DDS in the E-ELT Technology Demonstrator Reynald Bourtembourg |

OpenSplice DDS evaluation Reynald Bourtembourg | Architecture DLRL Pluggable services Tools Editions Evolution of the DDS Standard

Architecture Reynald Bourtembourg |

DLRL (Data Local Reconstruction Layer) Reynald Bourtembourg | OpenSplice = only DDS implementation providing the DLRL Mapping relation Topic information model onto user defined object model OO programming interface  data-encapsulation  single inheritance  OO-language based object navigation Extra configuration steps to define the mapping objects- topics (xml file)

Pluggable services Reynald Bourtembourg | networking service durability service DDSI networking service (DDSI = interoperability protocol) DBMS-connect Connector  data exchange between DDS and any DBMS having ODBC v3 compliant interface Secure Networking (encrypted data)

Tools Reynald Bourtembourg | OpenSplice configurator mmstat DDS Tuner DDSTouchstone PowerTools MDE

OpenSplice DDS confgurator Reynald Bourtembourg |

mmstat Reynald Bourtembourg |

DDS Tuner Reynald Bourtembourg |

DDS Touchstone Reynald Bourtembourg | Scenario-driven Open Source benchmarking framework for evaluating performance of DDS implementations C, C++ and Java Transceivers – Transponders  Ping Pong communication  to measure jitter and latency Transmitters and Receivers  to measure throughput and efficiency Entities dynamically created, configured and destructed (DefTopic and QosTopic samples) Measurements published on ReportTopic DDS topic watcher and spotter tools to display the results Scenario manually created with DDS Tuner or using plain text scenario file Scenario can be replayed using recorder tool

PowerTools MDE Reynald Bourtembourg |

OpenSplice DDS Community Edition Reynald Bourtembourg | Mailing list:

Reynald Bourtembourg | OpenSplice DDS Compact Edition + support

Reynald Bourtembourg | OpenSplice DDS Professional Edition + support

Reynald Bourtembourg | OpenSplice DDS Enterprise Edition + support

OpenSplice DDS Editions Reynald Bourtembourg | x X (1) (1) Each subscription can choose from one of the supported platforms

Evolution of the DDS Standard Reynald Bourtembourg | New C++ API  in the revised submission stage  should be adopted soon (this year)  SIMD (SIMple DDS) project New Java API Extensible and Dynamic Topic Types for DDS (DDS- Xtypes) Web-enabled DDS  Standardization of the interface between DDS and web technologies, WSDL/SOAP and REST DDSI improvements

SIMD Reynald Bourtembourg | // -- SIMD Include #include #include #include #include // -- Hello Include #include "gen/ccpp_hello.h" // -- Define the types related to the swatch::hello topic // -- this will define the following types: // -- swatch::helloTypeSupport // -- swatch::helloDataWriter // -- swatch::helloDataReader // -- swatch::helloSeq REGISTER_TOPIC_TRAITS(swatch::hello) int main(int argc, char* argv[]) { // -- init the simd runtime simd::Runtime::init(); // -- Set topic QoS simd::TopicQos tqos; tqos.set_reliable(); tqos.set_transient(); // -- create the DDS Topic simd::Topic helloTopic("helloTopic", tqos); // -- Set DataWriter QoS simd::DataWriterQos dwqos(tqos); dwqos.set_keep_last(history_depth); dwqos.set_auto_dispose(false); // -- create the DDS DataWriter simd::DataWriter writer(helloTopic, dwqos); // -- Busines logic : swatch::hello sample; std::stringstream ss; for (int i = 0; i < N; ++i) { ss << i; std::string tmp = ss.str() + "." + message; ss.str(""); sample.name = DDS::string_dup(tmp.c_str()); std::cout << "<<= " << sample.name << std::endl; writer.write(sample); usleep(period*1000); } std::cout << "[done]" << std::endl; return 0; }

