I've run into a problem today upgrading from Aries Blueprint 0.3 to 1.0.
It's a little complicated and I just want to drop this somewhere in case
anyone else runs into a similar problem.

I've embedded Liquibase (a database migration tool) in a persistence
bundle I have in my application. It generates check sums from the XML
files defining the database changes to determine if any changes to the
database model are necessary.

I'm also experimenting with Camel and while playing with the
camel-servlet example [1] I've had to add ext:proxy-method="classes" to
the CamelServlet reference since it is an object and not an interface.
But that required to have ASM 4 present so I installed ASM 4.1 (I had
org.apache.servicemix.bundles.asm-3.3_2.jar in there before).

But then Liquibase suddenly began to complain about changed check sums
whenever I started up the persistence bundle. I could delete the
database and restart but would run into the same problem.

In the end, I managed to make the link between the weaving and the check
sum problems. Why exactly this affects the check sums, I haven't checked.
But this is, of course, a question for a different forum. Anyway, I
eventually found out that I can set org.apache.aries.proxy.weaving.disabled=*
in the system properties. I think it would be great if someone could
document that on the Aries website. I've had to sift through the
archives at markmail.org to find Guillaume's ARIES-786. As a nice
side-effect, startup performance is back in the same region as before.
After the Blueprint upgrade, it took much longer.

I was a bit surprised to see that my Camel route that caused me to
upgrade Blueprint in the first place is now still working, although I'm
basically disabling weaving completely. That would suggest that
installing the WeavingHook is actually still unnecessary in my case. So
I'm wondering if a system property (or configuration) to completely
disable the WeavingHook in ProxyManagerActivator wouldn't actually be
useful. Unfortunately, Aries Blueprint seems to require Aries Proxy so I
can't just uninstall the bundle.

[1] http://camel.apache.org/servlet.html

I hope this helps someone some day.

Jeremias Maerki

Reply via email to