Secondary-to-primary flow matrix

The following table illustrates the actions taken when resynchronizing a session and the STSN command flows from the secondary half session to the primary half session.

The first result in each table cell represents the STSN command action; the second result represents the response returned to the STSN command. These are separated by a slash (/). When two STSNs are sent, they are separated by a comma.

Table 1. STSN secondary-to-primary flow
Primary Secondary, session cold Secondary, pending Secondary, decision to commit Secondary, decision to back out Secondary, invalid Secondary, not pending
Not received: pending  1  Set and Test / Reset

 2 
Set and Test/
Positive

 3 
Set and Test/
Negative

 4 
Set and Test/
Positive

  5  Set and Test / Invalid  6  Set and Test / Positive
Received: pending  7  Set and Test / Reset

 8 
Set and Test/
Positive

 9 
Set and Test/
Positive

 10 
Set and Test/
Negative

  11  Set and Test / Invalid Not Applicable

Notes to the preceding table

 1 
The STSN sender is not COLD. The STSN receiver has no sequence numbers. The session continues.
 2 
The STSN receiver has a pending work unit and has held onto locks and not committed resources. The sequence number sent on the SET AND TEST action code indicates that the STSN sender did not receive the pending RQ*2. Therefore, the STSN receiver backs out the pending work unit to the last commit point and returns a TEST POSITIVE on the STSN response.
 3 
The STSN receiver had a work unit pending and decides to commit resources and release locks. The STSN sender did not receive the RQ*2 sent by the STSN receiver. The STSN receiver returns a TEST NEGATIVE on the STSN response to inform the STSN sender that a wrong decision was made. The STSN sender can continue the session by sending SDT or decline by sending UNBIND.
 4 
The STSN receiver had a work unit pending and decides to back out the pending work unit. The STSN sender never received the pending work unit, and the STSN receiver returns a TEST POSITIVE on the STSN response.
 5 
The STSN receiver detects a severe loss of synchronization (possible log data set mismatch) and returns an INVALID on the STSN response.
 6 
The STSN receiver has no pending work unit and agrees with the sequence numbers sent on the STSN; therefore, it replies with a TEST POSITIVE.
 7 
The STSN sender is not COLD. The STSN receiver has no sequence numbers. The session continues.
 8 
The STSN receiver has a pending work unit and still holds resource locks. The number sent by the STSN sender on the S-P SET AND TEST indicate to the STSN receiver that the STSN sender received the pending work unit. The STSN receiver commits the pending work unit and responds TEST POSITIVE.
 9 
The STSN receiver had a pending work unit and decides to commit the pending work unit. The number sent by the STSN sender on the S-P flow indicates that the STSN sender received the RQ*2 and a TEST POSITIVE is sent on the STSN response.
 10 
The STSN receiver had a pending work unit. The receiver decides to back out that work unit and release the locks. The number sent by the STSN sender on the S-P flow indicates to the STSN receiver that the RQ*2 was received and processed by the STSN sender. The STSN receiver indicates the wrong decision by a TEST NEGATIVE on the STSN response. The STSN sender can continue the session by sending SDT or decline by sending UNBIND.
 11 
The STSN receiver detects a severe loss of synchronization (possible log data set mismatch) and indicates this to the STSN sender by an INVALID in the STSN response.