I like all your ideas! One thing I have been spending some time is to
how to turn on different levels of logs at different projects (inside of
core geronimo) or other geronimo dependent logs. It would be very nice
if the console can provide that level of details so that a user can just
turn on the logging for the few components they need. Even better, the
system is smart to figure out which components might be interesting for
the specific error, and turn on the logs for the user after the user
requests it via a one click (instead of multiple clicks after figuring
out which components they need to turn on).
Lin
Matt Hogstrom wrote:
Lately I've been working with users in debugging various application
problems. Some of the problems are merely configuration but others are
deeper application / infrastructure problems. Regardless of the type of
problem I've never personally been satisfied with the diagnostic
information produced by the server (this isn't a Geronimo statement but
really AppServers as a whole including WebSphere and WebLogic).
Here are some thoughts that I want to pursue:
I’ve been working with some customers lately and the work has centered
around debugging some of the aspects of their server. In this case it
was using Apache Geronimo but the problem really applies to most
application servers in general. For the most part there is little
diagnostic information available when an application fails. We get the
ever popular nested Java Stack trace which is certainly a good indicator
of where a failure occurred but is woefully inadequate in many instances
of why a failure occurred. This get’s worse in that for the most part
people need to recreate the problem with additional tracing and, in the
worst case, additional diagnostic code in their application. Wouldn’t
it be nice if some of the diagnostic capability that was needed was
included in the server itself?
Over the next few weeks I’m going to be doing some experimentation on
how to improve server diagnostics through the use of Aspects and/or
Instrumentation. Since this is experimental we’ll see what the final
result will be. Here are some of my initial goals:
1. Improve diagnostics by providing a Diagnostic Report when a Tx
fails.
2. Provide better visualization of Java Stack traces so problem areas
pop out.
3. Capture wait information
For number 1 I’m going to focus on servlets to begin with given that
they represent the preponderance of requests made in AppServers today.
This information will include information from the request object, the
servlet being invoked, invocation time, transaction ID (if it exists),
enlisted connections (database and messaging), oh yeah, and the Thread
ID of execution. This is a mouthful to begin with anyway.
Number 2 is really just applying some template information on a Java
Stack trace. I want application classes to standout so developers will
be able to quickly see where their application is involved.
Infrastructure pieces like the server, Hibernate, TopLink, etc. would
also be highlighted in a different color and style and plain old java
classes would be a boring style as their are merely pawns in the
transactional game.
Finally, wouldn’t it be nice to know how long a thread has been waiting
and for what reason? Is it waiting on a request from another server or
perhaps there is a database locking problem. Did a WebService go awry?
Basically, I want to know what in the heck a thread is waiting on.
Please chime in with your thoughts. I spect that Aspects or
Instrumentation may be the only way to go for some of this as many of
the components we include won't have this capability in them.
