On Thu, Aug 12, 2010 at 4:19 PM, Scott Carey <[email protected]> wrote: > Yup, Hadoop's jar dependency management is poor. > > I just repackaged hadoop and removed jackson 1.0.1 jar from it, so no slaves > have Jackson in their lib directory. Its only used for the 'dump > configuration in JSON format' feature, which I don't use (and a minor feature > that adds a jar should probably have gotten a lot of scrutiny before adding > the jar/feature). > > Alternatively, since Jackson 1.x is backwards compatible to 1.0, one can > replace 1.0.1 with 1.x.x on the slaves or in the package.
FWIW, it would be good to upgrade Jackson version to something more modern -- incompatibility in question is very unfortunate (and obviously accidental; minor versions should not introduce such incompatibilities), and was caused by changing return type from void to 'this' to allow method chaining (this actually is a major binary incompatibility, but usually not source!) -- but upgrading to a later version would be good anyway because 1.0.x itself is not being maintained. Safest bet would be latest 1.4.x or 1.5.x release. If any issues are found please let me know and I can help. Also: if one really wants to use 1.0.x jar, recompiling code that uses it should be enough to make things work, since specific issue only affects binary compatibility. -+ Tatu +-
