Features Induced by the Adoption of New Standards

Transcription

1 ISIS-SOL SOL mock-up : Key Features Induced by the Adoption of New Standards ierre Bornuat (S ommunications & Systems) March 1st, 2011 Authors : ierre Bornuat, ierre-alban ros, hristophe hi h ipo, S ommunications i & Systems; Marie-Laure Anadon, aul Gelie, NES

2 Introduction & ontext resentation NES plans to develop a new control centre, which should satisfy several main objectives Be compliant with international space standards (such as SDS: Mission Operations, Space acket rotocol, SLE -or ESS: US, etc.) Reduce possession costs and secure development of NES projects Define an evolutive and re-usable platform product line for control centers erform a first implementation to be operational in 2016 As a preparation of future developments, NES has delegated to S ommunications & Systems the development of a mock-up (ISIS-SOL) Evaluate service-oriented architecture (SOA), based on the SDS MO standard Evaluate possible technologies, check real-time performances on critical subsystems This presentation gives an introduction to the main characteristics of this mock-up, in terms of orientation (MO standard) Module orientation (OSGi technology) 2 S ommunication & Systèmes harte 2010

3 ISIS-SOL mock-up Oriented Architecture SDS MO standard main concepts Oriented Architecture: definition of architectural layers, use of modular components, communication through service interfaces Framework of standard services: components assembled as «plug-ins» Application Layer s onsumer / rovider MO Framework MO s Layer Message Abstraction Layer Missions Operations s Layer Message Abstraction Layer (MAL) ORE s (arameter, Action, ) ommon s (Directory, Login, onfiguration, ) OM (ommon Object Model) Generic Interaction atterns Access ontrol Quality of (QoS) Transport Layer Messaging Technology Framework to define new services based on the ommon Object Model (OM) 3 S ommunication & Systèmes harte 2010

4 ISIS-SOL mock-up Oriented Architecture MO services implemented in the mock-up ORE s arameter : manage arameter status information ISIS-SOL mock-up specificity: receive / distribute raw TM packets Action : invoke actions (i.e. remote commands) Aggregation : group several arameters in a single request Not used: Alert (raise and receive alerts), heck (check arameters against monitoring rules), Statistic (statistical evaluation of parameters), onversion (engineering unit conversion), Argument (access to Actions / Alerts arguments definitions) ommon s Directory : providers publish services / consumers discover available services Retrieval : retrieve blocks of historical data Replay : replay session (used in case of investigations) Not used: Login (authentication), onfiguration (configuration delegation to a service), Interaction (request input from operator) 4 S ommunication & Systèmes harte 2010

5 ISIS-SOL mock-up Oriented Architecture ISIS-SOL mock-up Architecture US Raw TM file List of T to be sent T sending client T logs ommand & ontrol Subsystem Demultiplexing Large Data Transfer ommanding arameter MAL (Message Abstraction Layer) (US 13 TM packets) (US <> 13 TM packets) Aggregation Retrieval (FD data) arameter (Recomposed Raw TM packets) (TM params) Replay (TM replay) Action (Emitted T) Flight Dynamics Subsystem Datastore Subsystem Local client Visualization Subsystem rovider onsumer 5 S ommunication & Systèmes harte 2010 MAL Messages Disk reads/writes

6 ISIS-SOL mock-up Oriented Architecture Focus on ommand ontrol Scalability and telemetry processing Modularity of telemetry acquisition chain results in a very adaptable system hanging On-Board telemetry format may impact a limited number of components: Demultiplexing and removal of service provider for Large Data Transfer Specific rocessing Adding a new specific processing for a type of telemetry packet can be achieved by adding a new which is a consumer of a arameter amete provided by Demultiplexing Demultiplexing Demultiplexing (TM Format X) Large Data Transfer Using specific packet processing for each type of packets (or group of type) can be done by only changing system configuration and launching as many daemons as necessary (for example, one per packet provider) 6 S ommunication & Systèmes harte 2010

