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HLA und SOA

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HLA und SOA

  1. 1. HLA und SOA - Gemeinsamkeiten, Unterschiede und mögliche Schnittstellen 9. HLA Forum 2007 am 7. März 2007 Universität Magdeburg / Fraunhofer Institut IFF Prof. Dr.-Ing. Thomas Wiedemann, HTW Dresden wiedem@informatik.htw-dresden.de
  2. 2. Overview & Motivation • HLA is well situated in the simulation area, but not in other IT-domains • Service Oriented Architectures (SOA) are a new level in distributed infrastructures, but the application in simulation is not tested • This presentation – compares both technologies – shows equal and different characteristics – discusses possible interfaces or mixed architectures HLA und SOA - Wiedemann / HTW Dresden - Page 2
  3. 3. Common characteristics of HLA and SOA HLA & SOA are both Architectures (standards) and no products for realization of distributed software systems for both architectures exist different implementations HLA (different DMSO RTI ´s , Pitch, etc.) SOA (> 30 systems from Oracle, IBM, BEA, … ) HLA and SOA link software components & applications together the links are realized by data exchange between the components the data exchange is controlled and scheduled by special tools: HLA : Run-Time-Infrastructure (RTI) SOA : Enterprise-Service-Bus (ESB) both architectures use TCP/IP-based networks for data exchange (SOA can also use file-based data exchange or emails) HLA und SOA - Wiedemann / HTW Dresden - Page 3
  4. 4. Similar characteristics of HLA and SOA HLA & SOA the SOA - goal of “SERVICE ORCHESTRATION” could be accepted also as an HLA goal -> “Simulation tool orchestration” The orchestrated components can include a wide area of applications : HLA : simulation, visualization, animation, data import & export, … SOA : workflow management tools, data base front ends, data analysis, … the distributed software system based on HLA or SOA is dynamically created during run-time by special init sequences: HLA : Federation Management (Create & Destroy Federate Execution) SOA : Process Mapping on external services and Process Start- Event one general problem is performance : SOA turn-around time depends very from tool and differs between 20ms and 200 ms SOA focuses on Business process applications, but is used also for other apps. HLA focuses on military applications, but was used also for civilian apps. HLA und SOA - Wiedemann / HTW Dresden - Page 4
  5. 5. HLA The High-Level-Architecture (Source: Strassburger 2003 : Distributed Sim. (Diss.)) HLA und SOA - Wiedemann / HTW Dresden - Page 5
  6. 6. SOA Webservice 11 Webservice Webservice 22 Webservice Webservice 33 Webservice SOA –– SOA Webservice Webservice - -Ochestration XML XML Email Ochestration with with Enterprise – Service – Bus Rule- Rule- Interpeter Interpeter XML XML File Webservice 44 Webservice 44 Webservice 44 Webservice Webservice Webservice (Wrapper) (Wrapper) (Wrapper) (Wrapper) (Wrapper) (Wrapper) Application Application Application Application Application Application BPEL/ BPMN – Process descriptions A typical SOA-Webservice-orchestration infrastructure HLA und SOA - Wiedemann / HTW Dresden - Page 6
  7. 7. Main differences between HLA and SOA Historical roots and main world view HLA is partly based on older standards (DIS,ALSP) for distributed SIMULATION in military and defines a world view of objects SOA focuses on loosely coupled services, often realized by web services, and is relatively new (former standards like CORBA or RMI are not really predecessors) Time characteristics and main algorithms HLA can run faster than real time (main goal of simulation) and defines very complex time scheduling algorithms (optimistic sim.) SOA is implemented for scheduling services in real time and for execution of complex process logics (extraction of process logic from the applications into the Enterprise-Service-Bus-Logic-model) some SOA-constructs, like AND-Synchronisation (all processes must be finished before next step), are very similar to the conservative sim. HLA und SOA - Wiedemann / HTW Dresden - Page 7
