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>*
