LiveDebugger is making the system run slow and memory is growing rapidly

[allenwyma]

Bug Description

live_debugger on 2 different systems is producing different effects.

On my system, it's running fine, but on their system live_debugger's memory is growing beyond 25GB and causing slow runtime.

For instance, on my computer, it's taking about 4ms to run a handle_event call, when it's taking 300-400ms for the same call on their machine.

Actual Behavior

On my system, it's running fine, but on their system live_debugger's memory is growing beyond 25GB and causing slow runtime.

For instance, on my computer, it's taking about 4ms to run a handle_event call, when it's taking 300-400ms for the same call on their machine.

Expected Behavior

Should be the same for performance.

Steps to Reproduce

This is hard to debug as we are running the same system, he's using an M3 max and I"m using an M2 max cpu.

Elixir version with Erlang/OTP

1.19.5

LiveDebugger version

0.6.1

Phoenix version

1.8.5

Phoenix LiveView version

1.1.27

Operating system

macos

Browser(s)

firefox and google chrome

[srzeszut]

Hey, thanks for the report. Could you double-check if the garbage collection option is enabled in live_debugger and if possible let us know the exact steps to reproduce the memory spike?

[allenwyma]

Hey, thanks for the report. Could you double-check if the garbage collection option is enabled in live_debugger and if possible let us know the exact steps to reproduce the memory spike?

how can i check this?

Also the codebase is the same between mine and his computer in terms of the project.

[srzeszut]

There is an option in settings to disable garbage collection.

Make sure you have garbage collection enabled.

Does this happen every time, or was it just a one time event that you can't reproduce?

Could you also share some details about the assigns size? Are you seeing a large amount of traces being generated in this case?

[kraleppa]

Also, if you can share:

1. Approximate number of LiveView processes when it’s slow
2. Does it happen only if LiveDebugger is inspecting node and/or tracing is enabled?

[AngyL75]

Hi, Garbage collection is ON on my computer.

iex(2)> LiveDebugger.API.SettingsStorage.get(:garbage_collection)
true

The memory issue is not new. In fact, on this specific project it has been like that for more than 5 months, with (1) phx.server being very slow at recompiling code, (2) eventually crashing when I was doing local test and (3) all interactions using some javascript being 100 times slower and page load also being slower and slower.

So, yes, it happens all the time, but only on my machine, NOT on @allenwyma's machine.... with same project.

[AngyL75]

Also, if you can share:
1. Approximate number of LiveView processes when it’s slow
2. Does it happen only if LiveDebugger is inspecting node and/or tracing is enabled?

We usually have 1 or 2 liveviews at the same on every page.

our configuration file is
config :live_debugger, browser_features?: true

in mix.exs, we have
{:live_debugger, "~> 0.1", only: [:dev]},

[kraleppa]

Thanks, for your responses, but we still need some more since we completely cannot reproduce it:

1. Could you please confirm you’re running the exact same LiveDebugger dependency/runtime? Can you provide the output of:

Application.spec(:live_debugger, :vsn)

2. Can you paste the LiveDebugger settings that are actually used at runtime (from its DETS settings storage)?

LiveDebugger.API.SettingsStorage.get_all()

3. Can you also paste the config values from the application env:

Application.get_all_env(:live_debugger)

Also, can you confirm that the issue reproduces on the same commit/tag of your project as @allenwyma (and that you’re using the same Elixir + OTP versions)?