Sunday, November 04, 2007
Time for a Divorce
That got me to thinking: a lot of us developers use a lot of open source software. How do we choose which packages we want to use? Obviously whatever we choose has to be a good technical fit for our needs... what's the point if it doesn't do the job we're after? But now it occurs to me that open source software has to meet a particular social need as well. One way we can gauge a project's health is by how strong it is socially. How interested are people? Is the project active? Are people excited about the project? Excited enough to fix bugs?
It's a little hard to compare apples to apples in this case, but let's look at a couple things and try to relate them as best we can. Toplink Essentials is maintained as part of the Glassfish project.
In the last 30 days at the time of this writing, the folks working on it have fixed 10 bugs. In that same amount of time, 15 bugs were opened (or changed and left in an opened state). About 53 messages have been posted on the discussion forum. The oldest unresolved bug has been open for about a year and 10 months.
In that same amount of time, the OpenJPA folks have resolved 19 bugs while 20 have been opened. The mailing list has had about 215 posts. The oldest unresolved bug is a year and 4 months old (though it was touched 3 months ago). OpenJPA is using Jira which makes it a bit easier to produce meaningful metrics such that we can find that the average unresolved age of a bug in the last month is about 3 months, which has been fairly consistent.
(I gave up trying to compute the average unresolved age of bugs for Toplink Essentials. It's just too annoying to figure out if the bug tracking tool doesn't do it for you.)
It is probably the case that most open source projects (and probably closed ones too) have a few ancient bugs gathering dust. I think that it's more interesting to look at what a project has been doing recently, like in the last 30-180 days. Are they keeping up with their bug backlog? Is there an active community? Are you likely to get help if you ask for it? Of the bugs that come in, what percentage get fixed and what percentage get dumped in the attic?
And perhaps the most important criteria of all: are they fixing MY bug?
While I wasn't watching, OpenJPA reached a 1.0.0 release. It's available under the Apache 2 license from a Maven 2 repository. They fixed the bug I opened earlier this year (within a day even). It is full-featured and even has an extensive manual. Though, like Toplink, their ant task doesn't work very well.
I used to be concerned about the large number of dependencies that OpenJPA has, but now that the project is building with Maven 2, it's much less of a concern for me. It isn't necessary to go manually fetch anything to build the project, since Maven 2 takes care of all the direct and transitive dependencies. One thing I did have to manually tweak was to force inclusion of commons-collections 3.2 in my pom.xml, because something else in my project depends on an earlier version of commons-collections, and OpenJPA needs a later version.
So it's time to give Toplink one final heave-ho. My reasons for sticking with it have now been outweighed by my need of having compile-time weaving that works and a project where problems are likely to be fixed within my lifetime. It's time for Toplink and I to start seeing other people.
New releases of Tally-Ho will be using OpenJPA as the persistence provider... just as soon as I get all the unit tests passing.
Tuesday, March 06, 2007
Toplink Essentials: Not Ready for Prime Time
I wish I could say the same for Toplink Essentials. It feels like the open source branching was done as a rush-job, leaving large portions of the necessary code and tooling undone. My simple test case to take advantage of "weaving" (bytecode instrumentation) fails. My attempt to make the instrumentation work using static weaving (post-compile and pre-run) also fails, but in a different way. These are not elaborate test cases. My code isn't terribly complex yet, and my schema is fairly straightforward. Yet Toplink falls down and goes splat. Some of their tools can't even handle spaces in the pathname.
For now I'll keep using OpenJPA until the Glassfish people can make Toplink Essentials stop sucking so damn much. OpenJPA is a bit more pedantic anyway, and that's a good thing. My code should end up tighter as a result.
Much of this JPA stuff just isn't ready for the real world yet, though it's been a final spec since last May and a proposed final draft since December of 2005. They don't even have support for @OneToOne in Eclipse WTP 2.0 yet, and every edit to the persistence.xml file brings up some lame dialog box whining about a ConcurrentModificationException. Granted, it's just a milestone build. But this is the type of frustration one encounters when trying to use JPA.
And no, I'm not going to use sucky Hibernate and their dozens of goddamn dependencies, lack of integrated object caching, and mental-defective nerd community.
Sunday, March 04, 2007
Open JPA Can't @OrderBy a Related Object's @Id
I just can't win tonight.
UPDATE: it turns out that @OrderBy with no options means to order by the identity value of the related object, and this does work correctly in OpenJPA.
Toplink's Weaving is Broken
Or rather, it's not doing it very effectively, if I may overload usage of the word, because it's totally broken in a very simple and stupid way which even a primitive test case should reveal. It fails to correctly instrument put field operation for a field that has an associated Entity. In this case, that means that when I try to set my MessageRoot on my Message, I get this:
As you can probably imagine, I did not write a method called _toplink_setroot. The problem is, neither did Toplink, even though it should have.
Since the Toplink instrumentation code doesn't appear to do any logging of any kind, it is utterly impossible to debug this problem. I have exactly nothing at all to go on, other than the name of a method that doesn't exist, which Toplink should have supplied if it wanted to call it.
Much as I wanted to use Toplink for this project, this problem is a complete deal-breaker. What's particularly startling to me is that such a simple test case can fail without anyone noticing.
Next I guess I'll try BEA's Open JPA (Kodo) and see if they can manage to do proper lazy loading of a 1:1 relationship AND let me create that relationship too... since that's too much to ask of Toplink.
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