  8. 8. Differences between HLA and SOA : Component Coupling HLA SOA a RTI-ambassador must be very loose coupling : only by included in each included data exchange and inter- software component (federate) pretation of (XML-) data in Object models (SOM/FOM) of service components all other FEDS must be exchange of components included in each federate during runtime WITHOUT changes in other components Webservice 11 Webservice Webservice 22 Webservice XML XML Enterprise – Service – Bus (Source: Strassburger 2003 : Distributed Sim. (Diss.)) HLA und SOA - Wiedemann / HTW Dresden - Page 8
  9. 9. Differences between HLA and SOA : Synchronization HLA SOA different and complex time in general : real time system management algorithms : if no component is time real time (with hardware in the dependent (e.g. booking loop-simulators) system with price depending near Real-time (faster run) on booking time ..), SOA can as fast as possible with run also as fast as possible conservative and optimistic time management very complex process- each component can act as management algorithms : timing master, slave or time synchrone & asynchron calls independent component with AND/ OR/ XOR – logic and while -loops Thesis & Question : Are AND-synchronized processes in SOA the same like a conservative simulation in HLA ? HLA und SOA - Wiedemann / HTW Dresden - Page 9
  10. 10. Differences between HLA and SOA : Ownership Management HLA SOA Objects and object attributes SOA data objects are are owned each step time by understood as business one federate documents : special ownership management Documents can be copied and be methods : “owned” by more than one process transfer of ownership lock mechanisms must be problems with ownership integrated by specific service management in parallel usage of components (like Data-Base objects (trainer /trainee want to locking algorithms) work on same object) Is HLA- ownership more secure ? Can they work together ? Is SOA ownership more flexible ? HLA und SOA - Wiedemann / HTW Dresden - Page 10
  11. 11. SOA process descriptions : BPMN & BPEL business logic is exposed to other software through standard services with the universal agreement on web services. Process orchestration is defined by BPEL and BPMN (no equivalent in HLA-RTI) BPEL (Business Process Execution Language) BPEL provides a standard, portable language for coordinating the flow of business process services and builds upon a decade of progress in the areas of business process management, workflow, and integration technologies. BPMN (Business Process Modeling Notation ) High-level graphical notation for business process modeling HLA und SOA - Wiedemann / HTW Dresden - Page 11
  12. 12. SOA – Tools : SOA –BPMN - Designer HLA und SOA - Wiedemann / HTW Dresden - Page 12
  13. 13. SOA – Tools : Bus -Designer HLA und SOA - Wiedemann / HTW Dresden - Page 13
  14. 14. SOA – Tools : generated BPEL model <partnerLink name="Approval" partnerRole="ApprovalPartnerRole" myRole="ApprovalMyRole" partnerLinkType="lns3:ApprovalLT" /> <partnerLink name="XOR" partnerRole="XORPartnerRole" myRole="XORMyRole" partnerLinkType="lns4:XORLT" /> <partnerLink name="client" partnerRole="provider" myRole="provider" partnerLinkType="tns:Purchase_Requisition_4 " /> <partnerLink name="Order" partnerRole="OrderPartnerRole" myRole="OrderMyRole" partnerLinkType="lns5:OrderLT" /> <partnerLink name="XOR" partnerRole="XORPartnerRole" myRole="XORMyRole" partnerLinkType="lns4:XORLT" /> <partnerLink name="Stop" partnerRole="StopPartnerRole" myRole="StopMyRole" partnerLinkType="lns6:StopLT" /> </partnerLinks> - <variables> <variable name="the_document" xmlns:asx="http://www.arrivosoft.com/bpel /asonia_extensions/" asx:var_guid="637fc4dc-993d-483d-bc76- ea874f0bbdeb" /> <variable name="Purchase Request" xmlns:asx="http://www.arrivosoft.com/bpel /asonia_extensions/" asx:var_guid="75fb1b32-dc61-4ae9-a00e- 7ded077e0b18" /> <variable name="Default Document" xmlns:asx="http://www.arrivosoft.com/bpel /asonia_extensions/" asx:var_guid="4b99fca1-a447-48c9-afff- 907dc5c41d63" /> <variable name="Default Document" xmlns:asx="http://www.arrivosoft.com/bpel /asonia_extensions/" asx:var_guid="d35ae97a-9c34-4aa1-b447- d366d8f5a913" /> <variable HLA und SOA - Wiedemann / HTW Dresden - Page 14
