Re: [mosquitto-dev] Socket error on client

[Greg Troxel <gdt@xxxxxxxxxx>]

matthew stanger <stangerm2@xxxxxxxxx> writes:

> I did find this put out by AWS
> https://docs.aws.amazon.com/iot/latest/developerguide/mqtt.html: Summary:
> they don't follow a few MQTT 3.1.1 standards thus the following setting in
> the broker conf will cause them to kick you >_<.
> Specifically watch out for these two things:
> notifications true (.conf)
> Sending retained message
>
> Once these were removed connection worked. That second one is specifically
> frustrating because if another dev accidentally pub's something to the
> local broker with `retain true` the local broker will go into an indefinite
> loop of getting kicked by AWS. Should the `try_private false` be ignoring
> this setting for the remote broker topics?

I am not 100% clear on things, but there are two very separate issues:

  mosquitto should by default conform to the specification (and I think
  it does).  try_private seems to enable mosquitto extensions for
  syncing, and Roger already said not to enable it if the other side
  isn't mosquitto

  retained messages seem pretty normal to me, and it's surprising to
  have a connection closed for publishing one.  I could see mosquitto
  growing an option to not forward such messages to a peer (set per
  peer), or maybe to silently drop the retained flag.  And perhaps to
  make the local broker not allow retained messages, and sending naks to
  clients that publish them.


which is a long way  of saying that any accomodation for amazon not
liking retained messages should be a specific workaround option and not
default.