Angelo Corsaro, profile picture
Uploaded byAngelo Corsaro
3,071 views

Advanced OpenSplice Programming - Part II

The document provides an in-depth exploration of OpenSplice DDS programming, focusing on advanced concepts and Quality of Service (QoS) policies that manage data distribution in distributed applications. It discusses various components such as data writers and readers, the importance of local caches, dynamic discovery, and the implementation details for C++ and Java APIs. Additionally, it outlines the types of durability, reliability, and their impact on the data availability and handling in various scenarios.

Embed presentation

Downloaded 175 times
Advanced OpenSplice DDS Programming - Part II - OpenSplice DDS Angelo CORSARO, Ph.D. Chief Technology Officer OMG DDS Sig Co-Chair PrismTech angelo.corsaro@prismtech.com
Part I - Recap OpenSplice DDS
Key Concepts to Remember ☐ OpenSplice DDS provides a mechanism for efficiently sharing user- Copyright  2011,  PrismTech  –    All  Rights  Reserved. defined data among distributed applications and network connected devices OpenSplice DDS Agricultural Vehicle Systems Large Scale SCADA Systems Smart Cities Train Control Systems Complex Medical Devices Big Data (In-Memory) Analytics
Key Concepts to Remember ☐ OpenSplice DDS allows to build distributed systems by reasoning in Copyright  2011,  PrismTech  –    All  Rights  Reserved. terms of application types as opposed to messages OpenSplice DDS TopicA TopicE ... TopicB TopicD TopicC OpenSplice DDS Global Data Space PS. long in IDL is a 32 bit integer
Key Concepts to Remember ☐ User defined data types are accessible through “local caches”. Copyright  2011,  PrismTech  –    All  Rights  Reserved. These local caches can have a depth and store multiple updates for the same data item OpenSplice DDS
Key Concepts to Remember Copyright  2011,  PrismTech  –    All  Rights  Reserved. ☐ Built-in dynamic discovery automatically establishes associations between data writers and data readers Data Reader Data OpenSplice DDS Writer Data Reader Data TopicD Writer TopicA Data TopicB Reader Data Writer TopicC ... Data Data Writer Reader DDS Global Data Space
Anatomy of a DDS Application [DDS C++ API 2010] Domain Domain Copyright  2011,  PrismTech  –    All  Rights  Reserved. auto dp = DomainParticipant(domainId); Participant Session // Create a Topic Publisher Topic Subscriber OpenSplice DDS auto topic = Topic<ShapeType>(dp, “Circle”); // Create a Publisher / Subscriber auto pub = Publisher(dp); auto sub = Subscriber(dp); Reader/Writers for User Defined for Types DataWriter DataReader // Create a DataWriter/DataWriter auto writer = DataWriter<ShapeType>(pub, topic); Reader/Writer for auto reader = DataReader<ShapeType>(sub, topic); application defined Topic Types
Anatomy of a DDS Application [DDS C++ API 2010] Domain Domain Copyright  2011,  PrismTech  –    All  Rights  Reserved. auto  dp  =  DomainParticipant(domainId);   Participant Session //  Create  a  Topic Publisher Topic Subscriber OpenSplice DDS auto  topic  =  Topic<ShapeType>(dp,  “Circle”); //  Create  a  Publisher  /  Subscriber auto  pub  =  Publisher(dp); auto  sub  =  Subscriber(dp); Reader/Writers for User Defined for Types DataWriter DataReader //  Write  data writer.write(ShapeType(“RED”,  131,  107,  89)); Reader/Writer for //  But  you  can  also  write  like  this... application defined writer  <<  ShapeType(“RED”,  131,  107,  89); Topic Types //  Read  new  data  (loaned) auto  data  =  reader.read();
Anatomy of a DDS Application [DDS Java 5 API 2010] Domain Domain Copyright  2011,  PrismTech  –    All  Rights  Reserved. DomainParticipantFactory  factory  =  DomainParticipantFactory.getInstance(env); DomainParticipant  dp  =  factory.createParticipant(); Participant Session //  Create  a  Topic Topic<ShapeType>  topic  = Publisher Topic Subscriber OpenSplice DDS      dp.createParticipant(“Circle”,  ShapeType.class); //  Create  a  Publisher  /  Subscriber Publisher    pub  =  dp.createPublisher(); Subscriber  sub  =  dp.createSubscriber(); Reader/Writers for User Defined for Types DataWriter DataReader //  Create  a  DataWriter/DataWriter DataWriter<ShapeType>  dw  =pub.createDataWriter(topic);   Reader/Writer for DataReader<ShapeType>  dr  =pub.createDataReader(topic);   application defined Topic Types
Anatomy of a DDS Application [DDS Java 5 API 2010] Domain Domain Copyright  2011,  PrismTech  –    All  Rights  Reserved. DomainParticipantFactory  factory  =  DomainParticipantFactory.getInstance(env); DomainParticipant  dp  =  factory.createParticipant(); Participant Session //  Create  a  Topic Topic<ShapeType>  topic  = Publisher Topic Subscriber OpenSplice DDS      dp.createParticipant(“Circle”,  ShapeType.class); //  Create  a  Publisher  /  Subscriber Publisher    pub  =  dp.createPublisher(); Subscriber  sub  =  dp.createSubscriber(); Reader/Writers for User Defined for Types DataWriter DataReader //  write  data dw.write(new  ShapeType(“RED”,  10,  20,  50);   Reader/Writer for //  read  data application defined Sample.Iterator<ShapeType>  data  =  dr.read(); Topic Types
OpenSplice DDS Part II
Quality of Service OpenSplice DDS
QoS Model ☐ QoS-Policies control local and end-to-end properties of DDS Copyright  2011,  PrismTech  –    All  Rights  Reserved. Type Matching entities QoS matching QoS QoS QoS QoS QoS QoS QoS ☐ Local properties controlled by Topic Name QoS are related resource usage Publisher Subscriber ... DataWriter writes Type reads DataReader ... OpenSplice DDS ... ☐ End-to-end properties DomainParticipant DataWriter writes Type reads DataReader DomainParticipant controlled by QoS are related Topic Name to temporal and spatial aspects QoS QoS QoS of data distribution ☐ Some QoS-Policies are matched based on a Request vs. Offered Model thus QoS-enforcement
QoS Policies [T: Topic] [DR: DataReader] [DW: DataWriter] [P: Publisher] [S: Subscriber] [DP: Domain Participant] QoS Policy Applicability RxO Modifiable Copyright  2011,  PrismTech  –    All  Rights  Reserved. USER_DATA DP, DR, DW N Y TOPIC_DATA T N Y Configuration GROUP_DATA P, S N Y DURABILITY T, DR, DW Y N OpenSplice DDS DURABILITY T, DW N N SERVICE Data Availability HISTORY T, DR, DW N N PRESENTATION P, S Y N RELIABILITY T, DR, DW Y N PARTITION P, S N Y Data Delivery DESTINATION T, DR, DW Y N ORDER LIFESPAN T, DW N Y
QoS Policies [T: Topic] [DR: DataReader] [DW: DataWriter] [P: Publisher] [S: Subscriber] [DP: Domain Participant] QoS Policy Applicability RxO Modifiable Copyright  2011,  PrismTech  –    All  Rights  Reserved. DEADLINE T, DR, DW Y Y LATENCY T, DR, DW Y Y BUDGET Temporal/ TRANSPORT T, DW N Y Importance PRIORITY Characteristics OpenSplice DDS TIME BASED DR N Y FILTER OWNERSHIP T, DR, DW Y N OWNERSHIP DW N Y Replication STRENGTH LIVELINESS T, DR, DW Y N Fault-Detection
OpenSplice DDS Partition Data Delivery Reliability Presentation Data Delivery Order Destination Copyright  2011,  PrismTech  –    All  Rights  Reserved.
