35 ms·

Don't use Java 7 for anything, unless you have no loops in your program

139 points by suprgeek 15y ago

jpr 15y ago
Good, loops are just gotos in disguise, and gotos are already banned in Java. This just makes the language more consistent.
- jpr 15y ago
  Gah, I didn't remember that Java programmers have no sense of humor.
  - jamesaguilar 15y ago
    Sometimes our jokes aren't as funny as we think they will be. :(
  - Confusion 15y ago
    Jokes that many members could come up with have no place on Hacker News. That's the road to devolving into a community where everyone tries to out-joke each other and the actual insightful comments get buried under the jokes. Just grin at the thought and enjoy the happiness, but don't post it. It's not that it's not funny; it's just that it is too easy a comment.
- 9ec4c12949a4f3 15y ago
  GOTO doesn't exist? Good sir, I think you're forgetting how to abuse break statements.
drivebyacct2 15y ago
This blog format is absurd. Narrow column and a fixed width content in a box guaranteed to be smaller than the content. Plus this is effectively blog spam despite being owned by the same place as the original content: http://www.lucidimagination.com/search/document/1a0d3986e48a9348/warning_index_corruption_and_crashes_in_apache_lucene_core_apache_solr_with_java_7 http://www.lucidimagination.com/search/document/1a0d3986e48a...
- asg 15y ago
  Here's the original source for Uwe's email: http://mail-archives.apache.org/mod_mbox/www-announce/201107.mbox/%3C001601cc4d6b$37618880$a6249980$@apache.org%3E http://mail-archives.apache.org/mod_mbox/www-announce/201107... Not sure why a third level reference is being passed around.
  - drivebyacct2 15y ago
    Oh great, so I was still using some gated linked. Thanks for the original, it's even easier on the eyes than my source anyway.
cageface 15y ago
This seems like the sort of thing that should have been caught in automated testing.
- perlgeek 15y ago
  Also if I were to release a new version of a compiler and VM for a widely used language, I'd try to run some really big projects on top of it and see if they work fine. There's no luck of those in Java world.
jbellis 15y ago
Workaround: run with -XX:-UseLoopPredicate. (http://mail.openjdk.java.net/pipermail/hotspot-compiler-dev/2011-July/005971.html http://mail.openjdk.java.net/pipermail/hotspot-compiler-dev/...) But yeah, pretty bad bug.
- rcmuir 15y ago
  low priority actually: http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=7070134 http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=7070134
firemanx 15y ago
This seems fishy to me. I actually got this message as well, and we're evaluating the impact - but this is a tremendously serious and obvious bug to appear in a shipping release of one of the most used softwares on the planet. It just doesn't add up to me. Does anyone have more details than this message?
deleted 15y ago
[deleted]
redthrowaway 15y ago
Text of Uwe's message for anyone who was as annoyed by that text box as I was: From: Uwe Schindler Date: Thu, 28 Jul 2011 23:13:36 +0200 Subject: [WARNING] Index corruption and crashes in Apache Lucene Core / Apache Solr with Java 7 Hello Apache Lucene & Apache Solr users, Hello users of other Java-based Apache projects, Oracle released Java 7 today. Unfortunately it contains hotspot compiler optimizations, which miscompile some loops. This can affect code of several Apache projects. Sometimes JVMs only crash, but in several cases, results calculated can be incorrect, leading to bugs in applications (see Hotspot bugs 7070134 [1], 7044738 [2], 7068051 [3]). Apache Lucene Core and Apache Solr are two Apache projects, which are affected by these bugs, namely all versions released until today. Solr users with the default configuration will have Java crashing with SIGSEGV as soon as they start to index documents, as one affected part is the well-known Porter stemmer (see LUCENE-3335 [4]). Other loops in Lucene may be miscompiled, too, leading to index corruption (especially on Lucene trunk with pulsing codec; other loops may be affected, too - LUCENE-3346 [5]). 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 [6]). This means you cannot use Apache 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 option to not risk index corruptions. Please note: Also Java 6 users are affected, if they use one of those JVM options, which are not enabled by default: -XX:+OptimizeStringConcat or -XX:+AggressiveOpts It is strongly recommended not to use any hotspot optimization switches in any Java version without extensive testing! In case you upgrade to Java 7, remember that you may have to reindex, as the unicode version shipped with Java 7 changed and tokenization behaves differently (e.g. lowercasing). For more information, read JRE_VERSION_MIGRATION.txt in your distribution package! On behalf of the Lucene project, Uwe [1] http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=7070134 http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=7070134 [2] http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=7044738 http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=7044738 [3] http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=7068051 http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=7068051 [4] https://issues.apache.org/jira/browse/LUCENE-3335 https://issues.apache.org/jira/browse/LUCENE-3335 [5] https://issues.apache.org/jira/browse/LUCENE-3346 https://issues.apache.org/jira/browse/LUCENE-3346 [6] http://s.apache.org/StQ http://s.apache.org/StQ
koevet 15y ago
Great way to boost the confidence of the community in Oracle handling Java...
- jandevos 15y ago
  It'll be the way they handle this bug that will make/break my confidence. If they fix this quickly enough (even though they have this bug set to a low priority right now) then I won't mind too much.
gjm11 15y ago
"These problems were detected only 5 days before the official Java 7 release, so Oracle had no time to fix those bugs" -- this is very, very broken. They had time to not release a version of Java with known wrong-code and crashing bugs affecting real code.
- smcj 15y ago
  Mitigation would just have required to make an optimizer option non-default, like in 6.
- tmcw 15y ago
  For sure. Though, I was impressed that he got through every paragraph without even a hint of the snark that this deserves.
anonymous 15y ago
Oracle will kill Java
- speckledjim 15y ago
  You cannot kill a language, unless everyone stops using it. The chances of that are nil. But keep on with the hyperbole.
- locopati 15y ago
  Sun had exactly the same problems with major Java releases (see my comment up-thread).
speckledjim 15y ago
More generally, don't use anything on the day of release... Wait a week or 2 for the bugs to be ironed out. Surely we've all learnt that by now...
- locopati 15y ago
  Certainly with Java (speaking from experience going back to 1.0) and most certainly with major language/compiler releases like this one (see 1.5 previously). Java almost always requires a dot-release or two after a major version to iron out the kinks. Which isn't to say don't try it, but try it in development with low expectations. On the other hand, they're usually very quick about turning out the next few dot-releases (I'd wager that it'll be 1.7.3 by September, unless they continue with the silly 1.6.0_xx version format in which case 1.7.0_03).
js2 15y ago
Disaggregated link - http://mail-archives.apache.org/mod_mbox/www-announce/201107.mbox/%3C001601cc4d6b$37618880$a6249980$@apache.org%3E http://mail-archives.apache.org/mod_mbox/www-announce/201107...
nvarsj 15y ago
Smells a bit like FUD to me. We've been using openjdk 7 in production for quite a while now with no problems. This is on million+ LOC applications using various open source software (however, not Lucene or Solr :-)). I suggest if you're worried, test it and see what happens. This bug sounds like it will hit you immediately if there is a problem.

