Papercups
oban
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Papercups | oban | |
---|---|---|
19 | 27 | |
5,615 | 3,030 | |
0.9% | - | |
0.0 | 9.3 | |
2 months ago | 3 days ago | |
Elixir | Elixir | |
MIT License | Apache License 2.0 |
Stars - the number of stars that a project has on GitHub. Growth - month over month growth in stars.
Activity is a relative number indicating how actively a project is being developed. Recent commits have higher weight than older ones.
For example, an activity of 9.0 indicates that a project is amongst the top 10% of the most actively developed projects that we are tracking.
Papercups
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Linen.dev – Building a chat app with Elixir and NextJS
The best language for the task at hand, when presented with time constraints, is the one that you already know well. OP said in the article that they authored Papercups [1]. Adopting Elixir for a websocket-push service makes a lot of sense, then. However, why don't you learn Elixir, some OTP, and then reconsider that question? You could be missing out.
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What Phoenix Elixir Tutorial do you want to see?
https://github.com/papercups-io/papercups - 5.2k stars, uses Phoenix 1.6
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Complete, Production-Ready Phoenix Reference Applications
Papercups
- Looking for recommendation of OS phoenix app to look at
- Example of an elixir CRUD app in production
- Show HN: Open-source live customer chat
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Lessons from answering 800 customer support queries in last 2 yrs as a founder
Shameless plug here if anyone is interested in an open source live chat tool check out https://github.com/papercups-io/papercups
- Create a conversation with Elixir with real code examples
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Ask HN: What novel tools are you using to write web sites/apps?
Phoneix - Elixir
We're a live message tool and it is basically what Elixir is built for https://github.com/papercups-io/papercups.
The Elixir community has been great and incredibly friendly. I originally was worried about the size of the community but that hasn't been an issue the community has been super helpful. I also think the annual stackoverflow usage surveys are very misleading because most of the community's questions get asked in ElixirForum and not on Stackoverflow.
Phoneix is the web framework of Elixir which is very similar to Rails but minus a lot of the magic has been very helpful for our productivity as well.
If I had to built another service that is websocket heavy I would definitely use Elixir. Even if it was a standard crud app I would still most likely choose Elixir.
- Papercups – open-source live customer chat in Elixir
oban
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How to Use Flume in your Elixir Application
Oban, backed by PostgreSQL or SQLite, also provides a queue-based job processing system. Exq, on the other hand, is backed by Redis. It provides features similar to Flume, but without built-in rate limiting and batch processing capabilities.
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Postgres as Queue
In Elixir land Oban[0] uses Postgres as queue and seems to work quite well.
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Zero Downtime Postgres Upgrades
I hear you on that, and can say that Postgres is incredibly capable at going beyond typical relational database workloads. One example are durable queues that are transactionally consistent with the rest of the database play a unique role in our architecture that would otherwise require more ceremony. More details here: https://getoban.pro
We are also working on shifting some workloads off of Postgres on to more appropriate systems as we scale, like logging. But we intentionally chose to minimize dependencies by pushing Postgres further to move faster, with migration plans ready as we continue to reach new levels of scale (e.g. using a dedicated log storage solution like elastic search or clickhouse).
- Deno Cron
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Switching to Elixir
You can actually have "background jobs" in very different ways in Elixir.
> I want background work to live on different compute capacity than http requests, both because they have very different resources usage
In Elixir, because of the way the BEAM works (the unit of parallelism is much cheaper and consume a low amount of memory), "incoming http requests" and related "workers" are not as expensive (a lot less actually) compared to other stacks (for instance Ruby and Python), where it is quite critical to release "http workers" and not hold the connection (which is what lead to the creation of background job tools like Resque, DelayedJob, Sidekiq, Celery...).
This means that you can actually hold incoming HTTP connections a lot longer without troubles.
A consequence of this is that implementing "reverse proxies", or anything calling third party servers _right in the middle_ of your own HTTP call, is usually perfectly acceptable (something I've done more than a couple of times, the latest one powering the reverse proxy behind https://transport.data.gouv.fr - code available at https://github.com/etalab/transport-site/tree/master/apps/un...).
As a consequence, what would be a bad pattern in Python or Ruby (holding the incoming HTTP connection) is not a problem with Elixir.
> because I want to have state or queues in front of background work so there's a well-defined process for retry, error handling, and back-pressure.
