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Re: [xmlblaster] When does a topic get marked dead?

hallo David,

As I see it you have several possibilities to solve your problem:
first of all you should consider structuring your system in such a way to get a limited amount of topics. Topic creation is timeconsuming and should be kept to a minimum.

An alternative to the described approach would be to limit the lifetime of the topics by reducing the destroyDelay of the topic or the lifetime of the message. Read more about it in the following requirement:


If you are using a PtP pattern or a PubSub where all subscribers are connected before any publishing then you could also consider using the volatile flag in the publish qos.

As you see you have several options. Personally I would focus in trying to limit the amount of topics.

Saluti Michele

David Kerry wrote:

We used to run xmlblaster v0.8 for quite some time, but have now
moved to v0.9.

Everything is running fine, but we have a problem where xmlblaster
keeps running out of memory.

We're using ram based storage for now (which we also used in the
v0.8 version).  This shouldn't be a problem as our traffic is
fairly low and all messages are volatile.

The problem seems to be that a new topic gets created for every
message (when we publish we give a blank oid and let the server
fill it in).  The server then gets all plugged up with hundreds
or thousands of topics with no messages in them.

We also see this behaviour when we use a database (Oracle) and
use it for all the topic/message storage.  The database tables
just keep getting bigger and bigger and never seem to shrink.
This causes a problem when we restart xmlblaster too because it goes
and loads in all the old entries from the database which can take
a long time (10-15 minutes).

So I guess the question is - how can I force xmlblaster to check
for dead topics more often and clean them out?

Michele Laghi
mailto:laghi at swissinfo.org
tel. +46 8 7492952 / mob. +46 70 4103964