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Re: [xmlblaster] What happens to pubed msgs when history que is full?

Hallo Marshall,
You are right, the "discardOldest" is not implemented as a general feature of the queues. The history queue however acts as a FIFO queue (this functionnality is implemented in the core not in the queue itself). When this queue is full, the oldest entry is always removed to make space available, no matter if the queue depth is 1 or more.

This is a welltested feature so I guess you can sleep well again ;)


Marshall Shapiro wrote:
We are developing an application using xmlBlaster and a important issue came up.

I am confused about what happens to messages that are published to topics when the topic history queue is full.

In the engine.message requirement doc I found the statement "Further published messages with the same oid overwrite the previous message (the history depth is one)".

But someplace else in the documentation I found a that the default setting of the PublishQos attribute OnOverflow is "deadMessage", and that the attribute setting "discardOldest" may not yet implemented.

I don't know how to reconcile these. Please clarify (for both queue length equal 1 and queue length greater than 1).

This becomes an important issue for me in that my app requires that the latest publication to a topic always be in the queue, overwriting the older ones.



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