  15. 15. Interfaces between HLA and SOA ? 1. Data exchange HLA-data exchange between federates can be transferred to SOA-xml-messages and vice versa Mapping of messages could be automated 2. Ownership management HLA ownership management can be transferred to SOA-SERVICES SOA-”document ownership management” is more complex than HLA management (transfer with restrictions or workarounds) 3. Time management connected SOA-HLA- real time systems are possible faster as real SOA-HLA-Systems need an time management service in the SOA- Enterprise service bus and require applications without time dependencies in detail : SOA itself is capable “of faster than real”, the possible problems are inside the connected services and applications not a new situation for SIM: Also a lot of simulators is not ready for distributed time management strategies. solution for SOA: instead of using its own hardware-clock, a SOA-service should use a external web-service-clock, which could be manipulated for faster than real runs ! HLA und SOA - Wiedemann / HTW Dresden - Page 15
  16. 16. A HLA – SOA - infrastructure Webservice 11 Webservice Simulator 1 SOA –– SOA Web-Service Web-Service - -Orchestration Orchestration XML with with Enterprise – Service – Bus HLA – RTI Rule- Rule- Interpreter Interpreter XML XML Webservice 44 Webservice SOA ––CLOCK and SOA-Message-Connector SOA CLOCK and SOA-Message-Connector (Wrapper) (Wrapper) Animation Application Application SOA – HLA – Simulator 33 Message –Translator Simulator BPEL/ BPMN – Process By defining a JOINED – SOA –HLA –application descriptions NO CHANGES inside the HLA-RTI and SOA-ESB are necessary ! (should be confirmed by real tests !!!) A possible SOA-HLA - infrastructure HLA und SOA - Wiedemann / HTW Dresden - Page 16
  17. 17. The benefits of a HLA-SOA – connection SOA / BPM / BPEL approved standard, founded on years of work by ALL leading companies (IBM, Microsoft, Oracle, Sun, …. ) supports parallel, time dependent processes with empirical data, stochastic events and human interactions Advantages for Simulation & Modeling if we use SOA technologies, we will jump ON THE SAME TECHNOLGOY LEVEL like the IT frontiers one (!) SOA / BPEL – Model System software for control Simulation model of the real process Runtime - System HLA und SOA - Wiedemann / HTW Dresden - Page 17
  18. 18. SOA & BPM & BPEL : killer application in Simulation Implementation of large software packages (SAP / …) takes dozen months … years – factory & investment are waiting … solution : simulate factory inventory and start testing software TT =-12 months = - 9 months saved 12 months of T= 0 SAP - System introduction = 2...20 Million € !! Simulated Hardware 1 Real Hardware 1 Simulated Hardware 3 Real Hardware 3 (e.g. warehouse control system) (e.g. MES ) SOA – Enterprise - communication BUS Simulated Hardware 2 Real Hardware 2 Simulated Hardware 4 Real Hardware 4 (e.g. transport control system) (e.g. warehouse control system) HLA und SOA - Wiedemann / HTW Dresden - Page 18
  19. 19. Conclusion & Discussion • HLA and SOA focus both on distributed software systems • HLA is more simulation specific than SOA • SOA offers more flexibility, but lacks some specific simulation techniques • it seems possible, to integrate the missing time management and other techniques in SOA or to use SOA-HLA in a real time scenario together • by combining or connecting SOA and HLA, the simulation community could jump to a new level : Simulation as an integrated part of IT-Architectures for testing large business environments HLA und SOA - Wiedemann / HTW Dresden - Page 19
  20. 20. Discussion HLA und SOA - Wiedemann / HTW Dresden - Page 20

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