Thanks Dongjin. One minor suggestion: we should mention that the broker side configs are also topic configs (i.e. can be set for a given topic).
Ismael On Sun, Jan 6, 2019, 10:37 AM Dongjin Lee <dong...@apache.org wrote: > Happy new year. > > I just updated the title and contents of KIP and Jira issue, with updated > draft implementation. Now both of compression level and buffer size options > are available to producer and broker configuration. You can check the > updated KIP from modified URL: > > > https://cwiki.apache.org/confluence/display/KAFKA/KIP-390%3A+Allow+fine-grained+configuration+for+compression > > Please have a look when you are free. > > Thanks, > Dongjin > > On Mon, Dec 3, 2018 at 12:50 AM Ismael Juma <isma...@gmail.com> wrote: > > > The updated title sounds fine to me. > > > > Ismael > > > > On Sun, Dec 2, 2018, 5:25 AM Dongjin Lee <dong...@apache.org wrote: > > > > > Hi Ismael, > > > > > > Got it. Your direction is perfectly reasonable. I am now updating the > KIP > > > document and the implementation. > > > > > > By allowing the buffer/block size to be configurable, it would be > better > > to > > > update the title of the KIP like 'Allow fine-grained configuration for > > > compression'. Is that right? > > > > > > @Other committers: > > > > > > Is there any other opinion on allowing the buffer/block size to be > > > configurable? > > > > > > Thanks, > > > Dongjin > > > > > > On Thu, Nov 29, 2018 at 1:45 AM Ismael Juma <ism...@juma.me.uk> wrote: > > > > > > > Hi Dongjin, > > > > > > > > To clarify, I mean a broker topic config with regards to point 1. As > > you > > > > know, compression can be done by the producer and/or by the broker. > The > > > > default is for the broker to just use whatever compression was used > by > > > the > > > > producer, but this can be changed by the user on a per topic basis. > It > > > > seems like it would make sense for the configs to be . consistent > > between > > > > producer and broker. > > > > > > > > For point 2, I haven't looked at the implementation, but we could do > it > > > in > > > > the `CompressionType` enum by invoking the right constructor or > > > retrieving > > > > the default value via a constant (if defined). That's an > implementation > > > > detail and can be discussed in the PR. The more general point is to > > rely > > > on > > > > the library defaults instead of choosing one ourselves. > > > > > > > > For point 3, I'm in favour of doing that in this KIP. > > > > > > > > Ismael > > > > > > > > On Wed, Nov 28, 2018 at 7:01 AM Dongjin Lee <dong...@apache.org> > > wrote: > > > > > > > > > Thank you Ismael, here are the answers: > > > > > > > > > > *1. About topic config* > > > > > > > > > > After some consideration, I concluded that topic config doesn't > need > > to > > > > > support compression.level. Here is why: since the compression is > > > > conducted > > > > > by the client, the one who can select the best compression level is > > the > > > > > client itself. Let us assume that the compression level is set at > the > > > > topic > > > > > config level. In that case, there is a possibility that the > > compression > > > > > level is not optimal for some producers. Actually, Kafka's go > client > > > also > > > > > supports compression level functionality for the producer config > > only. > > > > > <https://github.com/Shopify/sarama/blob/master/config.go> (wait, > do > > we > > > > > need > > > > > to add this reasoning in the KIP, rejected alternatives section?) > > > > > > > > > > *2. About default level* > > > > > > > > > > As of current draft implementation, the default compression is set > on > > > the > > > > > CompressionType enum. Of course, changing this strategy into > relying > > > on a > > > > > method from the library to pick the default compression level seems > > > > > possible, like `GZIPBlockOutputStream` does. In this case, we need > to > > > add > > > > > similar wrapper class for zstd and modify lz4 the wrapper also. Add > > to > > > > > this, it seems like we need to explicitly state that we follow the > > > > default > > > > > compression level of