I also feel that the primary usage of the internal messaging in Lucene
today is debugging, and we don't need a logging framework for that.
Mike
Doug Cutting wrote:
The infoStream stuff goes back to 1997, before there was log4j or any
other Java logging framework.
There's never been a big push to add logging to Lucene. It would
add a dependency, and Lucene's jar has always been standalone, which
is nice. Dependencies can conflict. If Lucene requires one version
of a dependency, then it may not work well with code that require a
different version of that dependency.
And it hasn't been clear which framework to adopt. Log4j is the
granddaddy, then there's Java logging and commons logging. Today
the preferred framework is probably SLF4J. Good thing we didn't
choose the wrong one years ago!
And how many log entries would folks really want to see per query or
document indexed? In production I don't think most folks want to
see more than one entry per query or document indexed. So finer-
grained logging would be for debugging. For that one can instead
use a debugger. Hence the traditional lack of demand for detailed
logging in Lucene.
That's the history as I recall it. The future is less clear.
Doug
Grant Ingersoll wrote:
I think the main motivation has always been to have no dependencies
in the core so as to keep it as fast and lightweight as possible.
Then, of course, there is always the usual religious wars around
which logging framework to use, not to mention the nightmare that
is trying to manage multiple logging frameworks across several
projects that are being integrated. Then, of course, there is the
question of how useful any core Lucene logs would be to users
writing search applications. For the most part, my experience has
been that I want logging to tell me when a document was added, when
searches occur, etc. but I don't necessarily need to know things
like the fact that Lucene is now entering the analysis phase of
Document inversion. And, for all these needs, I can just as well
do that logging in the application and not in Lucene.
All that is not to say we couldn't add in logging, I'm just
suggesting reasons I can think of for why it has not been added to
date and why I am not sure it needs to be there going forward. I
believe various other people have contributed reasons in the past.
I seem to recall Doug spelling some out, but don't have the thread
handy.
-Grant
On Dec 5, 2008, at 1:17 PM, Shai Erera wrote:
Hi
I was wondering why doesn't the Lucene code uses Java logging,
instead of the infoStream set in IndexWriter? Today, if I want to
enable tracing of Lucene code, the only thing I can do is set an
infoStream, but then I get many many messages. Moreoever, those
messages seem to cover indexing code only.
I hope to get some opinions on the use of Java logging instead of
infoStream, and hopefully to start addind logging messages in
other places in the code (like during search, query parsing etc.)
I feel that this is an approach the community has to decide on
before we start adding messages to the code. Using Java logging
can greatly benefit tracing of indexing applications who use
Lucene. If the vote is +1 for using Java logging, we can start by
deprecating infoStream (in 2.9, remove in 3.0) and use logging
instead.
What do you think?
Shai
---------------------------------------------------------------------
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
---------------------------------------------------------------------
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
---------------------------------------------------------------------
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