Reliability QoS Policy QoS Policy Applicability RxO Modifiable RELIABILITY T, DR, DW Y N Copyright  2011,  PrismTech  –    All  Rights  Reserved. The Reliability Policy controls the level of guarantee offered by the DDS in delivering data to subscribers ☐ Reliable. In steady-state, and no data writer crashes, the OpenSplice DDS middleware guarantees that all samples in the DataWriter history will eventually be delivered to all the DataReader ☐ Best Effort. Indicates that it is acceptable to not retry propagation of any samples
Setting the Reliability Policy [DDS C++ API 2010] Copyright  2011,  PrismTech  –    All  Rights  Reserved. DataWriterQos  dwqos  =        pub.default_datawriter_qos()  <<  Reliability.Reliable(); OpenSplice DDS -­‐  or  -­‐ DataWriterQos  dwqos  =        pub.default_datawriter_qos()  <<  Reliability.BestEffort();
Setting the Partition Policy [DDS Java 5 API 2010] Copyright  2011,  PrismTech  –    All  Rights  Reserved. final  PolicyFactory  pf  =  ... DataWriterQos  dwqos  =        pub.getDefaultDataWriterQos() OpenSplice DDS            .withPolicies(pf.Reliability.withReliable());   -­‐  or  -­‐ DataWriterQos  dwqos  =        pub.getDefaultDataWriterQos()            .withPolicies(pf.Reliability.withBestEffort());  
Partition QoS Policy QoS Policy Applicability RxO Modifiable ☐ The Partition QoS Policy can PARTITION P, S N Y Copyright  2011,  PrismTech  –    All  Rights  Reserved. be used as subjects for organizing the flows of data ☐ The Partition QoS Policy is Subscriber used to connect Publishers/ Publisher "tracks.kfo" "tracks.ufo" OpenSplice DDS Subscribers to a Partitions’ List which might also contain wildcards, e.g. Subscriber Publisher tracks.* ☐ Topics instances are published and subscribed Publisher Subscriber across one or more Partition Partitions
Setting the Partition Policy [DDS C++ API 2010] Copyright  2011,  PrismTech  –    All  Rights  Reserved. PublisherQos  pqos  =        dp.default_publisher_qos()  <<  Partition(“MyPartition”); OpenSplice DDS -­‐  or  -­‐ PublisherQos  pqos  =        dp.default_publisher_qos()  <<  Partition(myPartitionList);
Setting the Partition Policy [DDS Java 5 API 2010] Copyright  2011,  PrismTech  –    All  Rights  Reserved. final  PolicyFactory  pf  =  ... PublisherQos  pqos  =        dp.getDefaultPublisherQos() OpenSplice DDS            .withPolicies(pf.Partition(“MyPartition”));   -­‐  or  -­‐ PublisherQos  pqos  =        dp.getDefaultPublisherQos()            .withPolicies(pf.Partition(myPartitionList));  
Data Availability History Copyright  2011,  PrismTech  –    All  Rights  Reserved. Data OpenSplice DDS Lifespan Durability Availability Ownership Ownership Strength
Durability QoS Policy QoS Policy Applicability RxO Modifiable DURABILITY T, DR, DW Y N Copyright  2011,  PrismTech  –    All  Rights  Reserved. The DURABILITY QoS controls the data availability w.r.t. late joiners, specifically the DDS provides the following variants: ☐ Volatile. No need to keep data instances for late joining data readers OpenSplice DDS ☐ Transient Local. Data instance availability for late joining data reader is tied to the data writer availability ☐ Transient. Data instance availability outlives the data writer ☐ Persistent. Data instance availability outlives system restarts
Volatile Data Writer Copyright  2011,  PrismTech  –    All  Rights  Reserved. 1 TopicA Data Reader OpenSplice DDS DDS Global Data Space ‣ No Time Decoupling ‣ Readers get only data produced after they joined the Global Data Space
Volatile Late Joiner Data Data Reader Writer Copyright  2011,  PrismTech  –    All  Rights  Reserved. TopicA Data Reader OpenSplice DDS 1 DDS Global Data Space ‣ No Time Decoupling ‣ Readers get only data produced after they joined the Global Data Space
Volatile Data Data Reader Writer Copyright  2011,  PrismTech  –    All  Rights  Reserved. 2 TopicA Data Reader OpenSplice DDS 1 DDS Global Data Space ‣ No Time Decoupling ‣ Readers get only data produced after they joined the Global Data Space
Transient Local Data Writer Copyright  2011,  PrismTech  –    All  Rights  Reserved. 1 TopicA Data Reader OpenSplice DDS DDS Global Data Space ‣ Some Time Decoupling ‣ Data availability is tied to the availability of the data writer and the history settings
Transient Local Late Joiner Data Data Reader Writer Copyright  2011,  PrismTech  –    All  Rights  Reserved. 1 TopicA Data Reader OpenSplice DDS 1 DDS Global Data Space ‣ Some Time Decoupling ‣ Data availability is tied to the availability of the data writer and the history settings
Transient Local Data Data Reader Writer Copyright  2011,  PrismTech  –    All  Rights  Reserved. 1 1 2 TopicA Data Reader OpenSplice DDS 1 DDS Global Data Space ‣ Some Time Decoupling ‣ Data availability is tied to the availability of the data writer and the history settings
Transient Data Writer Copyright  2011,  PrismTech  –    All  Rights  Reserved. 1 TopicA Data Reader OpenSplice DDS DDS Global Data Space ‣ Time Decoupling ‣ Data availability is tied to the availability of the durability service -- a fully distributed fault-tolerant service in the case of OpenSplice DDS.
Transient Late Joiner Data Data Reader Writer Copyright  2011,  PrismTech  –    All  Rights  Reserved. TopicA 1 Data Reader OpenSplice DDS 1 DDS Global Data Space ‣ Time Decoupling ‣ Data availability is tied to the availability of the durability service -- a fully distributed fault-tolerant service in the case of OpenSplice DDS.
Transient Data Reader Copyright  2011,  PrismTech  –    All  Rights  Reserved. 1 TopicA 1 Data Reader OpenSplice DDS 1 DDS Global Data Space ‣ Time Decoupling ‣ Data availability is tied to the availability of the durability service -- a fully distributed fault-tolerant service in the case of OpenSplice DDS.
Transient Data Reader Copyright  2011,  PrismTech  –    All  Rights  Reserved. 1 TopicA 1 Data Reader OpenSplice DDS 1 Data Reader DDS Global Data Space Late Joiner ‣ Time Decoupling ‣ Data availability is tied to the availability of the durability service -- a fully distributed fault-tolerant service in the case of OpenSplice DDS.
History QoS Policy QoS Policy Applicability RxO Modifiable HISTORY T, DR, DW N N Copyright  2011,  PrismTech  –    All  Rights  Reserved. For DataWriters, the HISTORY QoS policy controls the amount of data that can be made available to late joining DataReaders under TRANSIENT_LOCAL Durability OpenSplice DDS For DataReader, the HISTORY QoS policy controls how many samples will be kept on the reader cache ☐ Keep Last. DDS will keep the most recent “depth” samples of each instance of data identified by its key ☐ Keep All. The DDS keep all the samples of each instance of data identified by its key -- up to reaching some configurable resource limits
Ownership QoS Policy QoS Policy Applicability RxO Modifiable OWNERSHIP T, DR, DW Y N STRENGTH DW N Y Copyright  2011,  PrismTech  –    All  Rights  Reserved. Availability of data producers can be controlled via two QoS Policies ☐ OWNERSHIP (SHARED vs. EXCLUSIVE) OpenSplice DDS ☐ OWNERSHIP STRENGTH ☐ Instances of exclusively owned Topics can be modified (are owned) by the higher strength writer ☐ Writer strength is used to coordinate replicated writers
Temporal Properties Copyright  2011,  PrismTech  –    All  Rights  Reserved. TimeBasedFilter Deadline [Inbound] OpenSplice DDS Throughput LatencyBudget Latency [Outbound] TransportPriority
