While a structure is in the Duplex Established phase, connectors will continue to receive notification through their event exits of new or existing connections and connection failures. Connectors receive event notification for both structure instances while both structures are allocated. Fields in IXLYEEPL identify the duplexed state of the structure.

New connectors to the old and new structures are allowed while in the Duplex Established phase. See Handling New Connections During a User-Managed Rebuild Process for a description of the actions a new connector must take when connecting to a duplexed structure.

The synchronization of duplexed structures is the responsibility of the connectors using them. In general, whatever can be done to a structure in simplex mode can be done to a structure in duplex mode. This includes altering the structures while they are in the Duplex Established phase. (See Altering a Duplexed Structure.)

The propagation of data to the new structure and the subsequent synchronization of that data through duplexing mainline operations to both structures is a matter of user protocol and solely the responsibility of the user. It is also the user's responsibility to handle failure scenarios, such as one of the duplexed structures reaching a “structure full” condition. MVS™ will handle failures such as loss of connectivity or failure of one of the structure instances, but the user should be prepared to handle other situations.