Double booking created by a broker guided service

I’ve one query in the broker service. We have two front end and two back end servers in our production and use load balancer to balance load between them. While creating a booking for a partner, first the front end server receives the EDIFACT doc and process it and sends it to back end server to insert the record in database. Most of the time this functionality works fine but sometimes [seldom] it creates two similar records in the database for a single booking request. It seems that sometime both the backend servers are processing the same insertion request and creating double booking. Can anyone tell me if this happens in broker service where two same service in two different back end server is connected to a single broker for load balancing purpose? Please let me know if u have any suggestions to get rid of this!

Can you be more specific about your configuration? “Front-end” and “back-end” are too generic to know what you mean.

If you have 2 IS instances connected to a single Broker queue, it is remotely possible that both instances may get the same document. This can occur when the document is delivered to one IS but before IS can acknowledge receipt it loses the connection. This causes the Broker to mark the document as undelivered and is thus a candidate to be delivered to the next requestor–which may be the other IS.

There are several approaches to detecting duplicates within IS. Review the wM-supplied docs for options.