Re: [mqtt] CONNECT Will Msg in context of KeepAlive timeout

[Dave Locke <locke@uk.ibm.com>]

For the server to detect a Keepalive timeout
 it must not have seen a PINGREQ (or other MQTT activity from the
client) for a minimum of the keepalive interval.  Once the server
has detected a keepalive timeout  the MQTT connection is deemed to
be broken and the server will initiate a shutdown of the connection including
sending the LWAT if one was requested.

The PINGREQ is always initiated from
the client.  If the client does not receive a PINGRESP within the
keepalive interval it deems the connection to be broken and should shutdown
the connection.   


All the best 
Dave 
  



From:      
 "Mr. Allan Cornish"
<acornish@inetco.com>
To:      
 mqtt@lists.oasis-open.org,

Date:      
 27/03/2013 00:26
Subject:    
   [mqtt] CONNECT
Will Msg in context of KeepAlive timeout
Sent by:    
   <mqtt@lists.oasis-open.org>

---

This is probably a dumb question, but i would like
to clarify the following sequence:

Client sends MQTT CONNECT + 'Will' msg, +ve KeepAlive
Server sends MQTT CONNACK
Keep Alive timeout occurs
Server sends MQTT PINGREQ, no response from client.
Server drops TCP connection.

Section 2.2 Will flag specifies 'Sending a Will message is not triggered
by the server receiving a DISCONNECT message from the client.'

Section 2.2 Keep Alive timer specifies 'If the server does not receive
... it disconnects the client as if the client had sent a DISCONNECT message.'

Does this mean that if a client fails to respond and the server drops the
TCP connection, the Will message is not published?

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