Docs for JENKINS_JAVA_OPTIONS

[Frank Merrow]

I’ve seen several post about increasing Jenkins memory with Jenkins Java Options . . . and also found the <arguments> values in the jenkins.xml file which seem to be similar.

 

What I have NOT found is documentation on any of these . . .

 

What exactly can go in <arguments></arguments>?

 

This is always glibly shown like “oh everyone knows what this means”, but . . . well no they don’t.  (-Xrs . . . what is that?)

 

No, I don’t really want to know what –Xrs does . . . I want to know what all the options are and what they do . . .

 

Googling doesn’t seem to be helping in this case; Jenkins docs probably should be able to help me, but I have yet to find the right page.

 

Anyone know where these are documented?

 

Frank

[Sami Tikka]

These are options for the java virtual machine. What kind of options you want to use and where these are documented depend on the JVM you are using. 

I don't really think it is the job of Jenkins to document the options of JVMs. Jenkins developers cannot know which JVM you choose to run Jenkins. 

Most people probably assume the Sun JVM and it is very popular. But AFAIK it is not the only one around. As you can see, it doesn't make it easy to give exact advice if people do not tell which JVM they are using. Often people also fail to mention which operating system they use. (I know, java is supposed to hide that, but it doesn't)

Some things for you to study:

- Run "java -h" and study its output.

- The same for "java -X"

- And remember, google is your friend. 

-- Sami

[Frank Merrow]

Awesome information Thank you . . .

 

I would have happily given you my JVM version IF I HAD KNOWN that is what I was dealing with . . .

 

Now that I do, I’m guessing I won’t have much problems finding it.

 

THANK YOU.

 

Fran

[Les Mikesell]

On Sun, Mar 4, 2012 at 11:17 AM, Frank Merrow <fme...@gmail.com> wrote:
>
> I would have happily given you my JVM version IF I HAD KNOWN that is what I
> was dealing with . . .
>
>
>
> Now that I do, I’m guessing I won’t have much problems finding it.
>

You should probably find the command that starts jenkins on whatever
platform you are using. Windows and different linux versions will be
somewhat different, but things should be more clear after you see the
current settings and the way they are given.

--
Les Mikesell
lesmi...@gmail.com

[Sami Tikka]

I guess Jenkins is a victim of its own success. Earlier it could be assumed its users knew what it means to run software written in java. Maybe the native installers have done too good a job and now people do not know what they are dealing with. 

Maybe we can do something to remedy the situation? 

Now that I have your attention, maybe you could help me and the rest of the guys who develop the native installers and let us know where you would have wanted to see this documentation? In a readme? A man page? A wiki page? Something else?

Would it be enough to explain you are about to install software that runs on the java virtual machine? With some pointers to where java virtual machines are available and to their documentation?

-- Sami

[Frank Merrow]

I guess in my case, too much new all at once (Java, Jenkins, Groovy) . . . trying to swallow them all in just a couple weeks.

 

I guess I was thrown off by the JENKINS_JAVA_OPTIONS . . . I saw the “Jenkins” part and went looking for documentation in Jenkins about that.  (There is none that I could find.)

 

Now that I  know that it is the “Java Options” for Jenkins, it became obvious I was looking in the wrong place for documentation.

 

A minor difference in focus and in retrospect I might have made the connection myself . . . I just didn’t.

 

The thing is what most folks use Jenkins . . . so my focus was there . . . I was lead to Groovy (and thus Java) in the back door because of Scriptler.

 

You have a unique problem here . . . for example typically I write in C# . . . how often is it that somebody cares that my product is in C#?  Never . . .

 

But then, I don’t exposed a C# scripting interface on those applications . . . suddenly all that would have been important in a new way.

 

As for where I would have expected to see the information . . . Google of course . . . it would have been nice if one of the first few entries in “JENKINS_JAVA_OPTIONS” had lead me to some documentation.

 

Unfortunately, they led me instead to Stack Overflow and other question and answer sites . . . where the it was mentioned in some thread but not explained or documented.

 

The good news . . . at least for the moment, this thread is now #2 on the Google search.  <grin>  Of course they have to read this thread carefully enough to see Java –help and Java –X.

 

And . . . then again, there is another place I would have expected to find it . . . in the Jenkins docs . . . typically available off the Jenkins GUI . . . I find it odd that the “?” up there leads to a description of Jenkins search . . . a nice piece of magic and nice to have the description there, but typically that spot would be reserved for links to documentation about the product . . . They exist, on web sites and such, but not from the GUI that I am aware of.  Oh the question mark leads you to the Wiki, but do you see “documentation” in the legend at the left?  Nope, you have to follow “Home”, then make the leap that “Use Jenkins” it what you want to read . . . even at that level it isn’t immediately obvious there is a user manual in there.