the codec in the documentation. Is this what > you > > > > > intended? > > > > > > > > > > *3. Whether to allow the buffer/block size to be configurable* > > > > > > > > > > Well, As of current draft implementation, the lz4 level is > > implemented > > > as > > > > > block size; this is caused by my misunderstanding on lz4. After > > > reviewing > > > > > lz4 today, I found that it also supports compression level of 1~16 > > > > > (default: 1), not block size. I will fix it in this weekend by > > updating > > > > the > > > > > wrapper class. > > > > > > > > > > For the problem of the buffer/block size, I have no strong opinion. > > If > > > > the > > > > > community needs it, I will do it all together. How do you think? > > > > > > > > > > In short, it seems like I need to update the KIP document for issue > > #1 > > > > and > > > > > update the compression wrapper for issue #2, #3. Is this okay? > > > > > > > > > > Thanks, > > > > > Dongjin > > > > > > > > > > On Wed, Nov 28, 2018 at 12:34 AM Ismael Juma <isma...@gmail.com> > > > wrote: > > > > > > > > > > > Thanks for the KIP, this is helpful. A few questions: > > > > > > > > > > > > 1. Have we considered whether we want to allow a similar topic > > > config? > > > > > > 2. Can we rely on a method from the library to pick the default > > > > > compression > > > > > > level if compression.level is not set? We do it for gzip and it > > would > > > > > seem > > > > > > reasonable to do something similar for the other compression > > > libraries. > > > > > > 3. Do we want to allow the buffer/block size to be configurable? > > This > > > > has > > > > > > an impact on memory usage and people may want to trade > compression > > > for > > > > > > less/more memory in some cases. For example, the default for LZ4 > is > > > > 64KB > > > > > > which is a bit high. > > > > > > > > > > > > Ismael > > > > > > > > > > > > On Sun, Nov 18, 2018, 2:07 PM Dongjin Lee <dong...@apache.org > > wrote: > > > > > > > > > > > > > Hello dev, > > > > > > > > > > > > > > I hope to initiate the discussion of KIP-390: Add producer > option > > > to > > > > > > adjust > > > > > > > compression level > > > > > > > < > > > > > > > > > > > > > > > > > > > > > > > > > > > > https://cwiki.apache.org/confluence/display/KAFKA/KIP-390%3A+Add+producer+option+to+adjust+compression+level > > > > > > > >. > > > > > > > All feedbacks will be highly appreciated. > > > > > > > > > > > > > > Best, > > > > > > > Dongjin > > > > > > > > > > > > > > -- > > > > > > > *Dongjin Lee* > > > > > > > > > > > > > > *A hitchhiker in the mathematical world.* > > > > > > > > > > > > > > *github: <http://goog_969573159/>github.com/dongjinleekr > > > > > > > <http://github.com/dongjinleekr>linkedin: > > > > > > kr.linkedin.com/in/dongjinleekr > > > > > > > <http://kr.linkedin.com/in/dongjinleekr>slideshare: > > > > > > > www.slideshare.net/dongjinleekr > > > > > > > <http://www.slideshare.net/dongjinleekr>* > > > > > > > > > > > > > > > > > > > > > > > > > > > > -- > > > > > *Dongjin Lee* > > > > > > > > > > *A hitchhiker in the mathematical world.* > > > > > *github: <http://goog_969573159/>github.com/dongjinleekr > > > > > <https://github.com/dongjinleekr>linkedin: > > > > kr.linkedin.com/in/dongjinleekr > > > > > <https://kr.linkedin.com/in/dongjinleekr>speakerdeck: > > > > > speakerdeck.com/dongjin > > > > > <https://speakerdeck.com/dongjin>* > > > > > > > > > > > > > > > > > > -- > > > *Dongjin Lee* > > > > > > *A hitchhiker in the mathematical world.* > > > *github: <http://goog_969573159/>github.com/dongjinleekr > > > <https://github.com/dongjinleekr>linkedin: > > kr.linkedin.com/in/dongjinleekr > > > <https://kr.linkedin.com/in/dongjinleekr>speakerdeck: > > > speakerdeck.com/dongjin > > > <https://speakerdeck.com/dongjin>* > > > > > > > > -- > *Dongjin Lee* > > *A hitchhiker in the mathematical world.* > *github: <http://goog_969573159/>github.com/dongjinleekr > <https://github.com/dongjinleekr>linkedin: kr.linkedin.com/in/dongjinleekr > <https://kr.linkedin.com/in/dongjinleekr>speakerdeck: > speakerdeck.com/dongjin > <https://speakerdeck.com/dongjin>* >
