This sounds good to me. I've one question, where do you configure the
path for the status servlet? At least the sling main servlet needs to
know this path. So why not making this an integral feature of the main
servlet?
Carsten
Bertrand Delacretaz wrote:
Hi,
We had a chat with Felix about a way to provide an URL that tells the
outside world whether a Sling application is ready to run, after
startup. I need this for an application that launches a Sling
application, and opens the browser on its welcome page once the
application is ready.
The "ready to run" condition can be tricky to evaluate, as there's a
lot of asynchronous stuff going on when starting a Sling application
(which might include creating and initializing a JCR repository).
The existing HttpTestBase.slingServerReady() method uses a simple
mechanism that is good enough for integration testing, but not
extensible and entirely defined on the client side.
To provide a customizable readyness test, we suggest the following:
1) Create a SlingStatusServlet mapped to /system/sling/status
2) SlingStatusServlet depends on the JcrResourceResolverFactory, and
returns an HTTP 503 status as long as that's not available. This is
the minimal test of Sling readyness.
3) SlingStatusServlet looks for scripts in the repository, under
/system/sling/status, which must only contain nodes that can be
adapted to scripts
4) All scripts found there (finding none is acceptable) are executed,
their output is concatenated in the servlet response, and if any of
them throws an exception the status servlet returns a 503 error.
5) Before processing requests, the SlingMainServlet asks the
SlingStatusServlet if it thinks the system is ready (based on the
above dependencies + scripts), and if not throws a 503 error,
indicating the reason.
Requests to /system/sling/status bypass this mechanism, of course.
Once the SlingStatusServlet returns true for this call, the
SlingMainServlet does not make the call anymore.
This should provide an easily extensible way of finding out whether
Sling applications are completely initialized.
WDYT?
-Bertrand
--
Carsten Ziegeler
[EMAIL PROTECTED]
