Question 1

How do I add a Boltun listener to my Elixir supervision tree?

Accepted Answer

You need to call `TestListener.start_link` and include it in your supervisor's child list, similar to other GenServer processes. The README mentions this but doesn't provide full examples, so refer to Elixir's Supervisor documentation for details.

Question 2

Boltun vs Phoenix PubSub for real-time updates in Elixir?

Accepted Answer

Boltun is specialized for PostgreSQL database events via LISTEN/NOTIFY, while Phoenix PubSub is a general-purpose pub-sub system for distributed Elixir apps. Use Boltun for direct database integration and Phoenix PubSub for broader application-level messaging across nodes.

Question 3

How to handle database reconnections if the PostgreSQL connection fails in Boltun?

Accepted Answer

Boltun relies on Postgrex for connections, so you must configure Postgrex's reconnection settings or use connection pools. The library itself doesn't manage reconnections, requiring additional setup to ensure reliability.

Question 4

Can I make Boltun callbacks run asynchronously?

Accepted Answer

No, callbacks are invoked synchronously by design. For asynchronous processing, you need to manually spawn tasks or use async primitives within the callback functions, which adds complexity.

Question 5

How to test Boltun listeners without a live PostgreSQL database?

Accepted Answer

Testing typically requires a running PostgreSQL instance or using mocks for Postgrex. Boltun doesn't provide testing utilities, so you'll need to set up integration tests or use libraries like Ecto Sandbox for isolated environments.

Question 6

What happens if a Boltun callback raises an error or crashes?

Accepted Answer

The README doesn't specify error handling; errors likely propagate and could crash the listener process. To prevent this, wrap callback logic in try-rescue blocks or implement supervision strategies for resilience.

Question 7

Is Boltun suitable for high-frequency notifications in PostgreSQL?

Accepted Answer

It can handle moderate loads, but synchronous execution and reliance on PostgreSQL's NOTIFY mechanism may not scale well for very high-frequency events compared to dedicated message queues, requiring careful performance testing.

boltun

What is boltun?

Overview

Use Cases

Best For

Related Projects

Found a gem we're missing?

Not Ideal For

Pros & Cons

Pros

Cons

Frequently Asked Questions