nathanl
Monitor RabbitMQ queue length from Elixir?
Has anybody used Elixir to check the length of a RabbitMQ queue? It can be done with declare_queue, but it’s ugly - you have to pass the exact option you originally declared the queue with, plus :passive.
The use case is to detect when the system is backing up and respond accordingly.
Most Liked
collegeimprovements
nathanl
@collegeimprovements Oh thanks - that led me to the underlying function: AMQP.Queue — amqp v1.4.2 . Works great!
nathanl
For anyone who stumbles on this later: AMQP only supports getting the number of messages that are “Ready”, not those that are “unacked”. For the latter, you might have to use RabbitMQ’s REST API. See https://stackoverflow.com/questions/63018151/can-i-see-the-count-of-unacked-messages-in-rabbitmq-via-an-amqp-client
My system that consumes from the queue is using Broadway. In normal load, I basically never see any messages as “ready” because they’re quickly grabbed up by my Broadway pipeline. By queueing a lot of messages and putting a Process.sleep(:infinity) in my handle_message, I can see that my system will have at most N unacked messages at a time. So if I see any messages in the “ready” count, I can basically assume that there are N more being handled at the moment, which is a good enough indicator to decide whether the system is getting overloaded.
Popular in Questions
Other popular topics
Latest on Elixir Forum
Sponsor Spotlight
Catch errors, track performance, monitor hosts and more.
Categories:
Sub Categories:
Forums
Popular Tags
- #ecto
- #liveview
- #troubleshooting
- #learning-elixir
- #deployment
- #library
- #erlang
- #testing
- #genserver
- #mix
- #absinthe
- #remote-other
- #otp
- #plug
- #how-to-question
- #macros
- #postgres
- #channels
- #elixirconf
- #exunit
- #discussion
- #code-sync
- #javascript
- #podcasts
- #onsite
- #dialyzer
- #docker
- #authentication
- #umbrella
- #full-time-contract
- #podcasts-by-brainlid
- #ecto-query
- #elixir-ls
- #phoenix_html
- #iex
- #blog-post
- #graphql
- #genstage
- #ai
- #websockets
- #supervisor
- #elixirconf-us
- #advent-of-code
- #distillery
- #processes
- #api
- #forms
- #metaprogramming
- #security
- #hex
Our Sponsors
Build Elixir applications with speed and confidence.
Supporting innovation across the BEAM ecosystem.
We build reliable cloud platforms for business-critical systems.
Catch errors, track performance, monitor hosts and more.
Error tracking for Elixir devs who love to ship. Start your free account.
Producing high quality Elixir screencasts since 2017.
Enabling companies to succeed by building software people love.
The deployment platform built for Elixir: PaaS ease, VPS control.
The team behind Membrane, Popcorn, LiveDebugger. Available for hire.
Courses that'll move you from confusion to "Aha, now I get it!"