Re: [jetty-dev] latest NPN and start.jar

[Simone Bordet <sbordet@xxxxxxxxxxx>]

Hi,

On Fri, Sep 13, 2013 at 1:30 PM, Eirik Bjørsnøs <eirbjo@xxxxxxxxx> wrote:
> Another idea:
>
> If we rewrote NPN into a -javaagent, we could figure out at runtime which
> JVM we're running on and replace the necessary byte code on class loading
> time by looking it up in a catalog. That way we at least could decouple the
> runtime distribution of Jetty from exact JDK versions, allowing us to
> support older JVMs. And the catalog could be even be updated independently
> from the Jetty release. (Well, so can npn-boot today, so there's nothing new
> there really :-)

Sure, that's what I was discussing with Greg.

However, it raises the question of where you host this catalog.
Could be Maven Central, could be Eclipse, could be GitHub, but there
is a fundamental problem: the agent must have outbound connectivity to
the Internet to access it.
Many installations I worked with do not have that (to avoid crackers
to be able to download exploits).
Furthermore, those services may be down, and if they are what do we do ?

However, it could be a good alternative (there are many other
installations that do have access to the Internet), so I'll look into
it.

On a similar note, we're discussing to change the npn-boot jar name to
contain the JDK version, and interpolate ${java.version} in Jetty 9.1
to download the right jar for you the first time.
Not fool proof, but it's a start.

At the end, I see no easy solution.

My take was that if people is using SPDY, and they followed the
documentation, they know it requires NPN and that NPN depends on the
JDK.
So they know that if they change the JDK they run their webapps with,
they may have to update NPN too.
And these advanced users are smart and know to lookup the NPN versions
from http://www.eclipse.org/jetty/documentation/current/npn-chapter.html#npn-versions.

While I agree that a simpler mechanism would be better, I am not sure
one exists.

Keep throwing ideas, though.

-- 
Simone Bordet
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