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As a fan of Rust, this seems like the perfect application domain for "fearless concurrency". Having gone through the bowels of a few different connection pool i

As a fan of Rust, this seems like the perfect application domain for "fearless concurrency". Having gone through the bowels of a few different connection pool implementations in various languages (because they had bugs in production), I can tell you the concurrency management becomes extremely difficult to reason about as the feature complexity increases. I think you're making a good bet that offloading a good chunk of that to the compiler will improve your ability to iterate in the future. GoLang seems like the language du jour, but I think this post [1] really illustrates how powerful it can be when you have a compiler that handles so much more for you. It's not just about performance. Deadlock detection and a robust compile time set of error checks are huge wins over looser languages. 1: https://fasterthanli.me/articles/some-mistakes-rust-doesnt-catch https://fasterthanli.me/articles/some-mistakes-rust-doesnt-c...

montanalow 5y ago
This is actually pretty amazing. I wouldn't normally trust a single author implemented project to sit between my application and my database, since that is a rather critical single point of failure. However, a grep that fails to find `unsafe` in a rust code base lets me know that this code is in fact pretty safe[1]. I don't need to trust the author, as much as I trust the Rust core team, and LLVM. Since I can see basic functionality exercised in the test suites, and trust that Rust has validated its more general correctness, this gives me more confidence in your project than I would historically expect to be able to gather in such a short amount of time. 1: https://github.com/levkk/pgcat/search?q=unsafe https://github.com/levkk/pgcat/search?q=unsafe
- Thaxll 5y ago
  Being in Rust or not the code has 0 tests, write arbitrary bytes, hard code values etc ... looks like more a PoC project that something that going to replace pgbouncer any time soon.
  - mmontagna9 5y ago
    Yep the readme is pretty clear it's a POC "Alpha: don't use in production just yet." That said I've struggled with more than my fair share of pgbouncer misconfigurations and outright bugs. I personally would love a simpler (harder to misconfigure) and less buggy alternative.
  - levkk 5y ago
    It's definitely a PoC. I started it two weeks ago. Overall I've been super happy with Rust because it was a great safety harness and it gave me a fast concurrent program. PgBouncer implements this in about 30k lines of C, while I managed to get 80% of the way and then some in less than 1k. As for tests, it's covered with pgbench, python (psycopg2), ruby (pg / active record gems), psql and a couple inline tests for trivial things like config. As for bytes and hardcoded ints...give pgbouncer's and postgres' source code a look :).
- hnarn 5y ago
  > a grep that fails to find `unsafe` in a rust code base lets me know that this code is in fact pretty safe This statement does not make any sense. That, or we have vastly different definitions of what “safe” means.
  - zild3d 5y ago
    yeah maybe it safely deletes all your tables at midnight
    - deleted 5y ago
      [deleted]
    - politician 5y ago
      The “unsafe” keyword in Rust is a source of perpetual oblivious overconfidence. It should’ve been called something that befits it’s actual narrow scope (`disableStongTypeChecks` or some such) but that ship has sailed.
      - remram 5y ago
        "unsafe" is pretty clear: the block/function is not safe, that doesn't mean the rest is safe. I suppose it might have been better named as "asserted", "assumed_safe", or "manually_checked", but that's much more verbose and not necessarily clearer.
        politician 5y ago
        These blocks are supposed to be rare, so a more verbose keyword isn't a problem. It would be better to be precise here and avoid a concept so general as safety.
  - montanalow 5y ago
    When you remove the context around statements (thread about rust concurrency), it's easy to make a statement into overblown nonsense. You may be interested in the broader analysis contained in the link from parent comment, about the type of safety being discussed in this thread, or you may not.

montanalow 5y ago

This is actually pretty amazing. I wouldn't normally trust a single author implemented project to sit between my application and my database, since that is a rather critical single point of failure. However, a grep that fails to find `unsafe` in a rust code base lets me know that this code is in fact pretty safe[1]. I don't need to trust the author, as much as I trust the Rust core team, and LLVM. Since I can see basic functionality exercised in the test suites, and trust that Rust has validated its more general correctness, this gives me more confidence in your project than I would historically expect to be able to gather in such a short amount of time. 1: https://github.com/levkk/pgcat/search?q=unsafe https://github.com/levkk/pgcat/search?q=unsafe

Thaxll 5y ago
Being in Rust or not the code has 0 tests, write arbitrary bytes, hard code values etc ... looks like more a PoC project that something that going to replace pgbouncer any time soon.
- mmontagna9 5y ago
  Yep the readme is pretty clear it's a POC "Alpha: don't use in production just yet." That said I've struggled with more than my fair share of pgbouncer misconfigurations and outright bugs. I personally would love a simpler (harder to misconfigure) and less buggy alternative.
- levkk 5y ago
  It's definitely a PoC. I started it two weeks ago. Overall I've been super happy with Rust because it was a great safety harness and it gave me a fast concurrent program. PgBouncer implements this in about 30k lines of C, while I managed to get 80% of the way and then some in less than 1k. As for tests, it's covered with pgbench, python (psycopg2), ruby (pg / active record gems), psql and a couple inline tests for trivial things like config. As for bytes and hardcoded ints...give pgbouncer's and postgres' source code a look :).
hnarn 5y ago
> a grep that fails to find `unsafe` in a rust code base lets me know that this code is in fact pretty safe This statement does not make any sense. That, or we have vastly different definitions of what “safe” means.
- zild3d 5y ago
  yeah maybe it safely deletes all your tables at midnight
  - deleted 5y ago
    [deleted]
  - politician 5y ago
    The “unsafe” keyword in Rust is a source of perpetual oblivious overconfidence. It should’ve been called something that befits it’s actual narrow scope (`disableStongTypeChecks` or some such) but that ship has sailed.
    - remram 5y ago
      "unsafe" is pretty clear: the block/function is not safe, that doesn't mean the rest is safe. I suppose it might have been better named as "asserted", "assumed_safe", or "manually_checked", but that's much more verbose and not necessarily clearer.
      - politician 5y ago
        These blocks are supposed to be rare, so a more verbose keyword isn't a problem. It would be better to be precise here and avoid a concept so general as safety.
- montanalow 5y ago
  When you remove the context around statements (thread about rust concurrency), it's easy to make a statement into overblown nonsense. You may be interested in the broader analysis contained in the link from parent comment, about the type of safety being discussed in this thread, or you may not.