Catching maximum message size exceeded

[daleif]

Just had issue with an "The connection was reset" problem due to trying to upload a file that was a bit too big.

Under morbo I can see I get [trace] Maximum message size exceeded is there a hook one can use to catch these so we can inform the user properly instead of getting these connection was reset errors?

So far I haven't figured out what is the best approach here. I'd also like to inform webmaster when these happen. But it seems I need to catch them quite early.

[kraih]

I believe that is still not possible.

[daleif]

@s1037989 stupid question, as I hardly ever use the various events.

Where exactly would one subscribe to that error event? It is probably some $self->on('error'....) somewhere. But it keeps giving me errors or does not do anything. (one of the reasons why I tend to no use them, they are a bit confusing.)

[s1037989]

@daleif Not stupid at all as I'm just grasping for straws... I've never used it in your situation, but since Mojo::Message is a sub class of Mojo::EventEmitter which has an error event, I thought maybe if you attached something like a $c->req->on(error => sub {...}) event handler maybe it'll pop and get something to allow you to throw a log? But I did see in the code that sub _limit {} doesn't explicitly $self->emit('error') or die or Mojo::Exception->throw... Anyway, what you want, I reckon, is just some event or hook that will give you the opportunity to add an additional $log->error to the $log->trace that's already called by sub _limit {}. I think you were generally looking for a hook solution which I think would generally require detecting the problem by analyzing state at the time of the hook, whereas events are thrown in response to certain conditions and no deep state inspection is usually needed. EventEmitter is probably one of the most power mechanisms in Mojo so don't give up on them!

[s1037989]

@daleif Sorry for the misleading suggestion... doesn't look good. I modified request.t L25 to add $req->on(error => sub { warn 'ERROR!' }); but it never popped (unlike $req->on(finish => sub {})).
So what about a before_dispatch hook that looks at $c->req->error->{message}?

[s1037989]

Looks like hook might be the right answer!

$ env MOJO_LOG_LEVEL=info perl -Mojo -E 'app->max_request_size(100); hook before_dispatch => sub ($c) { $c->log->error($c->req->error->{message}) if $c->req->error }; a("/" => {text => "ok"}); app->start' get /
ok

$ env MOJO_LOG_LEVEL=info perl -Mojo -E 'app->max_request_size(1); hook before_dispatch => sub ($c) { $c->log->error($c->req->error->{message}) if $c->req->error }; a("/" => {text => "ok"}); app->start' get /
[2024-11-21 20:45:53.42485] [2433908] [error] [OnoozdbjB4_m] Maximum message size exceeded

[daleif]

I'll give that a go. Is already using before_render to send crashes directly to my inbox. Not sure if before_render is the right place for that, but it works. I'll do some testing with before_dispatch to see if it works as intended.