7 ISIS-SOL mock-up Oriented Architecture Focus on ommand ontrol - ommands ommand Action is also encoded in compliance with ESS US standard Actions states: published by the ommand ontrol subsystem, archived by the Datastore subsystem Allows to follow action uploading in real-time or to replay sending command stacks Examples of possible adaptations to specific behaviors with a low impact on existing components, due to ISIS-SOL mock-up service oriented architecture: US Large ommands handled by a specific component which splits them into smaller actions, and requests ommanding to take them into account t(transparent tto the user) List of T to be sent T sending client 5 1 ommanding 2 3 Handling telemetry reports for actions processing: this could be achieved by simply modifying the ommanding and register it as consumer of a Aggregation rovider MAL (Message Abstraction Layer) 4 7 S ommunication & Systèmes harte 2010

8 ISIS-SOL mock-up Oriented Architecture MAL Joram - Quality of (QoS) One of the main benefits of using a MOM system for all exchanges in the system is that it provides several possible levels of Quality of (as required by SDS MO standard) BEST EFFORT Messages are not persistent Sending order is FIFO Fault tolerant to network errors: message re-emitted until sending is successful ASSURED Messages are persistent: a consumer will receive messages later if not present when the message was emitted Fault tolerant to both network and MAL (Joram) server errors. ossibly some messages loss if an error occurs on client reception QUEUED Same as ASSURED but all messages are acknowledged on the client-side Ensures that client has received a message TIMELY Not supported by Joram transport layer 8 S ommunication & Systèmes harte 2010

9 ISIS-SOL mock-up Module Oriented Architecture OSGi concepts and used technologies ommanding 9 OSGi: Java-based services framework, providing AIs and services Applications / components, organized as «bundles» (i.e. plug-ins) ISIS-SOL mock-up ommanding omponent ommand ontrol OSGi Bundles ommon OSGi Bundles S ommunication & Systèmes harte 2010 Application Manager OSGi ontainer JAVA JVM Agent ommanding OSGi ommon OSGi Operating Systems : MS Windows RedHat EL Equinox OSGi implementation Expected benefit: reduce complexity in most aspects of development ISIS-SOL mock-up ommanding = ISIS-SOL mock-up = OSGi application 2 Agent = OSGi application responsible for installations / updates ommanding composed of ommand control OSGi bundles ommon OSGi bundles ommanding uses Declarative Extension oint OSGi ontainer / JVM / OS

10 ISIS-SOL mock-up Module Oriented Architecture OSGi bundles as major software structure elements ommanding Application Entry point To ommanding omponent Standard Telecommand Upload rovides T log report (in the ISIS-SOL mock-up) Handles Telecommand Upload and Action Invocation service rovides an abstraction to MAL layer and SDS MO ORE layer Telecommand profile Encoding ommand ontrol OSGi Bundles ommanding OSGi ommanding Encoding OSGi ommanding Filtering Default OSGi ommanding Filtering OSGi Filter management for Telecommand Uploading ommanding Action OSGi ommanding Filtering Large Data Transfer OSGi ommand ontrol ommon OSGi Bundles ommon Action OSGi ommon OSGi Bundles ommon Action Engine OSGi Implementation Of ommon Action Engine Delegation of Telecommand management to LargeDataTransfer (large Telecommands) Lower level services to upload telecommands MOHelper OSGi MAL OSGi Log OSGi Log Management Exposed MO s initialization Access to MAL ommunication Layer 10 S ommunication & Systèmes harte 2010

