Still it should be possible to implement using reactive streams right.
Could you please enlighten me on what are the some major differences you see
between a commit log and a message queue? I see them being different only in the
implementation but not functionality wise so I would be glad to hear your

On Sat, Sep 17, 2016 12:39 PM, Radoslaw Gruchalski
Kafka is not a queue. It’s a distributed commit log.


Best regards,

Radek Gruchalski

On September 17, 2016 at 9:23:09 PM, kant kodali ( wrote:

Hmm...Looks like Kafka is written in Scala. There is this thing called


streams where a slow consumer can apply back pressure if they are consuming

slow. Even with Java this is possible with a Library called RxJava and


ideas will be incorporated in Java 9 as well.

I still don't see why they would pick poll just to solve this one problem


compensating on others. Poll just don't sound realtime. I heard from some


that they would set poll to 100ms. Well 1) that is a lot of time. 2)


applications requires micro second latency. Kafka from what I understand


like has a very high latency and here is the article. I usually don't go by

articles but I ran my own experiments on different queues and my numbers


very close to this article so I would say whoever wrote this article has

done a

good Job. 3) poll does generate unnecessary traffic in case if the data



Finally still not sure why they would pick poll() ? or do they plan on

introducing reactive streams?Thanks,kant

On Sat, Sep 17, 2016 5:14 AM, Radoslaw Gruchalski


I'm only guessing here regarding if this is the reason:

Pull is much more sensible when a lot of data is pushed through. It allows

consumers consuming at their own pace, slow consumers do not slow the


system down.


Best regards,


On Sat, Sep 17, 2016 at 11:18 AM +0200, "kant kodali" <>


why did Kafka choose pull instead of push for a consumer? push sounds like


is more realtime to me than poll and also wouldn't poll just keeps polling


when they are no messages in the broker causing more traffic? please



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