1. A method of selecting a holding storage device for messages received on a service bus, the method comprising: receiving a message at the service bus, the message having one or more properties; determining one or more storage selection rules based on the one or more properties of the message; determining a plurality of statuses for one or more candidate holding storage devices, each candidate holding storage device having a storage type and a status; determining a plurality of respective weight values for the one or more candidate holding storage devices, the determining based on respective weights for the one or more storage selection rules as adjusted by respective statuses in the plurality of statuses for the candidate holding storage devices; selecting a holding storage device from the one or more candidate holding storage devices based on the plurality of respective weight values; and storing the message in the selected holding storage device.