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From Steve Loughran <ste...@apache.org>
Subject Re: Append to Files..
Date Wed, 03 Dec 2008 10:30:59 GMT
Tsz Wo (Nicholas), Sze wrote:
> Yes, append is a new feature in 0.19 but not 0.18.
> I think you need a lot of effort to compile 0.19 with Java 5 since the codes use Java
6 APIs.  Switch to Java 6 if possible.

That's an interesting question. I have a private build of Hadoop which 
was built on Java6, with the javac.version set to 1.5, with the output 
being a JAR which is marked as Java-5 compatible. It does build and pass 
my local functional tests on a java5 system -but I havent tried the full 
hadoop test suite. The big risk is that some java class has a new 
feature, like an extra constructor on an exception class (e.g. 
IOException(Throwable), which is a new 6+ constructor). Accordingly, 
even though my JAR will load on 1.5, I say "only deploy hadoop clusters 
on java6+.

why tag the JAR for Java5 then? Two reasons
  -Java 5 clients get to talk to the cluster
  -Our CI servers (Hudson and Cruise Control) are on Java5 to stop us 
accidentally using Java6 features in our own codebase. They need a 
compatible Hadoop JAR

Like I said, It can be done, but you are on your own if you try


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