On Sat, Jul 30, 2011 at 08:34, Fabrizio Giudici
<[email protected]> wrote:
> 1. Were these loop-breaking optimizations introduced by default only in
> 7.0GA - so they weren't in betas?
> 2. If answer#1 is "no", did they try Lucene with betas?

I was able to find some more info and it turns out that:

1. that Oracle learned about it 5 days before GA release, and promised
a fix for the first JDK7 security update

2. that Java 6 users are also affected, if they enable
-XX:+OptimizeStringConcat or -XX:+AggressiveOpts
http://pages.citebite.com/d9y2u1i5bnjm

3. That this doom and gloom bug (according to tweets) actually affects
very specific conditions, and there is a work-around. In the words of
the poster:

-----
> These problems were detected only 5 days before the official Java 7 release, 
> so Oracle had no time to fix those bugs, affecting also many more
> applications. In response to our questions, they proposed to include the 
> fixes into service release u2 (eventually into service release u1, see
> [http://mail.openjdk.java.net/pipermail/hotspot-compiler-dev/2011-July/005971.html]).
> This means you cannot use Lucene/Solr with Java 7 releases before Update 2! 
> If you do, please don't open bug reports, it is not the committers' fault! At 
> least disable loop optimizations using the -XX:-UseLoopPredicate JVM options
-----

4. As usual h-online has some of the best, in-depth reporting when it
comes to Java, without apocalypse headlines that I´m sure will appear
in other sites like TheReg...

Java 7 paralyses Lucene and Solr
http://www.h-online.com/open/news/item/Java-7-paralyses-Lucene-and-Solr-1288210.html

5. "Don´t use Java 7 for *anything*" seems to me like just bad faith,
specially given the availability of a work-around (point #3 above).

6. I wonder if, in situations like this, it wouldn´t be possible just
to issue a 7.01 that runs with the work-around parameter (
-XX:-UseLoopPredicate ) all the time, whether present and passed by
the user or not.

FC

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