[jboss-as7-dev] Changed arguments…can we do better ? :P

[Andrew Dinn]

On 02/01/2012 03:29 PM, Max Rydahl Andersen wrote:
>> Yes. If you don't add this at startup then the module loader will hide
>> all the Byteman classes from all JBoss classloaders. This means that you
>> cannot decide to install a Byteman agent after AS startup in order to
>> debug/trace behaviour in a broken App Server. It just won't work (TM).
>> That's going to give our support team (not to mention our developers who
>> need to use Byteman for testing) a major headache.
>
> Yes, I know - same problem for those wanting to use jprofiler, yourkit, eclemma, and others.

No, it's not actually the same at all. Very far from it.

With jprofiler etc you know in advance that you want to profile your 
program run or whatever. With byteman you don't know until something 
goes wrong that you might need to load the Byteman agent, install some 
trace rules and see what is going wrong. Most customers don't even know 
that this is an option. However, our support team do and regularly use 
it to talk customers through problems which arise in both sandbox and 
live installs. Without this preliminary step the customer has to stop 
and restart the AS in order to load the Byteman agent and Byteman rules 
and this often means that the problem goes away -- i.e. important 
support opportunity lost.

Anyway, I don't really need to convince you of this. Our support team 
have already convinced *me* that this is a vital config option. If you 
want to remove this on the grounds that it is just like all these other 
cases I suggest you talk them first. Otherwise when the support problems 
start piling up you are definitely not going to be Mr Popular.

> Yes, I just suggest we make this list include more than just byteman and
> take it *off* the commandline into a setting.

It is a setting already. The fact that it is set using a shell script 
doesn't really change that. If you want to argue for an alternative 
control well, I'll leave that to our usability experts.

>> Also, I think the idea of adding this via a properties file sounds nice
>> at first but actually it is just splitting up the config by another
>> name. One file to rule them all . . .
>
> The problem is there are not one file to rule them all.
>
> There is one per OS  and tools that need to launch cannot use the .bat/.sh files
> since no way to portably and reliably kill the process.

There is one file to rule them all as far as the normal startup 
mechanism is concerned. At least that's precisely how Jason described it 
some months back -- unless, perhaps, he has changed his mind?

That may not be of any help to you if you are starting the AS by other 
means but surely you can provide equivalent configuration options and an 
API to configure them. In which case just be sure to include this in 
your default config. It may not be so important to your usrs but I 
suspect that is not the case.

regards,


Andrew Dinn
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