139 points by suprgeek 15y ago

jpr 15y ago

Good, loops are just gotos in disguise, and gotos are already banned in Java. This just makes the language more consistent.

jpr 15y ago
Gah, I didn't remember that Java programmers have no sense of humor.
- jamesaguilar 15y ago
  Sometimes our jokes aren't as funny as we think they will be. :(
- Confusion 15y ago
  Jokes that many members could come up with have no place on Hacker News. That's the road to devolving into a community where everyone tries to out-joke each other and the actual insightful comments get buried under the jokes. Just grin at the thought and enjoy the happiness, but don't post it. It's not that it's not funny; it's just that it is too easy a comment.
9ec4c12949a4f3 15y ago
GOTO doesn't exist? Good sir, I think you're forgetting how to abuse break statements.

drivebyacct2 15y ago

This blog format is absurd. Narrow column and a fixed width content in a box guaranteed to be smaller than the content. Plus this is effectively blog spam despite being owned by the same place as the original content: http://www.lucidimagination.com/search/document/1a0d3986e48a9348/warning_index_corruption_and_crashes_in_apache_lucene_core_apache_solr_with_java_7 http://www.lucidimagination.com/search/document/1a0d3986e48a...

asg 15y ago
Here's the original source for Uwe's email: http://mail-archives.apache.org/mod_mbox/www-announce/201107.mbox/%3C001601cc4d6b$37618880$a6249980$@apache.org%3E http://mail-archives.apache.org/mod_mbox/www-announce/201107... Not sure why a third level reference is being passed around.
- drivebyacct2 15y ago
  Oh great, so I was still using some gated linked. Thanks for the original, it's even easier on the eyes than my source anyway.

cageface 15y ago

This seems like the sort of thing that should have been caught in automated testing.

perlgeek 15y ago
Also if I were to release a new version of a compiler and VM for a widely used language, I'd try to run some really big projects on top of it and see if they work fine. There's no luck of those in Java world.

jbellis 15y ago

Workaround: run with -XX:-UseLoopPredicate. (http://mail.openjdk.java.net/pipermail/hotspot-compiler-dev/2011-July/005971.html http://mail.openjdk.java.net/pipermail/hotspot-compiler-dev/...) But yeah, pretty bad bug.

