Hi,
I'm trying to port one of the v2 commands onto v3. This is the first
time I'm writing a command in v3 and have some general questions:
1. Is there any document regarding the practices to be followed while
writing commands? Looks like the v3
CLI
spec wasn't updated for the final release and it mainly talks
about features that were dropped. I've seen the v3
engineer's
guide CLI section, but that too contains a very simple
example.
And I would like to know all the secrets for laying down a perfect tile
floor but I can't find a really good book. Why? Because people that
are really good at doing that usually suck at documenting it.
If you are writing a CLI command look at commands written by Bill
Shannon they are as close to perfect as you're likely to find and then
ask specific questions and pass your ideas for early review preferably
to Bill for CLI and to Jerome for remote
Will start to looks at Bill's commands, thanks for the pointer.
2. Where can I find documentation for the various annotations?
Documentation? We don't need no stinkin' documentation! Hint: monkey
see monkey do ;-)
I generated javadocs in glassfish-api, that should suffice for a start.
I will look at code for more details when needed.
3. From what I understand, there are 2 ways to introduce a command, one
is by implementing the AdminCommand interface and other is writing a
CRUD command, is that correct?
Don't even think about implementing a CRUD command unless you run it by
Jerome and know exactly what you're doing. CRUD is designed for things
that have a 1:1 correspondence with elements in domain.xml
"start-instance" is not for CRUD. create-instance IS. CReate
Update Delete. CRUD is designed (successfully) to
stop
the grudge work and unnecessary complexity of many almost-identical
boiler-plated commands.
4. How/when to implement CRUD commands?
See above and more importantly look at the source
5. Whats the best way to debug any command? I made some changes in the
config beans and now DAS isn't even starting, it just hangs after the
launcher message. I'm at loss as to where to look! (Changing felix log
level and admin logging to finest doesn't help since its in the very
intial stage of startup)
QA and Managers use logging levels. Engineers use debuggers and break
points. Set a breakpoint much earlier. Go to ASMain in
core/bootstrap for extremely early debugging and in AppServerStartup
(core/kernel) for "normal" early. Run start-domain with the "--debug"
arg. Edit domain.xml and set 'suspend=y' in the java-options section
then attach to your debugger as it sits there patiently waiting for you.
Not that I don't know how to use the debugger, I was hoping to get some
clue from log messages, thats all. In v2, I know exactly where to set
breakpoints whereas in v3, I don't know how the execution path is for
any admin operation. Anyways, I figured that out by backing out all my
changes and setting breakpoint in CreateHttpListener. Will keep in mind
to look at the above mentioned classes for early debugging.
6. While porting a v2 command, I presume both the files,
supported-legacy-command-names/unsupported-legacy-command-names need to
be updated. Is that correct?
OK -- you have me confused now. This is a question about **CLI**
commands and your other questions sound like Remote AdminCommand's
which is it? both? What are you doing?
Actually both. I'm working on porting one of the load balancer
commands. Next step is to figure out what mistake in my changes causes
the startup hang, will get back in case I need help.
Thanks,
-Yamini