Re: [xmlblaster-devel] Getting Cluster Information ...

[Marcel Ruff <mr at marcelruff.info>]

Hmm,

if you look at the cluster configuration:

==============
cluster.node.id=heron.mycomp.com
==============
This defines the unique name of a cluster node.

(see http://www.xmlblaster.org/xmlBlaster/doc/requirements/cluster.html)

The following configuration could be easily a message content.
The few classes in org/xmlBlaster/engine/cluster do all cluster specific
processing.

<clusternode id='heron.mycomp.com'>
  <connect><qos>
     <address type='IOR'>
        IOR:09456087000
     </address>
     <address type='XMLRPC'>
        http://www.mycomp.com/XMLRPC/
     </address>
     <callback type='SOCKET'>
        socket://mycomp.com:7604
     </callback>
  </qos><connect>
  
  <master type='DomainToMaster' version='0.9'>
     <![CDATA[
        <key domain='RUGBY'/>
        <key type='XPATH'>//STOCK</key>
     ]]>
  </master>
  <master stratum='1' refId='frodo' type='MyOwnMapperPlugin' version='2.0'>
     <![CDATA[My own rule]]>
  </master>

  <state>
     <cpu id='0' idle='40'/>
     <cpu id='1' idle='44'/>
     <ram free='12000'/>
  </state>
</clusternode>


The NodeParser.java class parses this xml:
- NodeInfo.java parses the above <connect> address informations,
- NodeDomainInfo.java parses the <master> part
- NodeStateInfo.java parses the <state> part (is currently not used)

ClusterManager.java:221 starts parsing the above XML given from 
xmlBlaster.properties.
We could now as well send the XML with a message, say to topic

  <key oid='__sys__cluster.node[heron.mycomp.com]'>

and the ClusterManager could subscribe on topics starting
with '__sys__cluster.node' (or easier just intercept it in 
RequestBroker.java)
and reconfigure itself.
This needs to be looked at in more detail and there are certainly some
subtle issues popping up during coding but generally it should work.

If you gonna code it you are welcome to contribute
it to xmlBlaster,

regards
Marcel



Arghad Arnaout wrote:
> Hallo Marcel:
> you wrote
> " In fact it was/is planned that each cluster node information is a
> message so we
> can dynamically reconfigure cluster nodes, but this approach needs some
> lines of code to be added, "
>
> So would you please to explain that ??!!
> How we can implement that to configure the cluster node dynamically 
> ... ????
>
> Thank you ..
>
> ARGHAD
>
> On 4/17/06, *Marcel Ruff* <mr at marcelruff.info 
> <mailto:mr at marcelruff.info>> wrote:
>
>     Arghad Arnaout wrote:
>     > Hallo everybody:
>     >
>     > OK .. regarding to the business requirements, we need to know
>     and see
>     > the information of all xmlBlaster nodes in xmlBlaster Cluster,
>     > so my design to solve this issue in xmlBlaster Environment is
>     like the
>     > following:
>     >
>     > I designed such a plugin that runs at each node of the cluster and
>     > this plugin publishes the information about the current node under a
>     > specific topic, so what I need to do from the client side just
>     to get
>     > the messages under this topic (using get() or subscribe()).
>     >
>     > So .. is that the right way to implement such things ???
>     Yes, this way is OK.
>
>     In fact it was/is planned that each cluster node information is a
>     message so we
>     can dynamically reconfigure cluster nodes, but this approach needs
>     some
>     lines of code to be added,
>
>     regards
>     Marcel
>     > All the comments are welcomed...
>     >
>     > Thank you
>     > ARGHAD
>     >