rcmuir 15y ago
low priority actually: http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=7070134 http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=7070134

firemanx 15y ago

This seems fishy to me. I actually got this message as well, and we're evaluating the impact - but this is a tremendously serious and obvious bug to appear in a shipping release of one of the most used softwares on the planet. It just doesn't add up to me. Does anyone have more details than this message?

deleted 15y ago

[deleted]

redthrowaway 15y ago

Text of Uwe's message for anyone who was as annoyed by that text box as I was: From: Uwe Schindler Date: Thu, 28 Jul 2011 23:13:36 +0200 Subject: [WARNING] Index corruption and crashes in Apache Lucene Core / Apache Solr with Java 7 Hello Apache Lucene & Apache Solr users, Hello users of other Java-based Apache projects, Oracle released Java 7 today. Unfortunately it contains hotspot compiler optimizations, which miscompile some loops. This can affect code of several Apache projects. Sometimes JVMs only crash, but in several cases, results calculated can be incorrect, leading to bugs in applications (see Hotspot bugs 7070134 [1], 7044738 [2], 7068051 [3]). Apache Lucene Core and Apache Solr are two Apache projects, which are affected by these bugs, namely all versions released until today. Solr users with the default configuration will have Java crashing with SIGSEGV as soon as they start to index documents, as one affected part is the well-known Porter stemmer (see LUCENE-3335 [4]). Other loops in Lucene may be miscompiled, too, leading to index corruption (especially on Lucene trunk with pulsing codec; other loops may be affected, too - LUCENE-3346 [5]). 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 [6]). This means you cannot use Apache 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 option to not risk index corruptions. Please note: Also Java 6 users are affected, if they use one of those JVM options, which are not enabled by default: -XX:+OptimizeStringConcat or -XX:+AggressiveOpts It is strongly recommended not to use any hotspot optimization switches in any Java version without extensive testing! In case you upgrade to Java 7, remember that you may have to reindex, as the unicode version shipped with Java 7 changed and tokenization behaves differently (e.g. lowercasing). For more information, read JRE_VERSION_MIGRATION.txt in your distribution package! On behalf of the Lucene project, Uwe [1] http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=7070134 http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=7070134 [2] http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=7044738 http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=7044738 [3] http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=7068051 http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=7068051 [4] https://issues.apache.org/jira/browse/LUCENE-3335 https://issues.apache.org/jira/browse/LUCENE-3335 [5] https://issues.apache.org/jira/browse/LUCENE-3346 https://issues.apache.org/jira/browse/LUCENE-3346 [6] http://s.apache.org/StQ http://s.apache.org/StQ

koevet 15y ago

Great way to boost the confidence of the community in Oracle handling Java...

jandevos 15y ago
It'll be the way they handle this bug that will make/break my confidence. If they fix this quickly enough (even though they have this bug set to a low priority right now) then I won't mind too much.

gjm11 15y ago

"These problems were detected only 5 days before the official Java 7 release, so Oracle had no time to fix those bugs" -- this is very, very broken. They had time to not release a version of Java with known wrong-code and crashing bugs affecting real code.

smcj 15y ago
Mitigation would just have required to make an optimizer option non-default, like in 6.
tmcw 15y ago
For sure. Though, I was impressed that he got through every paragraph without even a hint of the snark that this deserves.

anonymous 15y ago

Oracle will kill Java

speckledjim 15y ago
You cannot kill a language, unless everyone stops using it. The chances of that are nil. But keep on with the hyperbole.
locopati 15y ago
Sun had exactly the same problems with major Java releases (see my comment up-thread).

speckledjim 15y ago

More generally, don't use anything on the day of release... Wait a week or 2 for the bugs to be ironed out. Surely we've all learnt that by now...

locopati 15y ago
Certainly with Java (speaking from experience going back to 1.0) and most certainly with major language/compiler releases like this one (see 1.5 previously). Java almost always requires a dot-release or two after a major version to iron out the kinks. Which isn't to say don't try it, but try it in development with low expectations. On the other hand, they're usually very quick about turning out the next few dot-releases (I'd wager that it'll be 1.7.3 by September, unless they continue with the silly 1.6.0_xx version format in which case 1.7.0_03).

js2 15y ago

Disaggregated link - http://mail-archives.apache.org/mod_mbox/www-announce/201107.mbox/%3C001601cc4d6b$37618880$a6249980$@apache.org%3E http://mail-archives.apache.org/mod_mbox/www-announce/201107...

nvarsj 15y ago

Smells a bit like FUD to me. We've been using openjdk 7 in production for quite a while now with no problems. This is on million+ LOC applications using various open source software (however, not Lucene or Solr :-)). I suggest if you're worried, test it and see what happens. This bug sounds like it will hit you immediately if there is a problem.