Latency Budget QoS Policy QoS Policy Applicability RxO Modifiable LATENCY T, DR, DW Y Y ☐ The LATENCY_BUDGET QoS BUDGET Copyright  2011,  PrismTech  –    All  Rights  Reserved. policy specifies the maximum acceptable delay from the time the data is written until the data OpenSplice DDS is inserted in the receiver's application-cache Latency = T1+T2+T3 DataWriter T3 DataReader ☐ A non-zero latency-budget T1 allows a DDS Batching implementation to batch T2 samples and improve CPU/ Network utilization
Deadline QoS Policy QoS Policy Applicability RxO Modifiable DEADLINE T, DR, DW Y Y Copyright  2011,  PrismTech  –    All  Rights  Reserved. ☐ The DEADLINE QoS policy allows to define the maximum inter-arrival time between data samples ☐ DataWriter indicates that the application commits to write a new OpenSplice DDS value at least once every deadline period ☐ DataReaders are notified by the DDS when the DEADLINE QoS contract is violated DataWriter Deadline Deadline Deadline Deadline Deadline DataReader Deadline Violation
Transport Priority QoS Policy QoS Policy Applicability RxO Modifiable TRANSPORT T, DW N Y PRIORITY Copyright  2011,  PrismTech  –    All  Rights  Reserved. ☐ The TRANSPORT_PRIORITY QoS policy is a hint to the infrastructure as OpenSplice DDS to how to set the priority of the underlying transport used to send the data.
Time-Based Filter QoS Policy QoS Policy Applicability RxO Modifiable TIME BASED DR N Y FILTER Copyright  2011,  PrismTech  –    All  Rights  Reserved. mit mit ☐ The Time Based Filter allows to control the throughput at which Latency = T1+T2+T3 data is received by a data reader OpenSplice DDS DataWriter T3 DataReader ☐ Samples produced more often T2 than the minimum inter-arrival time are not delivered to the data reader mit mit mit = minimum inter-arrival time produced sample delivered sample discarded sample
QoS Provider ☐ The new C++ and Java APIs introduce the concept of a QoS Copyright  2011,  PrismTech  –    All  Rights  Reserved. Provider ☐ This class allows to externally define policies and decouples the mechanism used to define and access policy definition with policy OpenSplice DDS creation            //  QosProvider...            QosProvider  qos_provider(                        "http://www.opensplice.org/demo/config/qos.xml",                        "ishapes-­‐profile");            DataReader<ShapeType>  dr(sub,  topic,  qos_provider.datareader_qos());
QoS and Data Modeling OpenSplice DDS Patterns
Soft State ☐ In distributed systems you often need to model soft-state -- a state Copyright  2011,  PrismTech  –    All  Rights  Reserved. that is periodically updated ☐ Examples are the reading of a sensor (e.g. Temperature Sensor), the position of a vehicle, etc. OpenSplice DDS ☐ The QoS combination to model Soft-State is the following: Reliability            =>    BestEffort Durability              =>    Volatile   History                    =>    KeepLast(n)  [with  n  =  1  in  most  of  the  cases] Deadline                  =>    updatePeriod LatencyBudget        =>    updatePeriod/3  [rule  of  thumb] DestinationOrder  =>    SourceTimestamp  [if  multiple  writers  per  instance]
Hard State ☐ In distributed systems you often need to model hard-state -- a state Copyright  2011,  PrismTech  –    All  Rights  Reserved. that is sporadically updated and that often has temporal persistence requirements ☐ Examples are system configuration, a price estimate, etc. OpenSplice DDS ☐ The QoS combination to model Hard-State is the following: Reliability            =>    Reliable Durability              =>    Transient  |  Persistent   History                    =>    KeepLast(n)  [with  n  =  1  in  most  of  the  cases] DestinationOrder  =>    SourceTimestamp  [if  multiple  writers  per  instance]
Events ☐ In distributed systems you often need to model events -- the occurrence of something noteworthy for our system Copyright  2011,  PrismTech  –    All  Rights  Reserved. ☐ Examples are a collision alert, the temperature beyond a given threshold, etc. OpenSplice DDS ☐ The QoS combination to model Events is the following: Reliability            =>    Reliable Durability              =>    any                [depends  on  system  requirements]   History                    =>    KeepAll  [on  both  DataWriter  and  DataReader!] DestinationOrder  =>    SourceTimestamp
Streams Copyright  2011,  PrismTech  –    All  Rights  Reserved. ☐ At times you need to deal with high volumes of frequently changing soft-state ☐ You may have from several hundreds of thousands to several OpenSplice DDS millions of data readings that need to be distributed in your system... Where each reading is usually from few tends to few hundreds of bytes ☐ OpenSplice provide a special abstraction to deal with this situation called Streams
Streams struct SCADASensor { long sid; float value; }; #pragma stream SCADASensor ☐ OpenSplice Streams Copyright  2011,  PrismTech  –    All  Rights  Reserved. transparently perform batching and un- High Frequency High Frequency batching of data based Samples Samples on samples count or OpenSplice DDS time StreamDataWriter StreamDataReader ☐ OpenSplice Streams Batching Un-Batching also provide explicit Temporal or Samples-Count flush operation to force Driven Batching the middleware to send data
StreamDataWriter Copyright  2011,  PrismTech  –    All  Rights  Reserved. StreamDataWriterQos  sqos(max_samples,  max_delay); SCADASensorStreamDataWriter  sdw  =        new  SCADASensorStreamDataWriter(did,  sqos,  “ScadaSensorT”); OpenSplice DDS StreamId  sid  =  0;  //  Your  stream  Id SCADASensor  data  =  ... sdw.append(sid,  data); ... //  Explicitely  flush  the  stream sdw.flush(sid);
StreamDataReader Copyright  2011,  PrismTech  –    All  Rights  Reserved. SCADASensorStreamDataReader  sdr  =        new  SCADASensorStreamDataReader(did,  “ScadaSensorT”); StreamId  sid  =  0;  //  Your  stream  Id SCADASensorSeq  data; OpenSplice DDS //  Issue  a  blocking  get sdw.get(sid,  data,  DDS::LENGTH_UNLIMITED,  DDS::DURATION_INFINITE); //  Note:   //    -­‐  get_with_filter  is  also  available  to  filter  data //    -­‐  The  Stream  Examples  are  shown  using  the  DDS  C++  2004  API   //        since  these  are  OpenSplice  specific  extensions.   //        DDS  C++  2010  counterparts  will  be  soon  available.
Resource Management OpenSplice DDS
LongVariable Example ☐ The “distributed” version of the following code: Copyright  2011,  PrismTech  –    All  Rights  Reserved. int  x; int  y; x  =  10; y  =  20; OpenSplice DDS Topic Type ☐ Becomes: // Create a Publisher struct LongVariable { auto lvt = Topic<LongVariable>(dp, “TLongVariable”); @Key string name; // Create DataWriters long value; auto dw = DataWriter<LongVariable>(pub, topic); }; // Write Data dw.write(LongVariable(“x”,10)); dw.write(LongVariable(“y”,20)); PS. long in IDL is a 32 bit integer
Looking with the Spyglass Copyright  2011,  PrismTech  –    All  Rights  Reserved. Topic TLongValue struct LongVariable { @Key string name; long value; OpenSplice DDS dw }; Policies name value x 10 y 20
Declaration vs. Assignement Copyright  2011,  PrismTech  –    All  Rights  Reserved. Assignment {   Declaration    int  x; dw.write(LongVariable(“x”,10));    x  =  10; Assignment OpenSplice DDS } Resources Reclamation ☐ Can we declare topic instances in DDS? ☐ Can we control resource reclamation?
