Hey,
I have new intel on this. A colleague generated a flame graph.
I cannot share the raw svg unfortunately, but I cropped the Feature JAXB parsing.

It is about 25% of the overall startup time just to boot up the jaxb infrastructure.

Fabian


On Fri, Jul 22, 2016 at 10:06 AM, Fabian Lange <fabian.lange@codecentric.de> wrote:
Thanks, good hint.
For those inclined to understand my request, attached is the output of -XX:+TraceClassLoading

Using the xml binding feature approximately loads 800 classes (which represent about 5MB memory)

I haven't checked alternatives to the jaxb. And I am aware that this is a more esoteric requirement to reduce footprint.

However, I am sure if this would not be from the JDK, nobody would pull in a 5MB dependency to parse a single xml file.

Fabian


On Fri, Jul 22, 2016 at 9:25 AM, Guillaume Nodet <gnodet@apache.org> wrote:
Note that on older branches, the feature repositories are still parsed
using DOM
https://github.com/apache/karaf/blob/karaf-2.x/features/core/src/main/java/org/apache/karaf/features/internal/RepositoryImpl.java

The xml is now also written, that may be the reason why we switched.

2016-07-14 23:11 GMT+02:00 Fabian Lange <fabian.lange@codecentric.de>:

> Hi,
>
> i am looking into ways to trim down Karaf. I notices that Karaf uses JaxB
> to parse features.xml - However this is the only application of JaxB.
>
> Could somebody more involved help me to figure out if it is worth to
> replace it with manual marshalling? I assume other xmls are parsed
> differently?
> Advantage would be that the whole jaxb infrastructure could be avoided,
> including the contexts.
>
> I know manual parsing is a pain, but anyway, just wanted to throw this out,
> maybe somebody has a good suggestion.
>
> Fabian
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Guillaume Nodet
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