I've seen this bottle neck regardless of using compression or not, bpth situations give me poor performance on sending to kafka via the scala producer api. On 1 Jan 2014 16:42, "Chris Hogue" <csho...@gmail.com> wrote:
> Hi. > > When writing that blog we were using Kafka 0.7 as well. Understanding that > it probably wasn't the primary design goal, the separate send threads per > broker that offered a separation of compression were a convenient > side-effect of that design. > > We've since built new systems on 0.8 that have concentrated high throughput > on a small number of producers and had this discovery early on as well. > > Instead we've taken responsibility for the compression before the producer > and done that on separate threads as appropriate. While helpful for > compression on the producer application the main reason for this is to > prevent the broker from uncompressing and re-compressing each message as it > assigns offsets. There's a significant throughput advantage in doing this. > > Truthfully since switching to snappy the compression throughput on the > producer is much less of a concern in the overall context of the > application. > > There was some discussion of these issues in the 'Client Improvement > Discussion' thread a while ago where Jay provided some insight and > discussion on future directions. > > -Chris > > > > > On Wed, Jan 1, 2014 at 5:42 AM, yosi botzer <yosi.bot...@gmail.com> wrote: > > > This is very interesting, this is what I see as well. I wish someone > could > > explain why it is not as explained here: > > http://engineering.gnip.com/kafka-async-producer/ > > > > > > On Wed, Jan 1, 2014 at 2:39 PM, Gerrit Jansen van Vuuren < > > gerrit...@gmail.com> wrote: > > > > > I don't know the code enough to comment on that (maybe someone else on > > the > > > user list can do that), but from what I've seen doing some heavy > > profiling > > > I only see one thread per producer instance, it doesn't matter how many > > > brokers or topics you have the number of threads is always 1 per > > producer. > > > If you create 2 producers 2 threads and so on. > > > > > > > > > > > > > > > > > > On Wed, Jan 1, 2014 at 1:27 PM, yosi botzer <yosi.bot...@gmail.com> > > wrote: > > > > > > > But shouldn't I see a separate thread per broker (I am using the > async > > > > mode)? Why do I get a better performance sending a message that has > > > fewer > > > > partitions? > > > > > > > > > > > > On Wed, Jan 1, 2014 at 2:22 PM, Gerrit Jansen van Vuuren < > > > > gerrit...@gmail.com> wrote: > > > > > > > > > The producer is heavily synchronized (i.e. all the code in the send > > > > method > > > > > is encapsulated in one huge synchronized block). > > > > > Try creating multiple producers and round robin send over them. > > > > > > > > > > e.g. > > > > > > > > > > p = producers[ n++ % producers.length ] > > > > > > > > > > p.send msg > > > > > This will give you one thread per producer instance. > > > > > > > > > > I'm working on an async multi threaded producer for kafka, but its > > > > nothing > > > > > near complete yet. > > > > > https://github.com/gerritjvv/kafka-fast > > > > > > > > > > > > > > > Regards, > > > > > Gerrit > > > > > > > > > > > > > > > On Wed, Jan 1, 2014 at 1:17 PM, yosi botzer <yosi.bot...@gmail.com > > > > > > wrote: > > > > > > > > > > > Hi, > > > > > > > > > > > > I am using kafka 0.8. I have 3 machines each running kafka > broker. > > > > > > > > > > > > I am using async mode of my Producer. I expected to see 3 > different > > > > > threads > > > > > > with names starting with ProducerSendThread- (according to this > > > > article: > > > > > > http://engineering.gnip.com/kafka-async-producer/) > > > > > > > > > > > > However I can see only one thread with the name > > *ProducerSendThread-* > > > > > > > > > > > > This is my producer configuration: > > > > > > > > > > > > server=1 > > > > > > topic=dat7 > > > > > > metadata.broker.list= > > > > > > ec2-54-245-111-112.us-west-2.compute.amazonaws.com:9092 > > > > > > ,ec2-54-245-111-69.us-west-2.compute.amazonaws.com:9092, > > > > > > ec2-54-218-183-14.us-west-2.compute.amazonaws.com:9092 > > > > > > serializer.class=kafka.serializer.DefaultEncoder > > > > > > request.required.acks=1 > > > > > > compression.codec=snappy > > > > > > producer.type=async > > > > > > queue.buffering.max.ms=2000 > > > > > > queue.buffering.max.messages=1000 > > > > > > batch.num.messages=500 > > > > > > > > > > > > > > > > > > *What am I missing here?* > > > > > > > > > > > > > > > > > > BTW, I have also experienced very strange behavior regrading my > > > > producer > > > > > > performance (which may or may not be related to the issue above). > > > > > > > > > > > > When I have defined a topic with 1 partition I got much better > > > > throughput > > > > > > comparing to a topic with 3 partitions. A producer sending > messages > > > to > > > > a > > > > > > topic with 3 partitions had much better throughput comparing to a > > > topic > > > > > > with 12 partitions. > > > > > > > > > > > > I would expect to have best performance for the topic with 12 > > > > partitions > > > > > > since I have 3 machines running a broker each of with 4 disks > (the > > > > broker > > > > > > is configured to use all 4 disks) > > > > > > > > > > > > *Is there any logical explanation for this behavior?* > > > > > > > > > > > > > > > > > > > > >
