As Kafka 2.0.0 was released, let's reboot this issue, KIP-110 <https://cwiki.apache.org/confluence/display/KAFKA/KIP-110%3A+Add+Codec+for+ZStandard+Compression> .
For newcomers, Here is some summary of the history: KIP-110 was originally worked for the issue KAFKA-4514 but, it lacked benchmark results to get the agreement of the community. Later, Ivan Babrou and some other users who adopted the patch provided their excellent performance report which is now included in the KIP, but it postponed again because of the community was busy for 2.0.0 release. It is why I now reboot this issue. The following is the current status of the feature: You can check the current draft implementation here <https://github.com/apache/kafka/pull/2267>. It is based on zstd 1.3.5 and periodically rebased onto the latest trunk[^1]. The issues that should be addressed is like following: *1. Backward Compatibility* To support old consumers, we need to take a strategy to handle the old consumers. Current candidates are: - Bump API version - Leave unchanged: let the old clients fail. - Improve the error messages: *2. Dictionary Support* To support zstd's dictionary feature in the future (if needed), we need to sketch how it should be and leave some room for it. As of now, there has been no discussion on this topic yet. *3. License* To use this feature, we need to add license of zstd and zstd-jni to the project. (Thanks to Viktor Somogyi for raising this issue!) It seems like what Apache Spark did would be a good example but there has been no discussion yet. You can find the details of the above issues in the KIP document. Please have a look when you are free, and give me feedback. All kinds of participating are welcome. Best, Dongjin [^1]: At the time of writing, commit 6b4fb8152. On Sat, Jul 14, 2018 at 10:45 PM Dongjin Lee <dong...@apache.org> wrote: > Sorry for the late reply. > > In short, I could not submit the updated KIP by the feature freeze > deadline of 2.0.0. For this reason, it will not be included in the 2.0.0 > release and all discussion for this issue were postponed after the release > of 2.0.0. > > I have been updating the PR following recent updates. Just now, I rebased > it against the latest trunk and updated the zstd version into 1.3.5. If you > need some request, don't hesitate to notify me. (But not this thread - just > send me the message directly.) > > Best, > Dongjin > > On Tue, Jul 10, 2018 at 11:57 PM Bobby Evans <bo...@apache.org> wrote: > >> I there any update on this. The performance improvements are quite >> impressive and I really would like to stop forking kafka just to get this >> in. >> >> Thanks, >> >> Bobby >> >> On Wed, Jun 13, 2018 at 8:56 PM Dongjin Lee <dong...@apache.org> wrote: >> >> > Ismael, >> > >> > Oh, I forgot all of you are on working frenzy for 2.0! No problem, take >> > your time. I am also working at another issue now. Thank you for >> letting me >> > know. >> > >> > Best, >> > Dongjin >> > >> > On Wed, Jun 13, 2018, 11:44 PM Ismael Juma <isma...@gmail.com> wrote: >> > >> > > Sorry for the delay Dongjin. Everyone is busy finalising 2.0.0. This >> KIP >> > > seems like a great candidate for 2.1.0 and hopefully there will be >> more >> > of >> > > a discussion next week. :) >> > > >> > > Ismael >> > > >> > > On Wed, 13 Jun 2018, 05:17 Dongjin Lee, <dong...@apache.org> wrote: >> > > >> > > > Hello. I just updated my draft implementation: >> > > > >> > > > 1. Rebased to latest trunk (commit 5145d6b) >> > > > 2. Apply ZStd 1.3.4 >> > > > >> > > > You can check out the implementation from here >> > > > <https://github.com/apache/kafka/pull/2267>. If you experience any >> > > problem >> > > > running it, don't hesitate to give me a mention. >> > > > >> > > > Best, >> > > > Dongjin >> > > > >> > > > On Tue, Jun 12, 2018 at 6:50 PM Dongjin Lee <dong...@apache.org> >> > wrote: >> > > > >> > > > > Here is the short conclusion about the license problem: *We can >> use >> > > zstd >> > > > > and zstd-jni without any problem, but we need to include their >> > license, >> > > > > e.g., BSD license.* >> > > > > >> > > > > Both of BSD 2 Clause License & 3 Clause License requires to >> include >> > the >> > > > > license used, and BSD 3 Clause License requires that the name of >> the >> > > > > contributor can't be used to endorse or promote the product. >> That's >> > it >> > > > > < >> > > > >> > > >> > >> http://www.mikestratton.net/2011/12/is-bsd-license-compatible-with-apache-2-0-license/ >> > > > > >> > > > > - They are not listed in the list of prohibited licenses >> > > > > <https://www.apache.org/legal/resolved.html#category-x> also. >> > > > > >> > > > > Here is how Spark did for it >> > > > > <https://issues.apache.org/jira/browse/SPARK-19112>: >> > > > > >> > > > > - They made a directory dedicated to the dependency license files >> > > > > <https://github.com/apache/spark/tree/master/licenses> and added >> > > > licenses >> > > > > for Zstd >> > > > > < >> > https://github.com/apache/spark/blob/master/licenses/LICENSE-zstd.txt >> > > > >> > > > & >> > > > > Zstd-jni >> > > > > < >> > > > >> > > >> > >> https://github.com/apache/spark/blob/master/licenses/LICENSE-zstd-jni.txt >> > >> > > > > . >> > > > > - Added a link to the original license files in LICENSE. >> > > > > <https://github.com/apache/spark/pull/18805/files> >> > > > > >> > > > > If needed, I can make a similar update. >> > > > > >> > > > > Thanks for pointing out this problem, Viktor! Nice catch! >> > > > > >> > > > > Best, >> > > > > Dongjin >> > > > > >> > > > > >> > > > > >> > > > > On Mon, Jun 11, 2018 at 11:50 PM Dongjin Lee <dong...