What is the nature of the single LCF process issue? Is it because the
database is being used in single-user mode, or some other issue? Is it a
permanent issue, or is there a solution or workaround anticipated at some
stage.
Thanks.
-- Jack Krupansky
--------------------------------------------------
From: <karl.wri...@nokia.com>
Sent: Thursday, June 03, 2010 5:34 PM
To: <connectors-dev@incubator.apache.org>
Subject: Derby
For what it's worth, after some 5 days of work, and a couple of schema
changes to boot, LCF now runs with Derby.
Some caveats:
(1) You can't run more than one LCF process at a time. That means you
need to either run the daemon or the crawler-ui web application, but you
can't run both at the same time.
(2) I haven't tested every query, so I'm sure there are probably some
that are still broken.
(3) It's slow. Count yourself as fortunate if it runs 1/5 the rate of
Postgresql for you.
(4) Transactional integrity hasn't been evaluated.
(5) Deadlock detection and unique constraint violation detection is
probably not right, because I'd need to cause these errors to occur before
being able to key off their exception messages.
(6) I had to turn off the ability to sort on certain columns in the
reports - basically, any column that was represented as a large character
field.
Nevertheless, this represents an important milestone on the path to being
able to write some kind of unit tests that have at least some meaning.
If you have an existing LCF Postgresql database, you will need to force an
upgrade after going to the new trunk code. To do this, repeat the
"org.apache.lcf.agents.Install" command, and the
"org.apache.lcf.agents.Register
org.apache.lcf.crawler.system.CrawlerAgent" command after deploying the
new code. And, please, let me know of any kind of errors you notice that
could be related to the schema change.
Thanks,
Karl
