publish msg in no confirm mode

[alanxz]

publish msg in no confirm mode

[alanxz]

I understand why you want to have publish confirms turned off - the way I use them there's a substantial performance hit as client must wait for an entire round trip to the broker before proceeding.

Short Answer: I will not add this feature by simply turning off publisher confirms. (see long answer for an explanation why)

Long Answer:
The reason I decided to use publisher confirms is that it takes an asynchronous task of publishing and allows the client to treat it as a synchronous process.

Without publisher confirms handling AMQP errors in a single-threaded, non-event looped environment becomes tricky: When you publish without publisher confirms, the broker only sends something back to the client when an error occurs. Sometimes these errors result in the AMQP channel being closed, and continuing to use an AMQP channel after its been closed will result in the entire connection being shut down.

You run into the same issues with the immediate and mandatory flags on the basic.publish.

I have given thought to augmenting the API to allow for asynchronous publishing (e.g, BasicPublish returns a boost::future<> of some sort) improving the throughput of the client library by allowing programs to continue sending messages before the client library receives a publisher confirm.

[chenyujian]

i think you are right.
i think asynchronous publishing is better than simply turning off publisher confirms.
in my win xp os,when i use this library, publishing msg rate is about 800msg/s,and in no confirm mode rate raises to about 15000msg/s. i tested asynchronous publishing in other language, publish rate is about 12000msg/s

[luca3m]

I noticed a good performance boost removing confirm from BasicPublish. Do you you have some ideas about how to implement it? Right now I've simply tried to comment these lines from 537 to 552.

I imagine that you prefer something better, anyway commenting these lines are there any side effects on the library?

[alanxz]

Please read my comment above.

Repeating what I stated above: I will not disable publisher confirms in SimpleAmqpClient. I am open to being more creative about AMQP-channel usage from within the library to improve publisher performance. Or perhaps by adding an API to publish several messages at once.

If you're really bent on disabling publisher confirms in SimpleAmqpClient, you also need to disable publisher confirms by disabling confirm.select when creating new channels here).

[luca3m]

Yes, I've read your comment, I was asking some details more about how you would improve publish efficiency.

Anyway I prefer no-ack approach, thank you for your hint!

As a reference for other readers, on my branch you can find this feature (pretty simple) publish-noack