Re: [xmlblaster] History Queue Plugin Issue

[Marcel Ruff <mr at marcelruff.info>]

Hi Jonathan,

The specific topic configuration is done by a publish:

  
http://www.xmlblaster.org/xmlBlaster/doc/requirements/interface.publish.html

I think your RAM based topic came to existence with an initial RAM 
configuration
to this topic (oid) during first publish.

You can't change the history queue plugin implementation dynamically for 
an existing topic,
the only way is to delete and recreate the topic.
But it is possible to change the size of a history queue by an 
administrative
message (or in xmlBlaster.properties on startup).

This script shows some details, you can try it on command line:

============ adminPublish.xml START ===========
<!--
  This example sends an administrative message: a reconfiguration for 
the topic properties.

  java javaclients.script.XmlScript -requestFile adminPublish.xml
-->

<xmlBlaster>

 <connect/>

 <input message="Hit a key to pubish with RAM history queue # "/>
 <publish>
    <key oid="Hello"/>
    <content>Hi</content>
    <qos>
       <topic>
         <queue relating='history' type='RAM' version='1.0'/>
       </topic>
    </qos>
 </publish>

 <input message="Hit a key to publish administrative with CACHE history 
queue # "/>
 <publish>
    <key oid="Hello"><airport /></key>
    <qos>
       <priority>9</priority>
       <administrative/>
       <topic readonly='false' destroyDelay='-1' createDomEntry='true'>
         <queue relating='history' type='CACHE' version='1.0'
                maxEntriesCache='1009' maxEntries='1009' 
maxBytesCache='100000' maxBytes='100000'/>
       </topic>
    </qos>
 </publish>

 <disconnect />
</xmlBlaster>
============ adminPublish.xml END ===========

You can create a dump on the xmlBlaster server command line with

d /tmp/dump.xml

and see how the topic configuration changes, but NOT the queue 
implementation.

regards
Marcel

Clark, Jonathan wrote:
> Marcel,
>  
> I've run into a problem that I'm hoping you can help me on.  I've got 
> 2 different kinds of topics that are being published on a given 
> domain.  The first kind of topic is a heartbeat that is generated 
> every 15 seconds by a plugin.  The oid on all of the heartbeat 
> messages is the same.  The second kind of topic is generated by an 
> external
> client that generates messages based on outside input.  These topics 
> have different oids although there are often several updates for a 
> given oid.  The
> problem that I've run into is that the 2nd kind of topic is supposed 
> to be persistent, but the history queue is not getting written to the 
> database.  In researching
> the problem, I've found that the history queue is using the cache 
> plugin for the first kind of topic, but is using the ram plugin for 
> the second kind of topic
> which is why it doesn't get written to the database.  However, I don't 
> see anything in the configuration files that would indicate that these 
> kind of topics would
> use different plugins for the history queue.  Any thoughts on where to 
> look?
>  
> Thanks,
>  
> Jonathan Clark
> Open Roads Consulting, Inc.
> 757-546-3401
>  


--
Marcel Ruff
http://www.xmlBlaster.org
http://watchee.net
Phone: +49 7551 309371