Skip to main content

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [List Home]
Re: [mosquitto-dev] Configuration of bridge on both directions

Hi Ian and all

The bridge is set with QoS 2 and the messages are also send with QoS 2, so I would expect it to work. The bridge connects before I kill the client (I send messages before killing the client and they are correctly sent).

I created a bug report in launchpad (, but if anyone thinks it should actually not work in this scenario then, I'd like to understand why.

Best regards, 
Marcelo Diniz
Em Quarta-feira, 9 de Abril de 2014 0:13, Ian Craggs <icraggs@xxxxxxxxxxxxxxxxxxxxxxx> escreveu:
Hi Marcelo,

I'm not an expert on Mosquitto itself (yet), but I think this should work.  What QoS are the messages you are sending?  If QoS 0, they don't have to be queued for disconnected clients.

Another thing to be sure of is that the bridge has connected before you kill the broker on the client, otherwise the subscription will not have been established, and no queueing will take place.

As the Mosquitto code has not yet been contributed to Eclipse, you could raise a bug at


On 04/07/2014 10:10 AM, Marcelo Diniz wrote:

I'm looking at MQTT for a way to reliably deliver messages between brokers (both directions), with message queuing when the connection goes down. From other threads I read this is is a covered use case, but I haven't found a way to configure it correctly so some guidance would be helpful.

Scenario: server and clients run each a local MQTT broker (mosquitto). Brokers in the clients are configured as bridges, connecting to the server. Client configuration is below:

connection bridge_123
clientid client_123
address localhost:1883
topic mosquittodemo/test both 2
cleansession false

The broker in the server is not configured as bridge.

Server and clients can go offline at any time, and messages should be queued locally when the connection is down. Messages are sent in both directions. The server sends messages to a given client by publishing on a topic only the client is listening (not in the config above).

I'm running a server and client on different ports to test the queuing when the connection is down. Then there are these two cases:
1. I kill the broker on the server, and continue sending messages to the client broker (which are queued). Then I restart the broker on the server, and after the bridge is reestablished the queued messages are delivered. So queuing works when sending messages client -> server.
2. I kill the broker on the client, and continue sending messages to the server broker (which should get queued). Then I restart the broker on the client. The bridge is reestablished but the old messages are not delivered. New messages are delivered as expected.

So it seems the queuing is not working on the other side of the bridge, on the broker that was not configured as a bridge.

Is my configuration wrong? Is this use case supported? Or is my way of testing (killing brokers with kill -9 to simulate a broken connection) that is not appropriate?

If it matters: I'm using mosquitto_sub and mosquitto_pub to publish and subscribe to topics.

Thank you,

mosquitto-dev mailing list

Ian Craggs                          
icraggs@xxxxxxxxxx                 IBM United Kingdom
Committer on Paho, Mosquitto

mosquitto-dev mailing list

Back to the top