.. _restartmid:

===============
Restart
===============

    1. SDP Leaf Node provides API for **Restart workflow**.
    2. The SDP Leaf Node **accepts the command** if :-

        A. Operational **state** of the SDP Leaf node is **ON/OFF/INIT/STANDBY/ALARM**

    3. The SDP Leaf Node **rejects the command** if :-

        A. Operational **state** of SDP Leaf node is **FAULT/UNKNOWN** .

    4. The following **state requirements** are applied for the **command execution** :-

        A. SDP Subarray is in any of the 'observation state' - **FAULT,ABORTED,RESOURCING,CONFIGURING,IDLE,READY,SCANNING**
        B. SDP Subarray node is :term:`available` .

    5. The **command execution** involves below **key operations** :-

        A. Check for SDP Subarray obsState is done.

            - If it is in any of the **RESOURCING/IDLE/CONFIGURING/SCANNING/READY** obsState :-

                i. **Abort** command is sent to SDP Subarray.
                ii. Once Abort command **transitions** SDP Subarray to **ABORTED** obsState , **Restart** command is **sent** to SDP Subarray.

            - If it is **FAULT/ABORTED** , **Restart** command is sent to SDP Subarray.

        A. When **Restart** is invoked on the SDP Subarray.

            - If SDP Subarray **reports rejection/failure**, command failure is reported as **'RESULT_CODE - FAILED'** on Long Running Command Result attribute of the SDP leaf node.
            - If SDP Subarray **accept command** , the TMC SDP leaf node will wait for command completion.

    6. The SDP leaf node **monitors the progress** of command via the SDP sub-array node **ObsState transitions** and the **long running command results**.

        A. Command is **successful** when the SDP Subarray Node transitions to **EMPTY** ObsState. This is reported as **'RESULT_CODE - OK'** on Long Running Command Result attribute of the Subarray node.
        B. Command **failure** is reported in any of the below cases as **'RESULT_CODE - FAILED'** on Long Running Command Result attribute of the TMC SDP Subarray leaf node.

            - The SDP Subarray reports **error event** when command is invoked .
            - The command **times out** if SDP SubarrayNode **does not transition** to **EMPTY** within the **timeout period** specified by `CommandTimeOutDefault` property specified in helm chart of the SDP Leaf Node .