Instance Registration Copyright  2011,  PrismTech  –    All  Rights  Reserved. {   auto key = LongVariable(“x”,0) Declaration    int  x; auto handle = Declaration    x  =  10; dw.register_instance(key); Assignment OpenSplice DDS } dw.write(LongVariable(“x”,10)); Assignment Resources Reclamation ☐ Instance registration provides a way of informing the system that the given data writer will be writing the given instance ☐ This operation has an impact on instance life-cycle ☐ The write operation implicitly register the instance being written, if necessary
Instance Un-registration ☐ DDS provides a way for a DataWriter to “un-register” an Copyright  2011,  PrismTech  –    All  Rights  Reserved. instance thus informing the system that he won’t be writing that specific instance any more This operation has an impact on instance life-cycle OpenSplice DDS ☐ dw.unregister_instance(handle);
Instance Disposal auto key = LongVariable(“x”,0) {   Declaration auto handle = Copyright  2011,  PrismTech  –    All  Rights  Reserved. Declaration    int  x; dw.register_instance(key);    x  =  10; } Assignment dw.write(LongVariable(“x”,10)); dw.dispose_instance(handle) Assignment OpenSplice DDS Resources Reclamation Resources Reclamation ☐ Allows to control resource reclamation for a given instance. ☐ The action of disposing an instance signifies that the system is done with it...
Writer Data Lifecycle The life-cycle of data on the Writer side is controlled by means of Copyright  2011,  PrismTech  –    All  Rights  Reserved. ☐ QoS policy we’ve not introduced yet, the WriterDataLifecycle ☐ This policy controls wether unregistered instances are automatically OpenSplice DDS disposed or not ☐ This is quite important since when a writer is disposed all its instances are automatically unregistered and depending on the setting of this QoS might also be disposed... Which in some cases is not what you want!
Reader Data Lifecycle ☐ The lifecycle of the data-instances received by the DataReader is Copyright  2011,  PrismTech  –    All  Rights  Reserved. controlled by the ReaderDataLifecycle policy ☐ This policy allow to control two properties ☐ autopurge_nowriter_samples_delay: the maximum duration for OpenSplice DDS which the DataReader will maintain information on an instance once its state becomes NOT_ALIVE_NO_WRITERS ☐ autopurge_disposed_samples_delay: the maximum duration for which the DataReader will maintain samples for an instance once its state becomes NOT_ALIVE_DISPOSED PS. The default setting for this policy is INFINITE for both delays
DDS and Functional Programming OpenSplice DDS
Why Functional Programming (FP)? Some of the main reasons for the steep increase in the adoption of Functional Copyright  2011,  PrismTech  –    All  Rights  Reserved. Programming languages are: ☐ Referential Transparency (no side effects): makes it easier to write reusable code and facilitates concurrency (increasingly more important due to multi- cores) OpenSplice DDS ☐ Declarative style: makes code easier to understand (once you understand the language) ☐ Higher Order abstractions: Higher order functions, pattern matching, algebraic data types, Higher Kinds, makes it easier to express solutions in our domain ☐ Domain Specific Languages (DSL): Functional programming languages like Haskel and Scala make it easy to develop DSLs
Why DDS and FP? ☐ Data Centricity and Stream Computing match very naturally with Copyright  2011,  PrismTech  –    All  Rights  Reserved. functional programming ☐ All of a sudden your system can be easily modeled as streams of data transformed by composable functions OpenSplice DDS ☐ Referential transparency makes it easily parallelizable F(x) G(y,z)
struct  TempSensor  { Example      long  id;      float  temp;      float  hum; }; #pragma  keylist  TempSensor  id Compute the moving average for temperature and humidity Copyright  2011,  PrismTech  –    All  Rights  Reserved. ☐ val  tst    =  Topic[TempSensor]("TempSensorT") val  atst  =  Topic[TempSensor]("AverageTempSensorT") OpenSplice DDS val  rqos  =  DataReaderQos()  <=  History.KeepLast(windowSize) val  dr  =  DataReader[TempSensor](tst,  rqos) val  dw  =  DataWriter[TempSensor](atst) reader.reactions  +=  {    case  DataAvailable(_)  =>  {                val  window  =  dr.history.data        val  tempAvg  =  (0F  /:  window)(_  +  _.temp)  /  window.length        val  humAvg    =  (0F  /:  window)(_  +  _.hum)  /  window.length        dw  !  new  TempSensor(-­‐1,  tempAvg,  humAvg)      } }
List Comprehension OpenSplice DDS
List Comprehension in DDS Copyright  2011,  PrismTech  –    All  Rights  Reserved. ☐ When using the SCALA API, the DDS readers expose data as LinearSeqOptimized thus making possible list comprehension to address quite a few task OpenSplice DDS ☐ Example ☐ dr read foreach (println) ☐ dr read map (transformer) ☐ ...
Examples Compute the average shape and write it as a Gray Square: Copyright  2011,  PrismTech  –    All  Rights  Reserved. ☐ val data = dr history val s0 = new ShapeType(“GRAY”, 0, 0 ,0) OpenSplice DDS dw ! scaleShape((s0 /: data) (sumShape), data.size) ☐ Filter samples: (dr read) filter (_.x <= 100 && _.y <= 200)
OpenSplice DDS References
DDS ISO C++ API 2010 Copyright  2011,  PrismTech  –    All  Rights  Reserved. ☐ github.com/kydos ☐ New C++ API OpenSplice DDS ☐ Demo applications ☐ Alpha reference implementation (simd-cxx) ☐ online docs ☐ kydos.github.com/dds-psm-cxx/
OpenSplice DDS ☐ ☐ ☐ New Java API github.com/kydos Demo applications DDS Java 5 API 2010 Copyright  2011,  PrismTech  –    All  Rights  Reserved.
DDS Scala API Copyright  2011,  PrismTech  –    All  Rights  Reserved. ☐ github.com/kydos ☐ Scala API for DDS Set of demo showing how OpenSplice DDS ☐ the API can be used ☐ Notice that this API can also be used for scripting DDS applications
OpenSplice DDS Summing Up
Concluding Remarks OpenSplice DDS provides a very powerful abstraction for building Copyright  2011,  PrismTech  –    All  Rights  Reserved. ☐ distributed applications grounded on the concept of a fully distributed global data space OpenSplice DDS ☐ Topics are used to define the types that populate the global data space while DataWriters and DataReaders are used to produce and consume values ☐ DataReaders allow very flexible data access through cache access operations
OpenSplice DDS
References Copyright  2011,  PrismTech  –    All  Rights  Reserved. OpenSplice | DDS Escalier ¥ #1 OMG DDS Implementation ¥ Fastest growing JVM Language ¥ Scala API for OpenSplice DDS ¥ Open Source ¥ Open Source ¥ Open Source ¥ www.opensplice.org ¥ www.scala-lang.org ¥ github.com/kydos/escalier OpenSplice DDS ¥ Simple C++ API for DDS ¥ DDS-PSM-Java for OpenSplice DDS ¥ DDS-based Advanced Distributed ¥ Open Source ¥ Open Source Algorithms Toolkit ¥ github.com/kydos/simd-cxx ¥ github.com/kydos/simd-java ¥ Open Source ¥ github.com/kydos/dada
:: Connect with Us :: ¥opensplice.com ¥forums.opensplice.org ¥@acorsaro ¥opensplice.org ¥opensplicedds@prismtech.com ¥@prismtech OpenSplice DDS ¥ crc@prismtech.com ¥sales@prismtech.com ¥youtube.com/opensplicetube ¥slideshare.net/angelo.corsaro

