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labels:

summary: 'XEP-0198: Reliability and fast reconnects for XMPP'

...

Introduction

============

By default XMPP is as reliable as your network is. Unfortunately in some

cases that is not very reliable - in some network conditions disconnects

can be frequent and message loss can occur.

To overcome this, XMPP has an optional extension (XEP-0198: Stream

Management) which, when supported by both the client and server, can

allow a client to resume a disconnected session, and prevent message

loss.

Details

=======

When using XEP-0198 both the client and the server keep a queue of the

most recently sent stanzas - this is cleared when the other end

acknowledges they have received the stanzas. If the client disconnects,

instead of marking the user offline the server pretends the client is

still online for a short (configurable) period of time. If the client

reconnects within this period, any stanzas in the queue that the client

did not receive are re-sent.

If the client fails to reconnect before the timeout then it is marked

offline as normal, and any stanzas in the queue are returned to the

sender as a "recipient-unavailable" error.

Configuration

=============

  Option                         Default           Description

  ------------------------------ ----------------- -----------------------------------------------------------------------------------------

  `smacks_hibernation_time`      300 (5 minutes)   The number of seconds a disconnected session should stay alive for (to allow reconnect)

  `smacks_enabled_s2s`           false             Enable Stream Management on server connections? *Experimental*

  `smacks_max_unacked_stanzas`   0                 How many stanzas to send before requesting acknowledgement

Compatibility

=============

  ----- -----------------------------------

  0.9   Works

  0.8   Works, use version [7693724881b3]

  ----- -----------------------------------

Clients

=======

Clients that support XEP-0198:

-   Gajim

-   Swift (but not resumption, as of version 2.0 and alphas of 3.0)

-   Psi (in an unreleased branch)

-   Conversations

-   Yaxim

[7693724881b3]: //hg.prosody.im/prosody-modules/raw-file/7693724881b3/mod_smacks/mod_smacks.lua