Re: [xmlblaster] persistance and graceful disconnect

[Marcel Ruff <mr at marcelruff.info>]

Martin Johnson wrote:
> Hi Marcel
>
> How would I achieve this use case.
>
> A client (socket) using a persistent connection and persistent 
> subscription disconnects from the server gracefully.
Hi Martin,

if you call on client side:

xmlBlasterAccess.leaveServer(null) ; // instead of 
xmlBlasterAccess.disconnect(...)

the client side resources are freed but the server maintains the session 
and
queues the subscribed messages.

The client should use a positive public session id like:

 "client/joe/session/1"

and can reconnect to this session on restart (to access the filled 
callback queue).
Further it should tell the xmlBlaster server on lost callback ping to 
retry, this is a command line example:

 java javaclients.HelloWorldSubscribe -session.name joe/5 -oid Hello 
-dispatch/callback/retries -1 -persistentSubscribe true

You should set -persistentSubscribe to true as well. In this case even 
the xmlBlaster server
may go down and on restart immediately collects messages for the 
subscriber (even if the subscriber
arrives a day later).
Like this no messages are ever lost.

What you describe is a very common use case used
most time with xmlBlaster and works very reliable,

regards
Marcel
> During this periond when the client is not available (ie shutdown for 
> some maintenance) the server continues maintaining session and 
> subscription queue. The client is then started again and connects to 
> same sessionid and recv's messages published during period of downtime.
>
> I have been trying with
>
>   <qos>
>     <deleteSubjectQueue>false</deleteSubjectQueue>
>     <clearSessions>false</clearSessions>
>   </qos>
>
> When calling disconnect()
>
>
> Without much luck.
>
> Regards
>
> Martin
>   


--
Marcel Ruff
http://www.xmlBlaster.org