More Related Content

PDF
OpenSplice DDS Tutorial -- Part II
byAngelo Corsaro
 
PDF
The Data Distribution Service Tutorial
byAngelo Corsaro
 
PDF
DDS in Action -- Part I
byAngelo Corsaro
 
PDF
The DDS Security Standard
byAngelo Corsaro
 
PDF
Cybersecurity Roadmap for Beginners
bySanjeev Kumar Jaiswal
 
PDF
RTI DDS Intro with DDS Secure
byJohn Breitenbach
 
PDF
Tiering AD : Comment procéder après le Tier0 ?
byIdentity Days
 
PPTX
منظومة إدارة السجناء | تحليل وتصميم نظم
byAlaref Abushaala
 
OpenSplice DDS Tutorial -- Part II
byAngelo Corsaro
 
The Data Distribution Service Tutorial
byAngelo Corsaro
 
DDS in Action -- Part I
byAngelo Corsaro
 
The DDS Security Standard
byAngelo Corsaro
 
Cybersecurity Roadmap for Beginners
bySanjeev Kumar Jaiswal
 
RTI DDS Intro with DDS Secure
byJohn Breitenbach
 
Tiering AD : Comment procéder après le Tier0 ?
byIdentity Days
 
منظومة إدارة السجناء | تحليل وتصميم نظم
byAlaref Abushaala
 

What's hot

PDF
Lyne - Occult ether physics.pdf
byGodsExecutioner
 
PDF
10 Reasons for Choosing OpenSplice DDS
byAngelo Corsaro
 
PDF
MITRE ATT&CK Updates: State of the ATT&CK (ATT&CKcon 4.0 Edition)
byMITRE ATT&CK
 