SIMD Reynald Bourtembourg | // -- SIMD Include #include #include #include #include // -- Hello Include #include "gen/ccpp_hello.h" REGISTER_TOPIC_TRAITS(swatch::hello) int main(int argc, char* argv[]) { // -- init the simd runtime simd::Runtime::init(); #include “ccpp_dds_dcps.h” #include “gen/ccpp_hello.h” int main( int argc, char * argv[]) { DomainParticipantFactory_var dpf; DomainParticipant_ptr parentDP; ExtDomainParticipant_var participant; /* Create a DomainParticipantFactory and a DomainParticipant (using Default QoS settings) */ dpf = DomainParticipantFactory::get_instance(); parentDP = dpf->create_participant ( domain, PARTICIPANT_QOS_DEFAULT, NULL, ANY_STATUS); /* Narrow the normal participant to its extended representative */ participant = ExtDomainParticipantImpl::_narrow(parentDP); } SIMDOpenSplice DDS

SIMD Reynald Bourtembourg | … // -- Set topic QoS simd::TopicQos tqos; tqos.set_reliable(); tqos.set_transient(); // -- create the DDS Topic simd::Topic helloTopic("helloTopic", tqos); HelloTypeSupport_var helloTS; char * helloTypeName = NULL; ReturnCode_t status; TopicQos topic_qos; /* Register the required datatype for hello. */ helloTS = new HelloTypeSupport(); helloTypeName = helloTS->get_type_name(); status = helloTS->register_type( participant.in(), helloTypeName); /* Set the ReliabilityQosPolicy to RELIABLE. */ status = participant->get_default_topic_qos(topic_qos); topic_qos.reliability.kind = DDS::RELIABLE_RELIABILITY_QOS; topic_qos. durability.kind = DDS::TRANSIENT_DURABILITY_QOS; /* Create the DDS topic */ helloTopic = participant->create_topic( “hello Topic", helloTypeName, topic_qos, NULL, ANY_STATUS); SIMDOpenSplice DDS

Evolution of the DDS Standard Reynald Bourtembourg | Extensible and Dynamic Topic Types for DDS (DDS-XTypes):  API for definition of new data types at run-time without code generation  A reflective API for the construction, inspection, and manipulation of data samples based on dynamic type definitions  Ability to define data types using XML and XSD as well  Topics sparse updates (send only the modified fields)

Evolution of the DDS Standard Reynald Bourtembourg | DDSI improvements:  Support of non multicast discovery  Possibility to go through TCP/IP  Support compression of messages  Concept of queues

Interoperability tests Reynald Bourtembourg | Interoperable protocol Source code compatibility Unbounded IDL types Reliable large data transfer Interoperability tests (Open Splice DDS 4.2 – RTI DDS 4.4d)

Interoperable protocol Reynald Bourtembourg | RTI DDS supports DDSI natively Configuration needed in OpenSplice DDS (ddsi network service) Using DDSI slightly decreases OpenSplice DDS performances DDS Domain issues (RTI DDS = id, OpenSplice DDS = path to xml file) OpenSplice DDS 4.3 limitations:  Only Best EFFORT reliability QoS implemented  Only VOLATILE durability QoS implemented  Fragmentation of large messages not implemented  QoS modifications after creation not possible  Standard discovery requires multicast (only discovery specified in the DDSI standard)

Source code compatibility Reynald Bourtembourg | DDS Standard specifies only the IDL No Standard C++ API (will come soon)  DDS:string_dup() - DDS:String_dup()  in() and inout() methods for sequences only in RTI DDS  OpenSplice DDS generates code defining new types  Constructors defined as private (Compilation pbs) Keys definition in IDL files - #pragma keylist)

Unbounded IDL types Reynald Bourtembourg | unbounded string default size in RTI DDS = 255 bytes -stringSize rtiddsgen option to change the assigned size no such limitation in OpenSplice DDS