Unless you deal with immediate stuff like reverse proxying or cheap "one off async tasks" (like recording a metric), there also are solutions to have more "stateful" background works in Elixir, too.
A popular background job queue is https://github.com/sorentwo/oban (roughly similar to Sidekiq at al), which uses Postgres.
It handles retries, errors etc.
But it's not the only solution, as you have other tools dedicated to processing, such as Broadway (https://github.com/dashbitco/broadway), which handles back-pressure, fault-tolerance, batching etc natively.
You also have more simple options, such as flow (https://github.com/dashbitco/flow), gen_stage (https://github.com/elixir-lang/gen_stage), Task.async_stream (https://hexdocs.pm/elixir/1.12/Task.html#async_stream/5) etc.
It allows to use the "right tool for the job" quite easily.
It is also interesting to note there is no need to "go evented" if you need to fetch data from multiple HTTP servers: it can happen in the exact same process (even: in a background task attached to your HTTP server), as done here https://transport.data.gouv.fr/explore (if you zoom you will see vehicle moving in realtime, and ~80 data sources are being polled every 10 seconds & broadcasted to the visitors via pubsub & websockets).
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Show HN: A simple API/CLI for scheduling HTTP requests
Hi HN!
This is something I've been tinkering on for the past couple months. It's basically just an API/CLI for scheduling delayed or recurring jobs as HTTP requests.
I initially built it as a personal tool to save myself a bit of time on little side projects where I've needed scheduled/recurring alerts, but decided it could be a good opportunity to practice building out a nice landing page [0] and documentation [1]. And who knows, maybe someone else will find it useful ¯\_(ツ)_/¯
The tool relies heavily on Elixir's Oban [2] library for managing jobs, and Mintlify [3] for documentation. I also shamelessly stole most of the frontend design from Resend [4] because I'm a fan of the aesthetic and thought it would be good for my design chops to use their design as a guide. I also discovered Radix [5] UI while working on this, which ended up being immensely helpful for moving quickly on the frontend.
Anyways, I almost certainly spent a bit too much time on small UX details that are most likely utterly inconsequential, but it was a fun exercise in polish :)
All feedback is welcome!
- Choose Postgres Queue Technology
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Pg_later: Asynchronous Queries for Postgres
Idk about pgagent but any table is a resilient queue with the multiple locks available in pg along with some SELECT pg_advisory_lock or SELECT FOR UPDATE queries, and/or LISTEN/NOTIFY.
Several bg job libs are built around native locking functionality
> Relies upon Postgres integrity, session-level Advisory Locks to provide run-once safety and stay within the limits of schema.rb, and LISTEN/NOTIFY to reduce queuing latency.
https://github.com/bensheldon/good_job
> |> lock("FOR UPDATE SKIP LOCKED")
https://github.com/sorentwo/oban/blob/8acfe4dcfb3e55bbf233aa...
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Keep the Monolith, but Split the Workloads
> Bad code in a specific part of the codebase bringing down the whole app, as in our November incident.
This is a non-issue if you're using a Elixir/Erlang monolith given its fault tolerant nature.
The noisy neighbour issue (resource hogging) is still something you need to manage though. If you use something like Oban[1] (for background job queues and cron jobs), you can set both local and global limits. Local being the current node, and global the cluster.
Operating in a shared cluster (vs split workload deployments) give you the benefit of being much more efficient with your hardware. I've heard many stories of massive infra savings due to moving to an Elixir/Erlang system.
- Library for reliably running jobs
What are some alternatives?
chatwoot - Open-source live-chat, email support, omni-channel desk. An alternative to Intercom, Zendesk, Salesforce Service Cloud etc. 🔥💬
broadway - Concurrent and multi-stage data ingestion and data processing with Elixir
SvelteKit - web development, streamlined
exq - Job processing library for Elixir - compatible with Resque / Sidekiq
Gotify - A simple server for sending and receiving messages in real-time per WebSocket. (Includes a sleek web-ui)
Rihanna - Rihanna is a high performance postgres-backed job queue for Elixir
LeapChat - Ephemeral, encrypted, in-browser chat rooms
kafka_ex - Kafka client library for Elixir
LibreNews - A free and open breaking news notification platform
verk - A job processing system that just verks! 🧛
PushBits - A simple server for push notifications via Matrix (and a minimalistic alternative to Pushover and Gotify) 🚀📯
honeydew - Job Queue for Elixir. Clustered or Local. Straight BEAM. Optional Ecto. 💪🍈