PPTX
secure file Storage on cloud ppt
byNishmithaHc
 
PPTX
Continuous Automated Red Teaming (CART) - Bikash Barai
byAllanGray11
 
PPTX
Tanium Overview
byJordanTough
 
PDF
Data Leakage Prevention (DLP)
byNetwork Intelligence India
 
PPT
Knowledge agenda
byIntegrated Knowledge Services
 
PPTX
Setting up a secure development life cycle with OWASP - seba deleersnyder
bySebastien Deleersnyder
 
PPTX
Cyber threat Intelligence and Incident Response by:-Sandeep Singh
byOWASP Delhi
 
PPTX
What is network detection and response?
byVehere
 
PPTX
Database Security Management
byAhsin Yousaf
 
PPTX
Exploring Frameworks of Splunk Enterprise Security
bySplunk
 
PPTX
Comparison of MQTT and DDS as M2M Protocols for the Internet of Things
byReal-Time Innovations (RTI)
 
PDF
TITUS - Top Reasons For Data Classification
byJohn Timmerman
 
PPT
CONTENT DELIVERY NETWORK
bySaif Muttair
 
PDF
Perspectives on Cloud COmputing - Google
byACMBangalore
 
PDF
Network Security - Defense Through Layered Information Security
byEryk Budi Pratama
 
PPTX
system Security
byGaurav Mishra
 
PPTX
Seminar on pervasive computing
byLikan Patra
 
Lyne - Occult ether physics.pdf
byGodsExecutioner
 
10 Reasons for Choosing OpenSplice DDS
byAngelo Corsaro
 
MITRE ATT&CK Updates: State of the ATT&CK (ATT&CKcon 4.0 Edition)
byMITRE ATT&CK
 
secure file Storage on cloud ppt
byNishmithaHc
 
Continuous Automated Red Teaming (CART) - Bikash Barai
byAllanGray11
 
Tanium Overview
byJordanTough
 
Data Leakage Prevention (DLP)
byNetwork Intelligence India
 
Knowledge agenda
byIntegrated Knowledge Services
 
Setting up a secure development life cycle with OWASP - seba deleersnyder
bySebastien Deleersnyder
 
Cyber threat Intelligence and Incident Response by:-Sandeep Singh
byOWASP Delhi
 
What is network detection and response?
byVehere
 
Database Security Management
byAhsin Yousaf
 
Exploring Frameworks of Splunk Enterprise Security
bySplunk
 
Comparison of MQTT and DDS as M2M Protocols for the Internet of Things
byReal-Time Innovations (RTI)
 
TITUS - Top Reasons For Data Classification
byJohn Timmerman
 
CONTENT DELIVERY NETWORK
bySaif Muttair
 
Perspectives on Cloud COmputing - Google
byACMBangalore
 
Network Security - Defense Through Layered Information Security
byEryk Budi Pratama
 
system Security
byGaurav Mishra
 
Seminar on pervasive computing
byLikan Patra
 

Viewers also liked

PDF
Advanced OpenSplice Programming - Part I
byAngelo Corsaro
 
PDF
DDS QoS Unleashed
byAngelo Corsaro
 
PDF
The DDS Tutorial - Part I
byAngelo Corsaro
 
PDF
The DDS Tutorial Part II
byAngelo Corsaro
 
PDF
Getting Started in DDS with C++ and Java
byAngelo Corsaro
 
PDF
20 Tips for OpenSplice Newbies
byAngelo Corsaro
 
PDF
DDS Tutorial -- Part I
byAngelo Corsaro
 
PDF
Vortex Tutorial -- Part I
byAngelo Corsaro
 
PDF
Stream Processing with DDS and CEP
byAngelo Corsaro
 
PDF
Getting Started with OpenSplice DDS Community Ed.
byAngelo Corsaro
 
PDF
OpenSplice DDS v6
byAngelo Corsaro
 
PDF
Introducing Vortex Lite
byAngelo Corsaro
 
PDF
Vortex Tutorial Part II
byAngelo Corsaro
 
PDF
Building Reactive Applications with DDS
byAngelo Corsaro
 
PDF
Building and Scaling Internet of Things Applications with Vortex Cloud
byAngelo Corsaro
 
PDF
Building Real-Time Web Applications with Vortex-Web
byAngelo Corsaro
 
PDF
Desktop, Embedded and Mobile Apps with Vortex Café
byAngelo Corsaro
 
PDF
Connected Mobile and Web Applications with Vortex
byAngelo Corsaro
 
PDF
Getting Started with Vortex
byAngelo Corsaro
 
PPTX
Mixing for Broadcast and Film
byrecordingtutorialsonline
 
Advanced OpenSplice Programming - Part I
byAngelo Corsaro
 
DDS QoS Unleashed
byAngelo Corsaro
 
The DDS Tutorial - Part I
byAngelo Corsaro
 
The DDS Tutorial Part II
byAngelo Corsaro
 
Getting Started in DDS with C++ and Java
byAngelo Corsaro
 
20 Tips for OpenSplice Newbies
byAngelo Corsaro
 
DDS Tutorial -- Part I
byAngelo Corsaro
 
Vortex Tutorial -- Part I
byAngelo Corsaro
 
Stream Processing with DDS and CEP
byAngelo Corsaro
 
Getting Started with OpenSplice DDS Community Ed.
byAngelo Corsaro
 
OpenSplice DDS v6
byAngelo Corsaro
 
Introducing Vortex Lite
byAngelo Corsaro
 
Vortex Tutorial Part II
byAngelo Corsaro
 
Building Reactive Applications with DDS
byAngelo Corsaro
 
Building and Scaling Internet of Things Applications with Vortex Cloud
byAngelo Corsaro
 
