Re: Configuration

[Alexey Parshin <alexeyp@gmail.com>]

It's possible to reload configuration. Especially if it's stored and
used like a hash array. BTW, SPTK has also a simple Windows INI-style
config support. It's also reloadable.

On 4/23/05, Thibaut Colar <tcolar@qarbon.com> wrote:
> On the company website, at some point i got sick of the web.xml changing
> all the time and restarting the webapp, and i had made a small app that
> was some html pages, where you can see all the servelts, there mappings,
> the number of time they got requested and the number of time there was
> an error. also there was a save button to save the config to disk, so it
> was reloaded later.
> So you could edit that, and reload the servlet on the fly, and it worked
> good, of course this was all in java and not very well done :-) , so it'
> no use to you, but i found it very practical for testing/debuggin/easy
> changes and no need to reload the whole webapp, so maybe whatever format
> you pick, you could have a cool tool like this ?
> 
> Though i have no idea if "reloading" a C++ servlet is actually doable :-)
> 
> Alexey Parshin wrote:
> 
> >It's included into SPTK and it doesn't use external XML libraries..
> >
> >On 4/23/05, Thibaut Colar <tcolar@qarbon.com> wrote:
> >
> >
> >>Well depends of the setup.
> >>For example sometimes i use tomcat standalone (not with apache +
> >>mod_jk), so if you want to define an error page you add this to xml:
> >><error-page>
> >>    <error-code>404</error-code>
> >>    <location>/404.html</location>
> >> </error-page>
> >>Also you can define error 5xx (servlet errors) that apache would not
> >>handle anyway.
> >>
> >>Also most of the time if you do use apache with pass through to tomcat,
> >>you would tell apache that everything in a context (ie: /servelts/) is
> >>to be handled (passed to) tomcat, so if something is missing in there
> >>apache won't handle the 404 since it delegated all to tomcat.
> >>
> >>other things i use myself:
> >>  <display-name>Viewlet Central</display-name>
> >>  <description>
> >>        Viewlet Central
> >>    </description>
> >>  <session-config>
> >>    <session-timeout>600</session-timeout>
> >>  </session-config>
> >>
> >>Other than that the rest i don't use much.
> >>
> >>Per servlets option i don't use but it's definitely something i think
> >>could be useful.
> >>
> >>As for XML, i agree with you and that is what i don't like with XML, a
> >>huge, very slow, memory hungry parser to read 5 key values :-)   but if
> >>you start to add parameters, etc ... to each servlets definition then it
> >>might be best ...
> >>
> >>Doesn't C++ have some light weight XML parser ? you really don't need a
> >>full blown one, just something to read attributes/values.
> >>
> >>Ilya A. Volynets-Evenbakh wrote:
> >>
> >>
> >>
> >>>Nah.. CPPSERV doesn't claim to support "standards", it claims to have
> >>>API losely based on that of J2EE Servlet API ;-)
> >>>This means we can (and probably will) invent config format of our own.
> >>>In fact XML parser is the last thing I want to
> >>>hook up to this engine - it will automatically add dependancy on libs
> >>>that are at least ~1.5 M in size. Not something I
> >>>want to have in embedded device.
> >>>
> >>>BTW, what do you mean by defining error pages? Isn't that done by
> >>>Apache? (ErrorDocument in .htaccess or apache.conf)
> >>>
> >>>So, config-wise - we have session timeouts, "application definitions" -
> >>>i.e. set of related servlets sharing ServletContext and
> >>>session name. I guess adding per-servlet parameters should be reasonable
> >>>(think multiple instances of same servlet
> >>>hooked to different databases, etc).
> >>>
> >>>Anything else?
> >>>
> >>>Thibaut Colar wrote:
> >>>
> >>>
> >>>
> >>>
> >>>
> >>>>Besides servlets definitions ?
> >>>>not: much, most common i define is error pages (404)
> >>>>and also very useful is session timeout.
> >>>>Have rarely used anything else, i f any.
> >>>>
> >>>>I'm not a big fan of the web.xml myself.
> >>>>1) it's xml ... so you know :-)
> >>>>2) it needs both the definitions, and then the mapping, and on most
> >>>>java containers it needs all the definitions first, followed by all
> >>>>the mappings, so it's annoying to edit (2 places).  But i guess it's
> >>>>an implementation issue so you don't have to make yours stupid like
> >>>>this :-)
> >>>>
> >>>>But, i guess you gotta make the web.xml regardless cause it's "standard"
> >>>>
> >>>>Ilya A. Volynets-Evenbakh wrote:
> >>>>
> >>>>
> >>>>
> >>>>
> >>>>
> >>>>>I'm thinking about configuration of servlets right now.
> >>>>>Ideas on what exactly should be configurable?
> >>>>>Should I perhaps use web.xml config format?
> >>>>>Question to those who program a lot of servlets:
> >>>>>What things have you ever actually configured in real life?
> >>>>>
> >>>>>All ideas are welcome.
> >>>>>
> >>>>>
> >>>>>
> >>>>>
> >>>>>
> >>>>>
> >>>>>
> >>>
> >>>
> >>>
> >>>
> >>
> >>
> >
> >
> >
> >
> 
> 


-- 
Alexey Parshin,

Senior DBA,
Tactical Telesolutions,
San Francisco