Re: [xmlblaster] finding out from MsgUnit weather it is publish or subscribe message

[Michael Atighetchi <matighet at bbn.com>]

Marcel, Michele,

> Hi,
> 
> as we only need to support mirroring of requests and messages (and not 
> yet mirroring
> of session state informations) the changes to our cluster plugin 
> interfaces are probably
> not a big effort.
> The plugins need to return an array of suitable master nodes instead of 
> one (as is
> the current implementation).
> 
> This could be an approach for implementation:
> 
> - Only messages of stratum level 0 are mirrored.
> - All mirror nodes are masters (level 0) for their messages
> - In the current plugin setup the plugin can't control what happens on 
> error of
>  one cluster node. Ignoring the currently not available node and 
> deliver to all
>  others would be the behaviour. The client queue of the failing node would
>  tail back the message until the mirror is available again.
>  This needs probably some improvement to have more control in such a 
> situation.
> 

I yet have to dig through the Cluster code to look wheather this would
be sufficient for the protocol. In the meantime, I've looked into
implementing our protocol using the security plugins, and I think it should be
doable that way.

> Could you please sketch a detailed message flow of what you
> want to achieve (which cluster nodes and clients are involved in which 
> sequence)?
> 

Unfortunately, I cannot disclose the details of the protocol right
now. However, that situation will change come late August, when we can
give out information in an open-source manner. 

I realize that this is an awkward position (I would like you to
enhance xmlblaster but cannot tell you exactly for what), but have to
leave it at that.

> regards
> 
> Marcel
> 
> 

-- 
matighet at bbn.com   BBN Technologies