Building Real-Time Web Applications with Vortex-Web
byAngelo Corsaro
 
Desktop, Embedded and Mobile Apps with Vortex Café
byAngelo Corsaro
 
Connected Mobile and Web Applications with Vortex
byAngelo Corsaro
 
Getting Started with Vortex
byAngelo Corsaro
 
Mixing for Broadcast and Film
byrecordingtutorialsonline
 

Similar to Advanced OpenSplice Programming - Part II

PDF
Tuning and Troubleshooting OpenSplice DDS Applications
byAngelo Corsaro
 
PDF
Classical Distributed Algorithms with DDS
byAngelo Corsaro
 
PDF
Getting Started with DDS in C++, Java and Scala
byAngelo Corsaro
 
PDF
Distributed Simulations with DDS and HLA
byAngelo Corsaro
 
PDF
DDS-PSM-Cxx and simd-cxx
byAngelo Corsaro
 
PPTX
SimWare Rti: HLA raised to the power of DDS
byJosé Ramón Martínez Salio
 
PDF
The Present and Future of DDS
byAngelo Corsaro
 
PDF
OpenSplice DDS v5.1
byAngelo Corsaro
 
PDF
SimD
byAngelo Corsaro
 
PDF
Roadmap and Technology Incubators
byAngelo Corsaro
 
PDF
Hibernating DDS
byAngelo Corsaro
 
PPTX
SimWare and the new LSA study group on SISO
byJosé Ramón Martínez Salio
 
PDF
Got Big Data? Get OpenSplice!
byAngelo Corsaro
 
PDF
Cloudand Xchange
bySkills Matter
 
PDF
Tweeting with OpenSplice DDS
byAngelo Corsaro
 
PDF
OpenSplice Security Module
byAngelo Corsaro
 
PPTX
SIMWARE RTI : HLA powered by DDS
bySimware
 
PPTX
Simware RTI: Hello World!
byJose Carlos Diaz
 
PPTX
SimWare rti hello world: Webinar
byJosé Ramón Martínez Salio
 
PDF
High Performance Distributed Computing with DDS and Scala
byAngelo Corsaro
 
Tuning and Troubleshooting OpenSplice DDS Applications
byAngelo Corsaro
 
Classical Distributed Algorithms with DDS
byAngelo Corsaro
 
Getting Started with DDS in C++, Java and Scala
byAngelo Corsaro
 
Distributed Simulations with DDS and HLA
byAngelo Corsaro
 
DDS-PSM-Cxx and simd-cxx
byAngelo Corsaro
 
SimWare Rti: HLA raised to the power of DDS
byJosé Ramón Martínez Salio
 
The Present and Future of DDS
byAngelo Corsaro
 
OpenSplice DDS v5.1
byAngelo Corsaro
 
SimD
byAngelo Corsaro
 
Roadmap and Technology Incubators
byAngelo Corsaro
 
Hibernating DDS
byAngelo Corsaro
 
SimWare and the new LSA study group on SISO
byJosé Ramón Martínez Salio
 
Got Big Data? Get OpenSplice!
byAngelo Corsaro
 
Cloudand Xchange
bySkills Matter
 
Tweeting with OpenSplice DDS
byAngelo Corsaro
 
OpenSplice Security Module
byAngelo Corsaro
 
SIMWARE RTI : HLA powered by DDS
bySimware
 
Simware RTI: Hello World!
byJose Carlos Diaz
 
SimWare rti hello world: Webinar
byJosé Ramón Martínez Salio
 
High Performance Distributed Computing with DDS and Scala
byAngelo Corsaro
 

More from Angelo Corsaro

PDF
The Data Distribution Service
byAngelo Corsaro
 
PDF
Cyclone DDS: Sharing Data in the IoT Age
byAngelo Corsaro
 
PDF
zenoh: The Edge Data Fabric
byAngelo Corsaro
 
PDF
zenoh -- the ZEro Network OverHead protocol
byAngelo Corsaro
 
PDF
zenoh: zero overhead pub/sub store/query compute
byAngelo Corsaro
 
PDF
Breaking the Edge -- A Journey Through Cloud, Edge and Fog Computing
byAngelo Corsaro
 
PDF
Zenoh: The Genesis
byAngelo Corsaro
 
PDF
zenoh -- the ZEro Network OverHead protocol
byAngelo Corsaro
 
PDF
Zenoh Tutorial
byAngelo Corsaro
 
PDF
Data Sharing in Extremely Resource Constrained Envionrments
byAngelo Corsaro
 
PDF
Programming in Scala - Lecture One
byAngelo Corsaro
 
PDF
fog05: The Fog Computing Infrastructure
byAngelo Corsaro
 
PDF
Programming in Scala - Lecture Two
byAngelo Corsaro
 
PDF
Programming in Scala - Lecture Three
byAngelo Corsaro
 
PDF
Vortex II -- The Industrial IoT Connectivity Standard
byAngelo Corsaro
 
PDF
Data Decentralisation: Efficiency, Privacy and Fair Monetisation
byAngelo Corsaro
 
PDF
fog05: The Fog Computing Platform
byAngelo Corsaro
 
PDF
RUSTing -- Partially Ordered Rust Programming Ruminations
byAngelo Corsaro
 
PDF
Programming in Scala - Lecture Four
byAngelo Corsaro
 
PDF
Eastern Sicily
byAngelo Corsaro
 
The Data Distribution Service
byAngelo Corsaro
 
Cyclone DDS: Sharing Data in the IoT Age
byAngelo Corsaro
 
zenoh: The Edge Data Fabric
byAngelo Corsaro
 
zenoh -- the ZEro Network OverHead protocol
byAngelo Corsaro
 
zenoh: zero overhead pub/sub store/query compute
byAngelo Corsaro
 
Breaking the Edge -- A Journey Through Cloud, Edge and Fog Computing
byAngelo Corsaro
 
Zenoh: The Genesis
byAngelo Corsaro
 
zenoh -- the ZEro Network OverHead protocol
byAngelo Corsaro
 
Zenoh Tutorial
byAngelo Corsaro
 
Data Sharing in Extremely Resource Constrained Envionrments
byAngelo Corsaro
 
Programming in Scala - Lecture One
byAngelo Corsaro
 
fog05: The Fog Computing Infrastructure
byAngelo Corsaro
 
Programming in Scala - Lecture Two
byAngelo Corsaro
 
Programming in Scala - Lecture Three
byAngelo Corsaro
 
Vortex II -- The Industrial IoT Connectivity Standard
byAngelo Corsaro
 
Data Decentralisation: Efficiency, Privacy and Fair Monetisation
byAngelo Corsaro
 
fog05: The Fog Computing Platform
byAngelo Corsaro
 
RUSTing -- Partially Ordered Rust Programming Ruminations
byAngelo Corsaro
 
Programming in Scala - Lecture Four
byAngelo Corsaro
 
Eastern Sicily
byAngelo Corsaro
 

Recently uploaded

PPTX
AI: Beyond Generative AI and LLM | Harrie de Groot (harrie.dev)
byHarrie de Groot
 
