OP might be blocking the event loop too much.

vkjv 8y ago

Interestingly, I was able to get an amazing speed improvement without going completely to Rust. I didn't want to port APM code as well, so I kept node.js/express for routing. Very simple middleware that immediately passed the request and body buffer to Rust for handling. Rust returned a buffer back to express for sending the response. It's easily able to hit 100k RPM on a single instance before hitting a CPU bottleneck in the Rust code (validating an RSA signature). It only needs to handle 90k RPM total.