Reliable data transfer Reynald Bourtembourg | RTI DDS requires asynchronous publisher to send data larger than 63K (ASYNCHRONOUS_PUBLISHER QoS policy) in OpenSplice DDS, (ddsi) network service is responsible for fragmenting, scheduling and send data through the network The samples sent must fit in the reserved shared memory segment (default = 10MB) fragmentation not yet supported by the OpenSplice DDS ddsi service

Interoperability tests Reynald Bourtembourg | PingPong application from OpenSplice DDS examples ported to RTI DDS RTI DDS 4.4d and OpenSplice DDS 4.2 Community Edition Success in exchanging data between RTI DDS and OpenSplice DDS applications Failure in exchanging data between RTI DDS and OpenSplice DDS applications running on the same machine Warning: log files in OpenSplice DDS can become big very quickly (OSPL_INFO_FILE, OSPL_LOG_PATH, OSPL_ERROR_FILE env variables) Interoperability demonstrated at the OMG:  Using a beta version of OpenSplice DDS.  No test on the same machine

OpenSplice DDS Evaluation: Conclusion Reynald Bourtembourg | Interesting open source alternative to RTI DDS Very flexible and extendable architecture based on service daemons Daemons must be robust DDS Tuner seems to be very useful Power Tools MDE can increase productivity Only implementation providing the DLRL, but not really needed Interoperability does not work yet new C++ PSM should provide better source code compatibility

TDEM Reynald Bourtembourg | Architecture RTI DDS CORBA Compatibility Kit Google Protocol Buffers and DDS

TDEM: Architecture Reynald Bourtembourg |

TDEM: RTI DDS CORBA Compatibility Kit Reynald Bourtembourg | to be able to use CORBA data types in DDS several limitations: Cannot pass a.midl file to rtiddsgen Could not pass a.idl file generated from a.midl file to rtiddsgen removed) if an idl file includes another idl file, we need to generate code for all these include files with rtiddsgen include not supported by rtiddsgen We could not reuse the same idl file as the one used with OpenDDS Cannot mix declaration of structures used only with CORBA and structures used by DDS and CORBA. rtiddsgen generates code for every structure present in the file

TDEM: Google Protocol Buffers Reynald Bourtembourg | package tutorial; message Person { required string name = 1; required int32 id = 2; optional string = 3; enum PhoneType { MOBILE = 0; HOME = 1; WORK = 2; } message PhoneNumber { required string number = 1; optional PhoneType type = 2 [default = HOME]; } repeated PhoneNumber phone = 4; } // end message Person message AddressBook { repeated Person person = 1; }

TDEM: Google Protocol Buffers Reynald Bourtembourg | tutorial::AddressBook address_book; { // Read the existing address book. fstream input(argv[1], ios::in | ios::binary); if (!address_book.ParseFromIstream(&input)) { cerr << "Failed to parse address book." << endl; return -1; } } for (int i = 0; i < address_book.person_size(); i++) { const tutorial::Person& person = address_book.person(i); cout << "Person ID: " << person.id() << endl; cout << " Name: " << person.name() << endl; if (person.has_ ()) { cout << " address: " << person. () << endl; } for (int j = 0; j < person.phone_size(); j++) { const tutorial::Person::PhoneNumber& phone_number = person.phone(j); switch (phone_number.type()) { case tutorial::Person::MOBILE: cout << " Mobile phone #: “ << phone_number.number() << endl;...

TDEM: Google Protocol Buffers & DDS Reynald Bourtembourg | send Google Protocol Buffers messages with DDS typedef sequence SeqOctets; struct gpb_message { SeqOctets gpb_data; };

TDEM: Google Protocol Buffers & DDS Reynald Bourtembourg | if we use DDS, data should not be opaque to DDS (Content filtering, sparse updates in the future) DDS XTypes should provide the same advantages

Reynald Bourtembourg | Thank you for your attention! Questions?