[rabbitmq-discuss] problematic ACKs of messages

[Cermak, Marek]

Hi everybody,
we use erlang client and we have sometime problem ACKing messages. Connection is opened as a direct (from rabbit plugin), delivery is handled in gen_server

handle_info({#'basic.deliver'{} = Deliver, Content}, State) ->
	#'basic.deliver'{delivery_tag = DTag, routing_key = BindingKey} = Deliver,
...
working with the message
...
amqp_channel:cast(SrcChannel, #'basic.ack'{delivery_tag = DTag}).
lager:info("received, ack sent - ~p", [DTag]),
...

Lager outputs i.e.
2013-02-06 10:47:15.661 [info] <0.813.0> received, ack sent - 1

and then there's an error like this
2013-02-06 10:47:15.664 [error] <0.173.0> connection <0.718.0>, channel 1 - error: {amqp_error,precondition_failed,"unknown delivery tag 2",'basic.ack'}

although the process sent delivery tag 1. Version of Rabbit is 2.8.4. Where is the problem? Thanks.

Regards,
Marek