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Show HN: Goralim - a rate limiting pkg for Go to handle distributed workloads

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Re: Show HN: Goralim - a rate limiting pkg for Go to handle distributed workloads

#11

a minimal rate limiting package for Golang microservice. small weekend project. feedback and stars will be appreciated.

Good for you doing a thing! Please understand the community is likely very wary of single maintainer, weekend project, high risk dependencies right now.

Re: Show HN: Goralim - a rate limiting pkg for Go to handle distributed workloads

#12
post #7

> It is capabale to handle distributed workload with its redis database support sounds like this is limited by redis. For many organizations, this is fine. At my last gig, we used redis for deduplication and it required over 150 redis nodes with deterministic routing and consensus. Redis reportedly could support 200k rps per node, but in our case, we wouldn't see it get passed around 50k rps no matter how we tuned it…

RPS meaning reads or writes? What's the distribution of message sizes, and how large is your total dataset? What specs (core count, NIC) did each node have? I'm asking because without this info, RPS is not a particularly useful metric. As an extreme example, if your dataset is <1MB, you could likely serve read-heavy requests from your SmartNIC's dcache at close to line rate.

It's been a number of years since I worked on it. I can try to answer your questions. The calls were nearly entirely INCR calls against keys that were typically around 150 bytes long and app logic was based on the return values. I believe each node took up around 20GB of memory when saturated. Redis uses a single CPU, so core count shouldn't matter, no? I'm not entirely sure what our NIC situation was, but it was tuned to handle gigabit traffic.

Re: Show HN: Goralim - a rate limiting pkg for Go to handle distributed workloads

#13

a minimal rate limiting package for Golang microservice. small weekend project. feedback and stars will be appreciated.

There aren't any tests...? If folks are looking for a serious rate limiting package for Go, limiter is a good start: https://github.com/ulule/limiter

I'm sure that the people needing a "serious" solution would realize that a weekend project is probably not that.

Re: Show HN: Goralim - a rate limiting pkg for Go to handle distributed workloads

#14

Earlier quoted context omitted.

There aren't any tests...? If folks are looking for a serious rate limiting package for Go, limiter is a good start: https://github.com/ulule/limiter

I'm sure that the people needing a "serious" solution would realize that a weekend project is probably not that.

Still, the README says:

> For production use, fork it and made changes based on your need.

...instead of the standard "this is work in progress/just a prototype/weekend project, don't use it in production!" disclaimer (which of course won't reliably stop people from using it in production either, but at least they can't say they haven't been adequately warned).

Re: Show HN: Goralim - a rate limiting pkg for Go to handle distributed workloads

#15

> It is capabale to handle distributed workload with its redis database support sounds like this is limited by redis. For many organizations, this is fine. At my last gig, we used redis for deduplication and it required over 150 redis nodes with deterministic routing and consensus. Redis reportedly could support 200k rps per node, but in our case, we wouldn't see it get passed around 50k rps no matter how we tuned it…

> An interesting addition to this library would be to use an interface and allow your backing datastore of choice allowing teams to use redis, zookeeper, an in-mem Go instance of the same library, sql, etc.

Thanks for the feedback. I'm gonna implement an in-mem Go instance for local dev, but not sure if that will be enough to use in prod. also, in the next release, I will make redis optional.

Re: Show HN: Goralim - a rate limiting pkg for Go to handle distributed workloads

#16
post #6

Given most of the backends use round robin for loadbalancing, having in-memory counter should be enough. Removing redis as downstream dependency is a big win. For the redis implementation, there should be fallback to in-memory counting instead blocking altogether. Currently the redis is a SPOF for the entire service.

> Given most of the backends use round robin for loadbalancing, having in-memory counter should be enough. Removing redis as downstream dependency is a big win.

thanks for the feedback. planning to make redis optional in next release.

Re: Show HN: Goralim - a rate limiting pkg for Go to handle distributed workloads

#17
1. some tests, over the wire preferably, would be nice

2. redis.go does not seem to be nessary it just changes signature of redis client constructor without much difference, might as well inline its contents

3. using fmt too much, if you don't need run time variables encoding, can do something more simpler. like writing to w.Write([]byte) directly. fmt uses reflect and runtime type detection, better avoid if not needed.

4. code comments do not follow godoc conventions. they should start from symbol name. did you run go fmt and some basic linters?

5. mutex is not used. and it should be pointer.

Re: Show HN: Goralim - a rate limiting pkg for Go to handle distributed workloads

#18
post #7

Earlier quoted context omitted.

RPS meaning reads or writes? What's the distribution of message sizes, and how large is your total dataset? What specs (core count, NIC) did each node have? I'm asking because without this info, RPS is not a particularly useful metric. As an extreme example, if your dataset is <1MB, you could likely serve read-heavy requests from your SmartNIC's dcache at close to line rate.

It's been a number of years since I worked on it. I can try to answer your questions. The calls were nearly entirely INCR calls against keys that were typically around 150 bytes long and app logic was based on the return values. I believe each node took up around 20GB of memory when saturated. Redis uses a single CPU, so core count shouldn't matter, no? I'm not entirely sure what our NIC situation was, but it was tun…

Did you tune the file descriptor limits?

Re: Show HN: Goralim - a rate limiting pkg for Go to handle distributed workloads

#19

1. some tests, over the wire preferably, would be nice 2. redis.go does not seem to be nessary it just changes signature of redis client constructor without much difference, might as well inline its contents 3. using fmt too much, if you don't need run time variables encoding, can do something more simpler. like writing to w.Write([]byte) directly. fmt uses reflect and runtime type detection, better avoid if not need…

I really like the idea of getting code reviews from Hacker News for personal projects. There's so much knowledge and passion on here, it could be really useful. It would also help for me, as a bystander, to understand the context of these recommendations. I've done a bit of Go, and some of these sound useful to know.

Re: Show HN: Goralim - a rate limiting pkg for Go to handle distributed workloads

#20

Earlier quoted context omitted.

It's been a number of years since I worked on it. I can try to answer your questions. The calls were nearly entirely INCR calls against keys that were typically around 150 bytes long and app logic was based on the return values. I believe each node took up around 20GB of memory when saturated. Redis uses a single CPU, so core count shouldn't matter, no? I'm not entirely sure what our NIC situation was, but it was tun…

Did you tune the file descriptor limits?

yeah, good call out. We did. One of the things a lot of folks stub their toe on when starting to scale up
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