heroku-buildpack-jemalloc VS Que

Using jemalloc instead of regular malloc helps too. The exact way to do this depends on the platform you use, but it is pretty simple on Heroku. Just set heroku-buildpack-jemalloc as the first buildpack (ahead of the heroku/ruby buildpack).

I've recently discovered jemalloc, specifically when used with Heroku.

"Using jemalloc instead of regular malloc helps too. The exact way to do this depends on the platform you use, but it is pretty simple on Heroku. Just set heroku-buildpack-jemalloc as the first buildpack (ahead of the heroku/ruby buildpack)."

FYI, remember to set JEMALLOC_ENABLED=true in your env to actually turn it on.

https://github.com/gaffneyc/heroku-buildpack-jemalloc

Like I mentioned earlier, Digital Ocean App Platform uses the same buildpacks as Heroku to deploy your apps. This means that most apps that can be deployed on Heroku should also be deployed on Digital Ocean. There is one big caveat, though; you can't select which buildpack(s) to use. This means you have to rely on Digital Ocean to pick the right ones for your project. It also gives you a bit less flexibility in how your app runs. For instance, I recently configured our app at work to run using jemalloc, a malloc alternative that often has better performance for Ruby apps. We did that via a buildpack heroku-buildpack-jemalloc, which allowed us to switch to jemalloc without any app changes. Customizations to the build environment like this don't seem possible given the Digital Ocean App Platform's current offerings.

> Can you define "low throughput"?

<1000 messages per minute

Not saying SKIP LOCKED can't work with that many. But you'll probably want to do something better.

FWIW, Que uses advisory locks [1]

[1] https://github.com/que-rb/que

Probably worth mentioning that aside from delayed_job there are at least two more modern alternatives backed by the DB: Que and good_job.

Good article. Sidekiq is a good, well respected too. However if you are starting out I would recommend not using it, and instead choosing a DB based queue system. We have great success with que, but there are others like good_job.

(not sure why this comment was dead, I vouched for it)

There are a lot of ways to implement a queue in an RDBMS and a lot of those ways are naive to locking behavior. That said, with PostgreSQL specifically, there are some techniques that result in an efficient queue without locking problems. The article doesn't really talk about their implementation so we can't know what they did, but one open source example is Que[1]. Que uses a combination of advisory locking rather than row-level locks and notification channels to great effect, as you can read in the README.

[1]: https://github.com/que-rb/que

https://github.com/que-rb/que

This one seems to be the most performant. By a lot too, from my understanding (haven't ran any benchmark myself, but the readme shows some good postgres knowledge)

Que seems like a good alternative if one doesn't want to use Reids. However, given that most apps need Redis (and have it within their infrastructure) nowadays, I still think that Sidekiq is the better option in the generic case.

Implementations that use advisory locks like https://github.com/que-rb/que are much more efficient (atleast when I last tested) and will easily reach 10k job/s on even very modest hardware.

There is a Go port of Que but you can also easily port it to any language you like. I have a currently non-OSS implementation in Rust that I might OSS someday when I have time to clean it up.

It’s also possible to use advisory locks to implement a job queue in Postgres. See e.g. Que[1]. Note there are a fair number of corner cases, so studying Que is wise if trying to implement something like this, as well as some (a bit older) elaboration[2].

We implemented a similar design to Que for a specific use case in our application that has a known low volume of jobs and for a variety of reasons benefits from this design over other solutions.

[1]: https://github.com/que-rb/que

Do also take into consideration que-scheduler (disclaimer, am author). It is built on top of the robust que async job system.