when rabbitmq delete message from queue?

Question

First of all i declare exchange,queue and bind them togerther. i basicPublish a message to this queue, so there are one message you in the queue. At this time i start my consumer program(with autoAck = true) and debug it, when i run to basicConsume(xxx), the message was lost! In my opinion consumer will send basic.ack to broker when it run to the method nextDelivery(), but in fact when i will declare a consumer, the message in queue is taken. why? Can someone tell me when rabbitmq delete message from queue? after the method basicConsume() or nextDelivery()??? thx~~~

Answer 1

autoAck = true

because of this

you are telling RabbitMQ to automatically acknowledge the message when it is consumed. acknowledging a message tells RabbitMQ that it has been taken care of and RabbitMQ can delete it now.

set autoAck to false if you want to manually acknowledge the message after you are done processing it.