Hi Mickael, Reacting to your points: 1. I think it's somewhat unfortunate that we provide an appender tied to a chosen logger implementation. I think that this shouldn't be part of the project in its current form. However, there is the sl4fj2 Fluent API which may solve our problem and turn KafkaLog4jAppender into a generic implementation that doesn't depend on a specific library given that we can upgrade to slf4j2. That is worth considering. 2. Since KIP-1013 we'd move to Java17 anyways by 4.0, so I don't feel it's a problem if there's a specific dependency that has Java17 as the minimum supported version. As I read though from your email thread with the log4j2 folks, it'll be supported for years to come and log4j3 isn't yet stable. Since we already use log4j2 in our fork, I'm happy to contribute to this, review PRs or drive it if needed.
Thanks, Viktor On Wed, Jan 10, 2024 at 3:58 PM Mickael Maison <mickael.mai...@gmail.com> wrote: > I asked for details about the future of log4j2 on the logging user list: > https://lists.apache.org/thread/6n6bkgwj8tglgdgzz8wxhkx1p1xpwodl > > Let's see what they say. > > Thanks, > Mickael > > On Wed, Jan 10, 2024 at 3:23 PM Ismael Juma <m...@ismaeljuma.com> wrote: > > > > Hi Mickael, > > > > Thanks for starting the discussion and for summarizing the state of > play. I > > agree with you that it would be important to understand how long log4j2 > > will be supported for. An alternative would be sl4fj 2.x and logback. > > > > Ismael > > > > On Wed, Jan 10, 2024 at 2:17 PM Mickael Maison <mickael.mai...@gmail.com > > > > wrote: > > > > > Hi, > > > > > > Starting a new thread to discuss the current logging situation in > > > Kafka. I'll restate everything we know but see the [DISCUSS] Road to > > > Kafka 4.0 if you are interested in what has already been said. [0] > > > > > > Currently Kafka uses SLF4J and reload4j as the logging backend. We had > > > to adopt reload4j in 3.2.0 as log4j was end of life and has a few > > > security issues. > > > > > > In 2020 we adopted KIP-653 to upgrade to log4j2. Due to > > > incompatibilities in the configuration mechanism with log4j/reload4j > > > we decide to delay the upgrade to the next major release, Kafka 4.0. > > > > > > Kafka also currently provides a log4j appender. In 2022, we adopted > > > KIP-719 to deprecate it since we wanted to switch to log4j2. At the > > > time Apache Logging also had a Kafka appender that worked with log4j2. > > > They since deprecated that appender in log4j2 and it is not part of > > > log4j3. [1] > > > > > > Log4j3 is also nearing release but it seems it will require Java 17. > > > The website states Java 11 [2] but the artifacts from the latest 3.0.0 > > > beta are built for Java 17. I was not able to find clear maintenance > > > statement about log4j2 once log4j3 gets released. > > > > > > The question is where do we go from here? > > > We can stick with our plans: > > > 1. Deprecate the appender in the next 3.x release and plan to remove > it in > > > 4.0 > > > 2. Do the necessary work to switch to log4j2 in 4.0 > > > If so we need people to drive these work items. We have PRs for these > > > with hopefully the bulk of the code but they need > > > rebasing/completing/reviewing. > > > > > > Otherwise we can reconsider KIP-653 and/or KIP-719. > > > > > > Assuming log4j2 does not go end of life in the near future (We can > > > reach out to Apache Logging to clarify that point.), I think it still > > > makes sense to adopt it. I would also go ahead and deprecate our > > > appender. > > > > > > Thanks, > > > Mickael > > > > > > 0: https://lists.apache.org/thread/q0sz910o1y9mhq159oy16w31d6dzh79f > > > 1: https://github.com/apache/logging-log4j2/issues/1951 > > > 2: https://logging.apache.org/log4j/3.x/#requirements > > > >
