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Until the GC kicks in and steals a full 200usec + a bunch of your throughput...

(Holy shit, who is downvoting this? It's literally the whole article!)



If your path is sensitive to 200us of latency you should probably optimize your application and tune your GC. Typically 200us for freeing all unreachable memory is not a big deal.


> If your path is sensitive to 200us of latency you should probably optimize your application and tune your GC.

okay, you've done this, three years later and it's the same thing again since you need to accomodate the new features. your users haven't upgraded their computers. what do you do ?


Run a profiler and optimize again.


Your original code is already optimized as much as is possible outside of the things mentioned by OP


Don't guess, measure.

Then just like C, writing a tiny set of functions in Assembly is always an option.


Keep in mind that I am referring to this:

> If your path is sensitive to 200us of latency you should probably optimize your application and tune your GC.

> Don't guess, measure.

yes, I am saying that the original code has already gone through a complete optimization process, everything is written in written in assembly, and you are at 970us on your 1ms time budget. (I'm not pulling those out of thin air, I was literally at a client yesterday with some real-time code with a 1ms deadline on a desktop OS and we have to cram as much things as possible in that millisecond)


Well in that case there is no way around upgrading the hardware, a 486 won't play a MP4 no matter how hand tuned the Assembly code is.


Properly written Go code (or even Java for that matter) will try to minimize allocations. For Java, unless I am mistaken pause-less GC is only offered by Azul - $$


>or even Java

Just in case you may be unaware, the latest GCs for Java (Shenandoah, ZGC) are miles ahead of anything available for Go due to sheer age and manpower. Parallel and Pauseless are easily achievable in most cases.


> Latest GCs for Java (Shenandoah, ZGC) are miles ahead of anything available.

Beyond hyperbole, do you have any actual comparison of Go vs Java GC performance?


Java's GC is better but Go's GC is also parallel and "pauseless" - iirc ZGC is 50-500usec which is comparable to Go's target 200usec.

The point is, neither is "five orders of magnitude" below 20ms. And neither needs zero CPU even if it doesn't block other threads.


Yeah, the whole point of the article is that gRPC v2 (and frankly v1 for that matter) are not “properly written” to do this.




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