[OPENJPA-296] UUID algorithm generating non-unique values sometimes

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.9.0, 0.9.6, 0.9.7
• Fix Version/s: 1.0.0
• Component/s: sql
• Assignee: Unassigned
• Reporter: Patrick Linskey
• Created: 25/Jul/07 17:59
• Updated: 09/Mar/10 18:32
• Resolved: 25/Jul/07 18:01

Description

From the dev list:

@Entity
public class Foo

{ @Id @GeneratedValue(strategy=GenerationType.AUTO, generator="uuid-string") private String id; }

CREATE TABLE Foo (
id VARCHAR(16) NOT NULL
}

If I do one em.persist() it works just fine. However, if I do a a whole
list of them, I get exceptions (duplicate). If I enable logging I can
see they are all using the same id during INSERT. I stepped a bit
through the code and noticed that uuid-string doesn't get generated
while em.persist(), but much later while committing/flushing. I then
looked a bit (just a bit) at the UUID generator code and noticed that
the bytes are not changing much (maybe only the first two), but again,
that was while debugging, so I'm assuming I have a supa-fast machine.