Computing & Network Resources for Spacecraft Systems

1. Computing & Network Resources for Spacecraft Systems An Adaptive Resource Management Approach Ryan Detter, Barbara Pfarr - Goddard Space Flight Center Lonnie R. Welch, Brett Tjaden, Eui-Nam Huh - Ohio University

2. Agenda • Overview 3-6 • Adaptive Resource Management Approach 7-9 • Reconfigurable Computing Strategy for ITOS 10-13 • Modeling ITOS for DeSiDeRaTa 14-26 • Future Work 27 • Project Goals 28 2

3. Overview • Use adaptive resource management middleware, DeSiDeRaTa (Dynamic, Scalable, Dependable,Real-Time Systems), developed by Lonnie Welch, to convert an existing, non-distributed NASA/Goddard Satellite Command and Control System, ITOS, to a dynamically distributed system. 3

4. Overview cont. • Project Goals • Demonstrate feasibility for adaptive resource management in a ground-based command and control system • Collect metrics to measure system improvement • Provide a ground-based testbed for future distributed systems in space • Ultimately optimize resource use in real-time, distributed computing systems, whether in space or on the ground 4

5. Overview cont. • Project Significance • Demonstrates capability of Adaptive Resource Management, using metrics and real-time feedback, to optimize resource utilization for distributed real-time systems • Enables the system to have more compute power with fewer processors • Adapts real-time systems to dynamic workloads 5

6. Commercial Communication Network Optical Crosslink Optical Crosslink Ka Crosslink Active Optical Ka Ka Ka Passive Optical In-situ User PC Based GS Comm Gateway Digital Library Metadata Warehouse Earth Science Vision-Distributed Information-System-in-the-Sky • Interoperating Measurement Systems (Air / Spacecraft / In-situ) • Flexible Measurement Network Architecture • Direct Distribution of Derived Products • Network Computing- in-the-Sky

7. Adaptive Resource Management Approach • DeSiDeRaTa implements a dynamic path paradigm for modeling and resource management of large-gain, distributed real-time, mission-critical systems via middleware mechanisms for adapting resource allocations • Resources needed by applications are determined by experience, rather than by a priori estimates or worst-case execution times. • Performance of applications processes is judged using Quality of Service (QoS) metrics collected by DeSiDeRaTa Software Management System • Provides a Framework for reasoning about the real-time performance of distributed application systems 7

8. Adaptive Resource Management Approach cont. • Dynamic Path Concept of real-time systems • Path-level QoS specification for dynamic configuration at subsystem level • Dynamic paths consist of sensors, actuators, and control software for filtering, evaluating, and acting • May have timing constraints, have dynamic behavior, be scaleable, and be fault tolerant • Data/event source produces a stream of data/events, which cause a consumer to perform processing • Source is usually one or more sensors • Consumer is usually one or more actuators 8

9. Adaptive Resource Management Approach cont. Logical Architecture 9

10. Reconfigurable Computing Strategy for ITOS • Reasons Why DeSiDeRaTa can be beneficial to ITOS: • Workload is environment dependent and varies at run-time in several ways: • Telemetry data varies • Number and types of displays vary • Number of telemetry streams varies • Types of elements within a telemetry stream varies • Number of workstations being served with telemetry data varies 10

11. Reconfigurable Computing Strategy for ITOS cont. • Reasons Why DeSiDeRaTa can be beneficial to ITOS: • ITOS has the ability to handle varying workloads via utilization of a pool of distributed resources • ITOS and DeSiDeRaTa integration provides NASA with significant risk mitigation for the Earth Science Vision 11

12. Reconfigurable Computing Strategy for ITOS cont. • ITOS and DeSiDeRaTa integration steps • Model sensors, actuators, applications, and communication relationships • Construct a real-time paths model • Identify fault tolerance requirements • Specify above properties in D-Spec (DeSiDeRaTa’s spec language) 12

13. Reconfigurable Computing Strategy for ITOS cont. • ITOS and DeSiDeRaTa integration steps cont. • Obtain resource usage profiles for applications and paths • Make applications scaleable & fault tolerant • Determine effectiveness through extensive experimentation 13

14. ITOS Systems/Subsystems • Event System • Telemetry System • Command System • Spacecraft Test and Operations Language(STOL) System • Frame_sorter Subsystem • Display Subsystem 14

15. ITOS Systems/Subsystems cont. frame input archive cmd_transmit event_fifo vc_sorter fop dsp_event output pkt_extract cmd_load fop_mux dsp_evtdsp archive stolf_i/f stol tlm_client evt_forward stol_wkp stol_fifo dsp_evtlog ODB dsp_mnepage dsp_seqprt dsp_plot eqn_cfgmon Ext. Apps. dp_server Display File Network Availability 15

16. Event System • Logs every ITOS action performed • Generates logs in display window for operator’s use • Archives logs in files for future reference 16

17. Telemetry System • Used whenever data is received from spacecraft • Converts data frames into data packets and then into data sets • Installs the data sets into the ITOS database (ODB) 17

18. Command System • Creates the frames from the data packets • Sequences the frames • Sends command to spacecraft • Performs closed-loop command verification with CCSDS COP-1 protocol 18

19. STOL System • used to control the configuration and execution of all ITOS systems • Used to send commands to the spacecraft • Non-trivial operations are performed by multiple STOL commands (procedures) 19

20. Modeling ITOS • Identify conceptual framework of sensors, actuators, applications, and communication relationships in the real-time system • Define real-time paths, data and event streams, and path behavior 20

21. Sensors, actuators, applications and communication relationships sensors applications actuator 21

22. ITOS Sensors, Actuators, and Applications • Sensors • Telemetry: Spacecraft • Command: STOL • Event: ITOS components • Actuators • Telemetry: STOL, Displays, fop • Command: Spacecraft • Event: dsp_evtdsp, evt_forward, dsp_evtlog • Applications: All command, telemetry, and event components 22

23. Defining real-time paths, data & event streams 23

24. Defining Path Behavior Situation assess. (continuous) event Sensors Actuators Initiation (transient) monitor & guide (quasi-contin.) event 24

25. ITOS Model Path Behavior • Data generated after an event occurs. Once the event occurs, the flow is continuous. • Each mnemonic, event message, and command varies in size 25

26. ITOS Model Path Behaviorcont. • Data Flow: Quasi-Continuous • Path Activation: STOL event • Data Size: Dynamic 26

27. Future Work • Identify timing & fault tolerance requirements • Insert probes into ITOS • Represent model into D-Spec files • Obtain resource usage for ITOS applications & paths • Make applications scaleable & fault tolerant • Perform extensive experimentation to determine effectiveness of approach 27

28. Project Goals • DeSiDeRaTa middleware fully integrated into ITOS system • ITOS distributed at the sub system (path) level across multiple, heterogeneous platforms • Dynamic reallocation of resources based on changing environment and unforeseen occurrences 28