karaf-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Jean-Baptiste Onofre ...@nanthrax.net>
Subject Re: [PROPOSAL] Disable autoRefresh on features service by default and simple optional features service
Date Fri, 08 Jan 2021 07:37:56 GMT
Hi,

I guess you didn’t read fully my message ;)

My proposal is:

- introduce the property and keep "true" (as it is today) on Karaf 4.2.x
- introduce the property and set to "false" (change) on Karaf 4.3.x.

Regards
JB

> Le 8 janv. 2021 à 08:16, Daniel Las <daniel.las@empirica.io> a écrit :
> 
> Hi,
> 
> It looks like some kind of backward incompatible change introduced within patch version
change. I personally would like to keep auto refresh "on" by default as this is expected/desired
behavior for me.
> 
> Regards
> 
> pt., 8 sty 2021 o 07:31 Jean-Baptiste Onofre <jb@nanthrax.net <mailto:jb@nanthrax.net>>
napisał(a):
> Hi everyone,
> 
> We got several user feedback, complaining about unexpected and cascaded (unrelated) refresh
while installing features.
> 
> As reminder, a refresh can happen when:
> - bundle A imports package foo:1 and a bundle provides newer foo package version. In
that case, the features service will refresh A to use the newest package version.
> - bundle A has an optional import to package foo and a bundle provides this package.
In that case, the features service will refresh A to actually use the import as it’s a "resolved"
optional.
> - bundle A is wired to bundle B (from a package perspective or requirement) and B is
refreshed. In that case, the features service will refresh A as B is itself refreshed (for
the previous reasons for instance). This can cause "cascading" refresh.
> 
> A refresh means that a bundle can be restarted (if the bundle contains an activator or
similar (DS component, blueprint bundle)).
> 
> In this PR https://github.com/apache/karaf/pull/1287 <https://github.com/apache/karaf/pull/1287>,
I propose to introduce a new property autoRefresh in etc/org.apache.karaf.features.cfg to
disable the auto refresh by the features service (and let the user decides when he wants to
trigger refresh with bundle:refresh command for instance).
> I propose to keep autoRefresh=true on 4.2.x and turn autoRefresh=false on 4.3.x.
> 
> Thoughts ?
> 
> On the other hand (and to prepare the "path" to Karaf5), I have created a new "simple
features service" (PR will be open soon) that:
> 
> - just take the features definition in order (ignoring start level)
> - ignore requirement/capability (no resolver)
> - no auto refresh
> 
> Basically, if you have the following feature definition:
> 
> <feature name="foo" version="1.0">
>   <feature>bar</feature>
>  <bundle>A</bundle>
>  <bundle>B</bundle>
> </feature>
> 
> The features service will fully install/start bar feature first, then bundle A, then
bundle B.
> To use this "simple features services, you just have to replace org.apache.karaf.features.core
by org.apache.karaf.features.simple bundle in etc/startup.properties (or custom distribution).
> 
> It’s similar to the Karaf 5 extension behavior (I will share complete details about
Karaf 5 and its concepts (module, extension, …) very soon, but that’s another thread ;)).
> 
> The big advantages of this approach is:
> - predictable/deterministic provisioning (if it works fine, it works again)
> - faster deployment (I estimated the gain to about 70%)
> 
> Thoughts ?
> 
> If you agree, I will move forward on both tasks.
> 
> Thanks,
> Regards
> JB
> 
> 
> -- 
> Daniel Łaś
> CTO at Empirica S.A.
> +48 695 616181


Mime
  • Unnamed multipart/alternative (inline, None, 0 bytes)
View raw message