pause consuming with auto ack true / rate limit with with auto ack true

[parsibox]

Is your feature request related to a problem? Please describe.

i need to pause consuming in auto ack true mode
i do not want to lose consumed message that were in ram
i just want not get new message from my queue

Describe the solution you'd like

i need to set a message rate for consume data from my queue in auto ack mode
for example i add 10000 record to my queue and i want only get max 500 message per second
i use prefetch 500 but it only work with auto ack false
please advice me

Describe alternatives you've considered

No response

Additional context

No response

[lukebakken]

Thanks for using RabbitMQ and this AMQP client library.

i need to set a message rate for consume data from my queue in auto ack mode

This is not supported. By design, auto ack mode does not limit the message rate to your consumer.

If you wish to limit the rate of messages to your consumer, and not lose messages that are in RAM, you MUST use manual ack mode.

If you think about it, this applies to ANY network protocol, not just AMQP.

[parsibox]

so at least is there anyway to stop consuming for auto ack mode without lose data?
if we use chanel.close is it safe?

[lukebakken]

so at least is there anyway to stop consuming for auto ack mode without lose data?
if we use chanel.close is it safe?

If your program crashes before processing all of the in-flight messages, you will lose them. RabbitMQ considers them processed immediately due to auto ack.

Again, this is due to how computers and networks work, and is not specific to RabbitMQ.

[parsibox]

no i manually want to stop consuming and after a while again start consuming
but i do not want to lose any data
i want to count received data and for example if reached 1000 i stop consuming and actually i should receive more than 1000 data because some of them is in ram , i want processed that i items after stop consuming and when all received data processed again start consuming

also if we have another method like Get that could received more than 1 data from queue it is very good for us
for example we only want to get maximum 1000 item in one call and again repeat this work ==> is there any method for it?

[lukebakken]

• Do NOT use auto ack
• Set a prefetch of 1000
• Consume from your queue, and save the messages in RAM (a list, hash table, whatever)
• Process the 1000 messages.
• When done, acknowledge the entire batch by setting multiple to true and using the last delivery tag.
• Repeat

[parsibox]

thanks a lot