[xmlblaster-devel] Unifying property names

[Marcel Ruff <mr at marcelruff.info>]

Hi,

Michele and i where just discussing to unify the properties naming
convention of xmlBlaster:

o command line properties
o xmlBlaster.properties
  http://www.xmlblaster.org/xmlBlaster/doc/requirements/util.property.html

o xml QoS markup, see e.g.
  
http://www.xmlblaster.org/xmlBlaster/doc/api/org/xmlBlaster/util/qos/ConnectQosSaxFactory.html

o code naming of properties, see e.g.
  
http://www.xmlblaster.org/xmlBlaster/doc/api/org/xmlBlaster/util/queue/I_Queue.html

o administrative markup of porperties
  http://www.xmlblaster.org/xmlBlaster/doc/requirements/admin.commands.html
  (which covers SNMP, telnet, command-messages and JMX)


* Currently it is a mess as you can see in the examples below:

 -cb.queue.maxMsg 1000                       (command line)

 cb.queue.maxMsg=1000                        (xmlBlaster.properties)

 <queue relating='session' maxMsg='1000'/>   (ConnectQos markup)

 long getMaxNumOfEntries();                  (code example)

 /node/heron/client/joe/cbQueueNumMsgs=1000  (administrative command, 
telnet, SNMP etc.)


We believe the administrative approach is most universal and simple
(please see the XML structure in 
http://www.xmlblaster.org/xmlBlaster/doc/requirements/admin.commands.html)


* Here are some examples with the new approach:
  

 -queue/cb/maxEntries=1000          (relative addressed on client 
command line)
 -/node/heron/client/joe/queue/cb/maxEntries=1000    (command line, 
absolute addressed)

 queue/cb/maxEntries=1000           (xmlBlaster.properties, relative 
addressed)

 <queue>
   <cb>                             (the 'relating' from above - the 
callback queue)
     <maxEntries>1000</maxEntries>  (ConnectQos markup, relative to the 
invoking client)
   </cb>
 </queue>

 long getMaxEntries();              (code example)

 /node/heron/client/joe/queue/cb/maxEntries=1000   (administrative command)
 /node/frodo/topic/helloWorld/queue/history/maxEntries=10

                                    (add a CORBA plugin to heron)
 
/node/heron/ProtocolPlugin[IOR][1.0]=org.xmlBlaster.protocol.corba.CorbaDriver

 JdbcQueuePlugin/tablePrefix=xmlblast               (configure a 
specific plugin)
 /node/heron/JdbcQueuePlugin/tablePrefix=xmlblast
 /node/heron/client/joe/queue/cb/JdbcQueuePlugin/tablePrefix=xmlblast


* As you may have noted the markup consists of pairs like
 'node/heron'  where 'node' is the tag or class name and 'heron' is the 
instance ID
 'topic/helloWorld'  where 'topic' is the tag or class name and 
'helloWorld' is the instance ID

 Only for assignement the '=' signature is used ('/' would be possible 
as well)
 to visualize the purpose and to be URL compliant.


* Benefits:
 o Unified naming approach
 o Simple syntax
 o local (relative) settings are clusterwide expandable
 o XPath compliant syntax
 o URL compliant syntax
 o Automatic conversion from flat hierarchical view to XML view and 
vice versa
 o No [] brackets anymore which frightens Michele, Bjorn and even Cyrille
   (only for pugin type and version and for property arrays we still 
use [])


* Drawback for URL setting
 As described in the admin.commands requirement we have up to now
 used a '?' syntax when passing values, e.g.
  client/joe/-17/queue/cb/?maxEntries=30000
 to be URL comforming.
 This '?' will now be dropped for all configurations (like command line
 or telnet) and will be only used for browser write access.
 URL read access works fine without a '?'.


Comments are very welcome!

best regards

Marcel + Michele

PS: Thanks to Heinrich, Bjorn and Cyrille for their feedback