Patent attributes
In one aspect, automatic recovery of a synchronous replication session in response to an error is provided for a storage system that includes a source and target sites. During an active sync replication session in which a state machine indicates the system is operating in sync, an aspect includes monitoring input/output (IO) operations. Upon determining an occurrence of the error in which data has been persisted at the source site but not at the target site, an aspect includes discontinuing replication to the target site and transitioning the state machine from a sync state to a tripped state. Upon determining, during the tripped state, resources exist to conduct sync replication remote data transfer operations, transition the state machine to an async_to_sync state. The async_to_sync state causes the storage system to initiate a recovery operation to return the source and target sites to the sync state.