Camel Aggregator retains the old exchange in case of exception

Hi,

I have a custom aggregation strategy from which another camel route is
called using a producer template.
When an exception occurs in the sub route, the aggregator's old exchange
does not get cleared as the aggregation completion size is not complete as
per the route definition.
When i restart the whole process , the last failed exchange remains in the
oldExchange of the aggregator rather than becoming null.

I know that there is an aggregation repository that stores all the
exchanges, but in this case i want the aggregator to know that there has
been an exception and when it gets invoked for the next time, it should
start from scratch rather than picking up the failed exchange.