The option is supposed to be used when `allow_local_users`
and `allow_transports` are not enough. It's an ACL where `deny`
means the message will be rejected (or a CAPTCHA would be
generated for a presence), and `allow` means the sender is
whitelisted and the stanza will pass through.
The default value is `none`, which means nothing is whitelisted.
The option emulates legacy behaviour which registers all routes
defined in `hosts` on a component connected. This behaviour
is considered harmful in the case when it's desired to multiplex
different components on the same port, so, to disable it,
set `global_routes` to `false`. The default value is `true`,
e.g. legacy behaviour is emulated: the only reason for this is
to maintain backward compatibility with existing deployments.
Since we got rid of all bottle-neck processes and we have
a connection pool for every database, the option is no longer
needed and in fact is detrimental: in practice what you get
is just a bunch of overloaded processes in the IQ handlers pool
no matter how much you increase the `iqdisc` value.
Given that there are close to zero operators understanding
the meaning of the option and, hence, not using it all,
it's not simply deprecated but completely removed.
The commit also deprecates the following functions:
- gen_iq_handler:add_iq_handler/6
- gen_iq_handler:handle/5
- gen_iq_handler:iqdisc/1
If the client acknowledged more stanzas than the server sent, close the
connection with a stream error rather than hiding client bugs by silently
adjusting the server's count.
If set to `true`, all incoming XML packets are fully validated
against known schemas. If an error occurs, the packet will be bounced
with the corresponding error reason. The default value is `false`.
The option might be useful to protect client software from sofisticated
bugs related to XML validation as well as for client developers
who want to catch validation errors at early stage of development.
Note that the option might have slight performance impact, so use it
with care on loaded machines.
The option controls how many avatars a user can upload per minute.
The option takes positive integer values. The default is 10.
Note that the option only takes effect when an avatar is about
to convert to a different format, i.e. it implies that `convert`
option is configured.