1. A computer system comprising: a queue assignment handler configured to associate a serialization context with a source queue used to transmit messages; and configured to receive a change in queue assignment of the serialization context from the source queue to a target queue; a queue monitor configured to monitor messages associated with the source queue and the target queue; and a queue scheduler configured to execute the change in queue assignment, including being configured to: determine, from the queue assignment handler, the change in queue assignment of the serialization context to the target queue; suspend transmission of existing messages from the source queue and the target queue, and disable a placement of subsequent messages into the source queue; schedule placement of the subsequent messages within the target queue; resume transmission of the existing messages from the source queue; and receive, from the queue monitor, notification of completion of the transmission of the existing messages from the source queue.