@apache.org> >> > > wrote: >> > > > > >> > > > >> I greatly appreciate your comprehensive reasoning. so: +1 for b >> > until >> > > > now. >> > > > >> >> > > > >> For the license issues, I will have a check on how the over >> projects >> > > are >> > > > >> doing and share the results. >> > > > >> >> > > > >> Best, >> > > > >> Dongjin >> > > > >> >> > > > >> On Mon, Jun 11, 2018 at 10:08 PM Viktor Somogyi < >> > > > viktorsomo...@gmail.com> >> > > > >> wrote: >> > > > >> >> > > > >>> Hi Dongjin, >> > > > >>> >> > > > >>> A couple of comments: >> > > > >>> I would vote for option b. in the "backward compatibility" >> section. >> > > My >> > > > >>> reasoning for this is that users upgrading to a zstd compatible >> > > version >> > > > >>> won't start to use it automatically, so manual reconfiguration >> is >> > > > >>> required. >> > > > >>> Therefore an upgrade won't mess up the cluster. If not all the >> > > clients >> > > > >>> are >> > > > >>> upgraded but just some of them and they'd start to use zstd >> then it >> > > > would >> > > > >>> cause errors in the cluster. I'd like to presume though that >> this >> > is >> > > a >> > > > >>> very >> > > > >>> obvious failure case and nobody should be surprised if it didn't >> > > work. >> > > > >>> I wouldn't choose a. as I think we should bump the fetch and >> > produce >> > > > >>> requests if it's a change in the message format. Moreover if >> some >> > of >> > > > the >> > > > >>> producers and the brokers are upgraded but some of the consumers >> > are >> > > > not, >> > > > >>> then we wouldn't prevent the error when the old consumer tries >> to >> > > > consume >> > > > >>> the zstd compressed messages. >> > > > >>> I wouldn't choose c. either as I think binding the compression >> type >> > > to >> > > > an >> > > > >>> API is not so obvious from the developer's perspective. >> > > > >>> >> > > > >>> I would also prefer to use the existing binding, however we must >> > > > respect >> > > > >>> the licenses: >> > > > >>> "The code for these JNI bindings is licenced under 2-clause BSD >> > > > license. >> > > > >>> The native Zstd library is licensed under 3-clause BSD license >> and >> > > > GPL2" >> > > > >>> Based on the FAQ page >> > > > >>> https://www.apache.org/legal/resolved.html#category-a >> > > > >>> we may use 2- and 3-clause BSD licenses but the Apache license >> is >> > not >> > > > >>> compatible with GPL2. I'm hoping that the "3-clause BSD license >> and >> > > > GPL2" >> > > > >>> is really not an AND but an OR in this case, but I'm no lawyer, >> > just >> > > > >>> wanted >> > > > >>> to make the point that we should watch out for licenses. :) >> > > > >>> >> > > > >>> Regards, >> > > > >>> Viktor >> > > > >>> >> > > > >>> >> > > > >>> On Sun, Jun 10, 2018 at 3:02 AM Ivan Babrou <ibob...@gmail.com> >> > > wrote: >> > > > >>> >> > > > >>> > Hello, >> > > > >>> > >> > > > >>> > This is Ivan and I still very much support the fact that zstd >> > > > >>> compression >> > > > >>> > should be included out of the box. >> > > > >>> > >> > > > >>> > Please think about the environment, you can save quite a lot >> of >> > > > >>> hardware >> > > > >>> > with it. >> > > > >>> > >> > > > >>> > Thank you. >> > > > >>> > >> > > > >>> > On Sat, Jun 9, 2018 at 14:14 Dongjin Lee <dong...@apache.org> >> > > wrote: >> > > > >>> > >> > > > >>> > > Since there are no responses for a week, I decided to >> > reinitiate >> > > > the >> > > > >>> > > discussion thread. >> > > > >>> > > >> > > > >>> > > >> > > > >>> > > >> > > > >>> > >> > > > >>> >> > > > >> > > >> > >> https://cwiki.apache.org/confluence/display/KAFKA/KIP-110%3A+Add+Codec+for+ZStandard+Compression >> > > > >>> > > >> > > > >>> > > This KIP is about to introduce ZStandard Compression into >> > Apache >> > > > >>> Kafka. >> > > > >>> > > The reason why it is posted again has a story: It was >> > originally >> > > > >>> posted >> > > > >>> > to >> > > > >>> > > the dev mailing list more than one year ago but since it >> has no >> > > > >>> > performance >> > > > >>> > > report included, it was postponed later. But Some people >> > > (including >> > > > >>> Ivan) >> > > > >>> > > reported excellent performance report with the draft PR, >> this >> > > work >> > > > >>> is now >> > > > >>> > > reactivated. >> > > > >>> > > >> > > > >>> > > The updated KIP document includes some expected problems and >> > > their >> > > > >>> > > candidate alternatives. Please have a look when you are >> free, >> > and >> > > > >>> give >> > > > >>> > me a >> > > > >>> > > feedback. All kinds of participating are welcome. >> > > > >>> > > >> > > > >>> > > 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 >> > > > >> <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 >> > > > > <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 >> > > > <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 >> <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 <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>*
