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Have you ever had to deal with tail latency due to memory pressure on web or backend services? Command-line tools are also ideal for Rust because startup perfo

Have you ever had to deal with tail latency due to memory pressure on web or backend services? Command-line tools are also ideal for Rust because startup performance matters a lot there.

pjmlp 6y ago
Yes, writing distributed systems since 1999. What was done in C, C++ and Tcl, I nowadays use Java and .NET languages. If we really need something low level that either Java or .NET cannot offer, a native library for a specific component will do, no need to throw the whole thing away and do one of those rewrite blog posts.
- howinteresting 6y ago
  Tail latency due to memory pressure tends to be inherent to the nature of garbage collected languages with mutable state. This is not an issue if you have more RAM then the system needs, but often RAM is extremely scarce.
  - pjmlp 6y ago
    Garbage collected languages also offer means to do C like memory allocation, it is matter to use the language features and FFI capabilities, but many just learn their stacks superficially and follow Rewrite in X trendy blog posts instead.
    - howinteresting 6y ago
      There is a very big difference between what particular environments offer in theory (yes, you can write object pools in Java and many high-performance projects use them) and the situation in practice (there are people who spend a large chunk of their professional careers doing JVM tuning). Idiomatic Rust avoids the situations which require JVM tuning experts. You can write a Rust service, put it into production and tail latency is very likely not going to be a problem at all. Now you may decide that needing the occasional services of a JVM tuning expert is better overall than ownership concerns being pervasive throughout a codebase, depending on the specifics. But do accept that the trade-off exists.
      - pjmlp 6y ago
        Only when speaking about kernel code, drivers, and similar scenarios. You are the one focusing in Java, and in your answer proved exactly my point of knowing stacks superficially. Object pools aren't the only way to reduce memory footprint in Java. A bit of FFI into host OS syscalls and it is done, or a tiny high performance native library for a custom data structures and ready for the races. No need to throw away 25 years of tooling and libraries. Then we can move into languages that offer exactly the same features as C++, like D, Nim, Swift, Eiffel, Ada.
        howinteresting 6y ago
        I've written three of those sorts of native libraries before, and it's just awfully inconvenient compared to just using Rust to be honest.

Have you ever had to deal with tail latency due to memory pressure on web or backend services? Command-line tools are also ideal for Rust because startup performance matters a lot there.

pjmlp 6y ago

Yes, writing distributed systems since 1999. What was done in C, C++ and Tcl, I nowadays use Java and .NET languages. If we really need something low level that either Java or .NET cannot offer, a native library for a specific component will do, no need to throw the whole thing away and do one of those rewrite blog posts.

howinteresting 6y ago
Tail latency due to memory pressure tends to be inherent to the nature of garbage collected languages with mutable state. This is not an issue if you have more RAM then the system needs, but often RAM is extremely scarce.
- pjmlp 6y ago
  Garbage collected languages also offer means to do C like memory allocation, it is matter to use the language features and FFI capabilities, but many just learn their stacks superficially and follow Rewrite in X trendy blog posts instead.
  - howinteresting 6y ago
    There is a very big difference between what particular environments offer in theory (yes, you can write object pools in Java and many high-performance projects use them) and the situation in practice (there are people who spend a large chunk of their professional careers doing JVM tuning). Idiomatic Rust avoids the situations which require JVM tuning experts. You can write a Rust service, put it into production and tail latency is very likely not going to be a problem at all. Now you may decide that needing the occasional services of a JVM tuning expert is better overall than ownership concerns being pervasive throughout a codebase, depending on the specifics. But do accept that the trade-off exists.
    - pjmlp 6y ago
      Only when speaking about kernel code, drivers, and similar scenarios. You are the one focusing in Java, and in your answer proved exactly my point of knowing stacks superficially. Object pools aren't the only way to reduce memory footprint in Java. A bit of FFI into host OS syscalls and it is done, or a tiny high performance native library for a custom data structures and ready for the races. No need to throw away 25 years of tooling and libraries. Then we can move into languages that offer exactly the same features as C++, like D, Nim, Swift, Eiffel, Ada.
      - howinteresting 6y ago
        I've written three of those sorts of native libraries before, and it's just awfully inconvenient compared to just using Rust to be honest.