11 ISIS-SOL mock-up Module Oriented Architecture OSGi bundles as major software structure elements Eclipse features ISIS-SOL mock-up uses Eclipse notion of features Feature = group of bundles, which defines the deployment strategy using 2 Repository mechanisms Separates logical software unit Guarantees that a group of bundles are coherent (software dependencies, prerequisite specifications) <feature> Demultiplexing Feature <feature> ommon Feature <OSGi bundle> ommon Action <OSGi bundle> ommon Action Engine <feature> ommanding Feature <OSGi bundle> ommanding filtering <OSGi bundle> ommanding Filtering LDT <OSGi bundle> ommanding Action <OSGi bundle> ommanding encoding <OSGi bundle> ommanding Filtering Default <OSGi bundle> ommanding 11 S ommunication & Systèmes harte 2010 <feature> Feature <feature> Large Data Transfer Feature

12 ISIS-SOL mock-up Module Oriented Architecture Deployment characteristics and Eclipse Equinox 2 repository Deployment based on 2 Repository (Web server HTT rotocol) All features are uploaded on this repository by an administrator After installation, ti every data exchanges go through the MAL (JORAM) Directory 5 4 Get DS URI 3 onnect to DS servlet JORAM (MAL) MAL tcp/ip 2 - Installer on workstation HTT tcp/ip 1 2 Repository 12 High level of modularity 2 repository allows easy upgrades on several machines, independently Every component can be installed on any server Scalability can be implemented easily (JORAM on a dedicated server for example) S ommunication & Systèmes harte Request / ublish service Action lient Demultiplexing ommanding Large Data Transfer 1 - Get installer from 2 repository ISIS-SOL mock-up ontainer

13 onclusions and first lessons learnt Although ISIS-SOL mock-up project is not finalized yet, some first lessons might be drawn from this mock-up. Integration of SDS MO standard and US standard : works pretty well! Our understanding and implementation of SDS MO s corresponds precisely to how we imagined it worked! ISIS-SOL mock-up Architecture (owing to SOA) enforces inter-operability and saves cost and time during software integration. Notion of bundles and use of OSGi technology : interesting to implement and to guarantee modularity of software components. Only negative point : DE Build (Eclipse build tool) is not very efficient to use when building large projects. Starting from a service-oriented description of the main control center functionalities, we have designed an architecture fully compliant with initial requirements. 13 S ommunication & Systèmes harte 2010

14 ISIS-SOL SOL mock-up : Key Features Induced by the Adoption of New Standards Annexes 1 - Documents and other references 2 - MO services : focus on the ommand ontrol subsystem (external & internal interfaces) 14 S ommunication & Systèmes harte 2010

15 Annex Documents and other references SDS standards SDS : Mission Operations Message Abstraction Layer SDS : Spacecraft Monitor and ontrol - ommon s SDS : Spacecraft Monitor and ontrol - ore s SDS 133.0B1 : Space acket rotocol SDS G-3 : ross-support concept part I - Space Link Extension s ESS standards d ESS-E-70-41A : and Telecommand acket Utilization ESS-E-ST : Monitoring and ontrol Data Definition OSGi standards Web Site : OSGi latform Release 4 15 S ommunication & Systèmes harte 2010

16 Annex ISIS-SOL mock-up Oriented Architecture MO services : focus on the ommand ontrol subsystem (external interfaces) <xml> TM/T Descriptions <xml> System configurations Install Admin Retrieve and Install applications arameter 2Repository TM arameters Instance Grouped TM arameters Directory Directory Actions Log Report ommand ontrol Subsystem Aggregation Action Datastore Subsystem US TM ackets Archives Executes action plan Action lient <xml> Action lan User ommon ORE roduces 16 rovider onsumer Uses S ommunication & Systèmes harte 2010

17 US TM ackets Annex ISIS-SOL mock-up Oriented Architecture MO services : focus on the ommand ontrol subsystem (internal interfaces) A1 0B Directory Demultiplexing Archives <read> Directory arameter US <> 13 TM ackets Aggregation A1 0B <use> <xml> TM/T Descriptions US 13 TM ackets A1 0B arameter A2 0 arameter Large acket A1 0B A2 0 <use> <write> Actions Log Report Directory Large Data Transfer Action ommanding Directory Action Action ommon ORE roduces 17 rovider onsumer Uses S ommunication & Systèmes harte 2010