 

Thanks for the info.

 

Frank

[Les Mikesell]

On Sun, Mar 4, 2012 at 4:38 PM, Frank Merrow <fme...@gmail.com> wrote:
>
>
> You have a unique problem here . . . for example typically I write in C# . .
> . how often is it that somebody cares that my product is in C#?  Never . . .
>
>
> But then, I don’t exposed a C# scripting interface on those applications . .
> . suddenly all that would have been important in a new way.

Let me know when you can pull off the magic of auto-installing and
running your C# application as remote slaves across a lot of different
platforms. Sometime the language does matter.

--
Les Mikesell
lesmi...@gmail.com

[Frank Merrow]

>Let me know when you can pull off the magic of auto-installing and running
your C#
>application as remote slaves across a lot of different platforms. Sometime
the language
>does matter.

Religious wars don't interest me . . . if somebody will paid me big bucks to
have fun all day programming . . . I'm happy to let them dictate the
language.

Having said that, I think the real draw to all the .NET languages has
nothing to do with the languages themselves . . . it has to do with the IDE
Visual Studio.

I start typing and a list of the variables and methods "right there" that
are available to me start appearing . . . I see the variable I want (an very
long and expressive name since I know I'll never have to type the whole
thing) and hit "dot" . . . immediately a list of methods and properties
appears that narrows to exactly what I want as I continue to type . . . when
I see what I want I just hit "return" and the 20 character method name is
filled in (even though I only typed four or five characters of it) and the
class docs for the method parameters start appearing in place as I type. I
don't go read class documents, I just hit "dot" and look . . . not sure
which one it is, if I hover over it the class docs for that Method appear.
If there are several overloads, they can also be shown . . . or will
automagically adjust as start I filling in parameters.

It is very addictive . . . amazing how used to Intellisense you can get in
such a short time . . .

Like it or not . . . Microsoft has taking development to a whole now place .
. .

So far, the Java tools that I've seen aren't nearly as "helpful" . . . I you
know of an Java/Groovy IDE that can do even half of what Visual Studios can
. . . please let me know!

Frank

[Les Mikesell]

On Sun, Mar 4, 2012 at 10:01 PM, Frank Merrow <fme...@gmail.com> wrote:
>>Let me know when you can pull off the magic of auto-installing and running
> your C#
>>application as remote slaves across a lot of different platforms.  Sometime
> the language
>>does matter.
>
> Religious wars don't interest me . . . if somebody will paid me big bucks to
> have fun all day programming . . . I'm happy to let them dictate the
> language.

I was referring to specifically to the way jenkins works, not about
whether or not it is fun to write. I don't see a lot of other
languages that offer to self-install and execute across all the
platforms that run jenkins as master or slaves.

> So far, the Java tools that I've seen aren't nearly as "helpful" . . . I you
> know of an Java/Groovy IDE that can do even half of what Visual Studios can
> . . . please let me know!

I think most people use eclipse and its bazillion plugins, but again,
I was talking about the execution and cross-platform capabilities.

--
Les Mikesell
lesmi...@gmail.com

[Frank Merrow]

>I was referring to specifically to the way jenkins works, not about whether
or not it is fun to write.
>I don't see a lot of other languages that offer to self-install and execute
across all the platforms that

>run Jenkins as master or slaves.

And I was pointing out that the IDE support for Java was weak compared to
the Microsoft offerings . . .

I was hoping you'd pipe up and tell me I was wrong "use Xyz" . . . was
Eclipse that recommendation?

The way you phrased it, it didn't sound like you even used it.

Frank

[Les Mikesell]

On Mon, Mar 5, 2012 at 11:44 PM, Frank Merrow <fme...@gmail.com> wrote:
>>I was referring to specifically to the way jenkins works, not about whether
> or not it is fun to write.
>>I don't see a lot of other languages that offer to self-install and execute
> across all the platforms that
>>run Jenkins as master or slaves.
>
> And I was pointing out that the IDE support for Java was weak compared to
> the Microsoft offerings . . .

IDE's don't matter if the resulting code won't run on the platform
where you want it.

> I was hoping you'd pipe up and tell me I was wrong "use Xyz" . . . was
> Eclipse that recommendation?
>
> The way you phrased it, it didn't sound like you even used it.

I'm more of a system administrator that uses perl as much as possible
to avoid dealing with compiler quirks at all, but the java developers
here do use eclipse and I would recommend it - just not from personal
experience. The way it uses plugins makes it sort of a toolbox that
may need some custom setup for exactly the feature set you need,
though. If you have looked at it and thought it was missing
something, you may have just needed a different setup.

--
Les Mikesell
lesmi...@gmail.com