So this is all kinds of fun... log4j-core depends on: ....jackson 1.9.11 (optional) log4j-flume-ng depends on: ....flume-ng-sdk 1.3.1 depends on: ........avro 1.7.2 depends on: ............jackson 1.8.8 flume-embedded (sample) depends on: ....flume-ng-sdk 1.3.1 depends on: ........avro 1.7.2 depends on: ............jackson 1.8.8 ....flume-ng-node 1.3.1 depends on: ........jackson 1.9.3
So, we already had three different versions of Jackson in the build: 1.8.8, 1.9.3, and 1.9.11 ... yuck! I took the following steps: 1) I upgraded log4j-core's dependency from 1.9.11 to 2.2.1 without any negative consequences. Everything compiled and all the tests passed. At this point the dependencies were now 1.8.8, 1.9.3, and 2.2.1. 2) I used dependency exclusions to exclude 1.8.8 and got it down to just 1.9.3 and 2.2.1. Everything compiled and all the tests passed. 3) I tried to eliminate 1.9.3 through a further dependency exclusion, but log4j-flume-ng classes didn't load anymore. This indicated that Jackson is NOT an optional dependency of log4j-flume-ng, but instead is a mandatory dependency, which wasn't obvious the way it was set up. 4) I kept the 1.9.3 dependency exclusion but added a mandatory 1.9.11 /runtime/ dependency for log4j-flume-ng. Now everything compiles and all tests pass again, and the Jackson dependencies are limited to the latest minor.patch versions of each major version: 1.9.11 (log4j-flume-ng only, runtime) and 2.2.1 (log4j-core only, compile). Ralph said below "I have no problem upgrading to 2.x so long as it works for both the JSON configuration and Flume." It doesn't work with Flume; Flume requires 1.x. So as a next step we can either: 1) Revert my changes to configuration so that it relies on Jackson 1.9.11 as well and not on 2.2.1. 2) Apply my earlier suggestion that we support both 1.9.11 /and/ 2.2.1 or configuration. 3) Stick with what we have: 1.9.11 for Flume, 2.2.1 for JSON configuration, and no more dependency on 1.8.8. Nick On May 15, 2013, at 7:33 PM, Ralph Goers wrote: > I wrote the JSON support just after the ApacheCon in Vancouver, which I > believe was in 2011. If 2.x was available then it was brand new and the > documentation was slim. I have no problem upgrading to 2.x so long as it > works for both the JSON configuration and Flume (I don't think Flume actually > uses JSON but Avro probably does). Like you, I would prefer not to have two > versions of Jackson in out build. > > Ralph > > > On May 15, 2013, at 11:16 AM, Gary Gregory wrote: > >> I would only support the current version: 2.x. >> >> Gary >> >> >> On Wed, May 15, 2013 at 2:00 PM, Nick Williams >> <nicho...@nicholaswilliams.net> wrote: >> Guys, >> >> Background: Since I'm the lead developer on a Jackson Mapper module >> (https://github.com/FasterXML/jackson-datatype-jsr310), I'm actively >> involved on their development mailing list. >> >> Jackson 1.9 is, well, old. Specifically, 1.9.0 is two years old. 1.9 is the >> last minor version of the 1.x family. There will continue to be bug fixe >> releases—for now—about every 4-6 months. The last patch release was in >> January. >> >> Jackson 2.x is the current version with rapid release periods. 2.0 Is about >> a year old, 2.1 was released in October and 2.2 was released last month. >> Only major bugs will be fixed in 1.9.x. Minor bug fixes and all new features >> will go in 2.x. >> >> Jackson 1.x and 2.x use different Java packages. This has both advantages >> and disadvantages. One advantage is that frameworks and libraries, like >> Spring Framework, can easily support both versions because they can coexist >> on the same class path during compilation and testing. One disadvantage is >> that if some library is using 1.x and some other library is using 2.x and >> you create an application that depends on both libraries, you'll have to >> pull BOTH versions of Jackson on to your class path. Ugh. >> >> Log4j 2 is "brand new" (it's not even released yet). Typically, I would >> argue that new projects should not use old versions of their dependencies. >> In Log4j 2's case, I tend to lean the same direction. It doesn't seem wise >> to tie ourselves to Jackson 1.x so late in its life when Jackson 2.x is >> already mature and Log4j 2 isn't even released yet. As a Java 8, Spring 4, >> Jackson 2 user, I know I wouldn't love having to also have Jackson 1 on my >> class path (if I were using JSON configuration). >> >> I would suggest that we should either support both or we should only support >> 2.x, but only supporting 1.x feels wrong to me. >> >> Supporting both wouldn't be a major challenge. The way Spring does it is to >> have two Jackson* classes and Jackson2* classes with identical APIs. >> Depending on which version you are already using, you use the appropriate >> class. In this case, I would approach it like this: >> >> - Rename JSONConfiguration to Jackson1JSONConfiguration, and (using >> CheckStyle's import control) ensure that only this class imports Jackson 1.x >> - Create a similar class named Jackson2JSONConfiguration, and ensure that >> only this class imports Jackson 2.x >> - Alter JSONConfigurationFactory to detect which version is on the class >> path and return the appropriate JSON configuration, preferring 2.x if both >> are on the class path >> >> Thoughts? >> --------------------------------------------------------------------- >> To unsubscribe, e-mail: log4j-dev-unsubscr...@logging.apache.org >> For additional commands, e-mail: log4j-dev-h...@logging.apache.org >> >> >> >> >> -- >> E-Mail: garydgreg...@gmail.com | ggreg...@apache.org >> Java Persistence with Hibernate, Second Edition >> JUnit in Action, Second Edition >> Spring Batch in Action >> Blog: http://garygregory.wordpress.com >> Home: http://garygregory.com/ >> Tweet! http://twitter.com/GaryGregory > --------------------------------------------------------------------- To unsubscribe, e-mail: log4j-dev-unsubscr...@logging.apache.org For additional commands, e-mail: log4j-dev-h...@logging.apache.org
