Use Case: Scheduler: Interactive Mode Operations

Interactive Mode Operations Use Case for the ALMA Scheduler software based on ALMA SW Memo 11, Science Requirements and Use Cases, modified to include interactive mode scheduler events (e.g. when the scheduling software runs in manual mode).

Goal:   Provide scheduling functionality to the Operator to allow manual scheduling of ALMA SBs for observation. Once an SB is scheduled manually, automatic functions such as initiating SB execution, updating project status, and starting the Science Pipeline will execute for that SB.

Contact Authors:   M. Wright, D. Shepherd, A. Farris

Role(s)/Actor(s):
Primaries:

• Scheduling subsystem
  
• Executive subsystem - activates Scheduler.
  

• Operator, Staff Astronomer - monitors scheduler activities, examines master "look-ahead" schedule.
  
• Archive Subsystem - repository for verified SBs ready for scheduling, receives project status update from Scheduler.
  
• Telcal Subsystem - Provides results of on-line calibration to the Scheduler.
  
• Control subsystem - executes a scheduling block.
  
• Science Pipeline Subsystem - Initiated by Scheduler according to "Project Definition Structure."
  
• PI - the PI is informed of observing results for an SB by the Scheduler "Project Manager" software.
  

Priority:   Critical

Performance:   Must run in near-real time (within seconds).

Frequency of Use:   Once the Scheduler is started in Interactive Mode, it only begins SB processing when told which SB to process. Interactive Mode operations will be useful during commissioning, maintenance, and when a project requires time-critical, real-time inputs by the Operator or PI).

Preconditions:

1. Verified scheduling blocks (SBs) associated with a project have been placed in the Archive by the Observing Tool. A Project consists of "Obs Unit Sets" which link 1 or more SBs into a group (e.g. an Obs Unit Set defines SB ordering) and a "Project Definition Structure" which identifies, e.g., science priority, breakpoints, data processing requirements, project status, PI notification requests. The Scheduler must be able to read the Project Definition Structure and associate project constraints with each SB.
2. The Project Definition Structure must identify that the SBs available for consideration by the Scheduler require Interactive Mode operations.
3. SBs have a required initial setup.
4. SBs in the Archive will identify certain antennas for scheduled maintenance or moves. The Master Scheduler can handle the situation in which some subarrays are running automatically while others are in interactive mode.
   
5. Note: an Executive-supplied scheduling Policy is not required.
6. The Control subsystem is active and ready to execute an SB when commanded by the Scheduler. The Control subsystem also provides information needed by the Scheduler upon startup.
7. The Science Pipeline may be active and ready to process data from a completed SB when requested by the Scheduler. If it is not taking requests, then the Scheduler will queue its processing requests in the Archive and the Science Pipeline will process the queue when it is ready.
8. The Archive permissions are set to allow the Scheduler/Project Manager to write to the Archive and to link Science Pipeline results to the Project Definition Structure.
9. The Executive subsystem activates the Scheduler by issuing a startScheduling() command.

Basic Course:

1. Note: the PI, Operator, or Resident Astronomer will have a limited set of commands they can issue to make decisions (e.g., select/start a new SB, stop SB processing, retrieve new SBs from the Archive) along with the input decisions identified below.
2. The Master Scheduler creates a Subordinate Scheduler that operates in interactive mode. The command sequence specifies either the amount of time the Scheduler is to remain in Interactive Mode or that the Scheduler start with an indefinite time frame.
3. The Subordinate Scheduler waits for external input.
4. External input is received to run a specific SB.
5. If current weather or array conditions (collected by the Master Scheduler during nominal operations - See the Dynamic Mode Operations Use Case for details) suggest that the data taken will be compromised, then the Master Scheduler will issue a warning summarizing the problems. If all conditions are go, the Master Scheduler will issue an "All OK" type of statement.
6. SB execution and processing are the same as those specified in Dynamic Mode Operations.
7. 10 minutes before the end of Interactive Mode operations, the Master Scheduler issues a notification to the Observer that interactive operations will stop automatically in 10 minutes. This is necessary input so the Operator can wrap things up or tell the Executive subsystem that Interactive Mode ops should continue. If this mode is to continue, the Executive should send a notification to the Master Scheduler to extend Interactive Mode. More or less warning time defined? (10 minutes chosen somewhat arbitrarily).

Postconditions:

1. The Project Definition is updated in the Archive (includes completion status and link to data & Sci Pipeline results).
2. The system logs are available in the Archive. SB ranking results in a log file are not needed given that the SB choice was manually selected. However, a summary of how the current weather and array conditions will likely affect the data should be included in the logs.
3. The Subordinate Scheduler completes the basic course described above. It will send notification to the Observer of the status and will sit and wait for input.
4. The Master Scheduler will poll the Archive to look for break point responses from the PI and new SBs to process.

Issues to be Determined or Resolved:  

1. If the PI/Operator/Resident Astronomer terminates the session early, what happens to the balance of the time?

Notes:  

1. This Use Case was created by D. Shepherd based on conversations with Allen Farris and Mel Wright to help define the Scheduling test plan. Relevant SSR Use Cases from SSR Memo 11 are 4.3 (Schedule SB) & 4.4 (Execute SB)
   

   Last modified: 12aug03