Phoenix server randomly stops serving requests with no error reported

[dimitarvp]

Have you tried manually calling the function in iex? And then do several Cachex.ttl calls and see if the TTL value is decreasing?

[wanton7]

I think your problem is that you are calling Cachex.expire inside fetch function and key not be created until you exit that function, It should be done this way.

From ttl option of `Cachex.fetch` · Issue #195 · whitfin/cachex · GitHub

with { :commit, _val } ← Cachex.fetch(:my_cache, cache_key, &my_func/1) do
Cachex.expire(:my_cache, cache_key, :timer.seconds(1)
{ :commit, val }
end

[lucaong]

That sounds correct to me. You can also add it to the existing case statement:

Cachex.fetch(:github, "avatar_url", fn() ->
  # ...
|> case do
  {:error, _} -> nil
  {_, nil} -> {:error, :not_found}
  {success, result} when success in [:ok, :loaded, :commit] ->
    if success == :commit, do: Cachex.expire(:github, "avatar_url", :timer.minutes(5))
    result
end

Just an off-topic comment about that case statement: it seems to me that it does not make much sense that you turn {:error, _} to nil but you return {:error, :not_found} if the result is nil. I would try to be consistent there and either return nil or {:error, cause} in both cases, whatever is appropriate.

[BenSchZA]

@wanton7 I think you found the issue I’ll give that a try.

@lucaong Thanks for the alternative format. Re. the case statement, I found that solution in an issue thread somewhere, and there was some answer as to why it should be that way, but couldn’t really make sense of it.