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From "Akihiro Matsukawa (JIRA)" <j...@apache.org>
Subject [jira] [Created] (PIG-3836) Pig signature has has guava version dependency
Date Wed, 26 Mar 2014 20:48:18 GMT
Akihiro Matsukawa created PIG-3836:
--------------------------------------

             Summary: Pig signature has has guava version dependency
                 Key: PIG-3836
                 URL: https://issues.apache.org/jira/browse/PIG-3836
             Project: Pig
          Issue Type: Bug
            Reporter: Akihiro Matsukawa
            Assignee: Akihiro Matsukawa


We currently use Hashing.goodFastHash(32) to generate signatures for the logical plan. Under
the hood, this is a murmur32 hash.

Guava 11, which pig directly depends on, always seeds the hash with 0.

http://docs.guava-libraries.googlecode.com/git-history/v11.0/javadoc/src-html/com/google/common/hash/Hashing.html#line.85

In future versions of Guava, it is seeded by current time: http://docs.guava-libraries.googlecode.com/git-history/v14.0/javadoc/src-html/com/google/common/hash/Hashing.html#line.47

So when future versions of guava is pulled into the classpath (which if often), we no longer
get the same signature for the same logical plan. This introduces unnecessary complexity for
managing the classpath.



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