PDF
Running Non-Cloud-Native Databases in Cloud-Native Environments_ Challenges a...
byAlkin Tezuysal
 
PDF
UiPath DevConnect 2025: UiPath ScreenPlay - The Future of Human-Like Automation
byDianaGray10
 
PDF
Building a Multi-Tenant OpenShift Platform with HyperShift
byTosin Akinosho
 
PDF
Supervised Machine Learning Approaches for Log-Based Anomaly Detection: A Cas...
byMohammed BEKKOUCHE
 
PDF
Beyond Basics: How to Build Scalable, Intelligent Imagery Pipelines
bySafe Software
 
PDF
Raj Jain, Recent Advances, Issues, and Challenges in Cybersecurity, Keynote a...
byrjain51
 
PPTX
Neo4j Fraud GraphTalk Singapore Nov 2025
bygourisachdeva2
 
PDF
KMWorld - KM & AI Bring Collectivity, Nostalgia, & Selectivity
byJonathan Ralton
 
PDF
Dev Dives: Build smarter agents with UiPath Agent Builder
byUiPathCommunity
 
PDF
UiPath DevConnect 2025: UiPath ScreenPlay - The Future of Human-Like Automation
byDianaGray10
 
PDF
Mutation Testing for Industrial Robotic Systems (FMAS 2025)
bySylvain Hallé
 
PDF
Building Powerful Web Apps to Improve Productivity and Engagement - Esri UK W...
byEsri UK
 
PDF
THE THREATS OF INSTABILITY IN BRAZIL'S INTERCONNECTED ELECTRICAL SYSTEM AND H...
byFaga1939
 
PDF
AWS Cloud Technical Essentials - AWS Certificate
byVICTOR MAESTRE RAMIREZ
 
PDF
UnityNet AI Induced Harm & Youth Protection Position Statement 2025-11-15
byLHelferty
 
PDF
Linux Foundation Certified System Administrator (LFCS) Exam.pdf
byLinuxCert Guru
 
PPTX
Redcentric Data Centres: vision, mission and values
byRedcentric
 
PDF
SELinux Basics: Managing SELinux Modes and Context - RHCSA+.pdf
byLinuxCert Guru
 
PPTX
Understanding the digital experience of FE teaching staff in 2024/25
byJisc
 
AI: Beyond Generative AI and LLM | Harrie de Groot (harrie.dev)
byHarrie de Groot
 
Running Non-Cloud-Native Databases in Cloud-Native Environments_ Challenges a...
byAlkin Tezuysal
 
UiPath DevConnect 2025: UiPath ScreenPlay - The Future of Human-Like Automation
byDianaGray10
 
Building a Multi-Tenant OpenShift Platform with HyperShift
byTosin Akinosho
 
Supervised Machine Learning Approaches for Log-Based Anomaly Detection: A Cas...
byMohammed BEKKOUCHE
 
Beyond Basics: How to Build Scalable, Intelligent Imagery Pipelines
bySafe Software
 
Raj Jain, Recent Advances, Issues, and Challenges in Cybersecurity, Keynote a...
byrjain51
 
Neo4j Fraud GraphTalk Singapore Nov 2025
bygourisachdeva2
 
KMWorld - KM & AI Bring Collectivity, Nostalgia, & Selectivity
byJonathan Ralton
 
Dev Dives: Build smarter agents with UiPath Agent Builder
byUiPathCommunity
 
UiPath DevConnect 2025: UiPath ScreenPlay - The Future of Human-Like Automation
byDianaGray10
 
Mutation Testing for Industrial Robotic Systems (FMAS 2025)
bySylvain Hallé
 
Building Powerful Web Apps to Improve Productivity and Engagement - Esri UK W...
byEsri UK
 
THE THREATS OF INSTABILITY IN BRAZIL'S INTERCONNECTED ELECTRICAL SYSTEM AND H...
byFaga1939
 
AWS Cloud Technical Essentials - AWS Certificate
byVICTOR MAESTRE RAMIREZ
 
UnityNet AI Induced Harm & Youth Protection Position Statement 2025-11-15
byLHelferty
 
Linux Foundation Certified System Administrator (LFCS) Exam.pdf
byLinuxCert Guru
 
Redcentric Data Centres: vision, mission and values
byRedcentric
 
SELinux Basics: Managing SELinux Modes and Context - RHCSA+.pdf
byLinuxCert Guru
 
Understanding the digital experience of FE teaching staff in 2024/25
byJisc
 

Advanced OpenSplice Programming - Part II

  • 1.
    Advanced OpenSplice DDS Programming - Part II - OpenSplice DDS Angelo CORSARO, Ph.D. Chief Technology Officer OMG DDS Sig Co-Chair PrismTech angelo.corsaro@prismtech.com
  • 2.
    Part I -Recap OpenSplice DDS
  • 3.
    Key Concepts toRemember ☐ OpenSplice DDS provides a mechanism for efficiently sharing user- Copyright  2011,  PrismTech  –    All  Rights  Reserved. defined data among distributed applications and network connected devices OpenSplice DDS Agricultural Vehicle Systems Large Scale SCADA Systems Smart Cities Train Control Systems Complex Medical Devices Big Data (In-Memory) Analytics
  • 4.
    Key Concepts toRemember ☐ OpenSplice DDS allows to build distributed systems by reasoning in Copyright  2011,  PrismTech  –    All  Rights  Reserved. terms of application types as opposed to messages OpenSplice DDS TopicA TopicE ... TopicB TopicD TopicC OpenSplice DDS Global Data Space PS. long in IDL is a 32 bit integer
  • 5.
    Key Concepts toRemember ☐ User defined data types are accessible through “local caches”. Copyright  2011,  PrismTech  –    All  Rights  Reserved. These local caches can have a depth and store multiple updates for the same data item OpenSplice DDS
  • 6.
    Key Concepts toRemember Copyright  2011,  PrismTech  –    All  Rights  Reserved. ☐ Built-in dynamic discovery automatically establishes associations between data writers and data readers Data Reader Data OpenSplice DDS Writer Data Reader Data TopicD Writer TopicA Data TopicB Reader Data Writer TopicC ... Data Data Writer Reader DDS Global Data Space
  • 7.
    Anatomy of aDDS Application [DDS C++ API 2010] Domain Domain Copyright  2011,  PrismTech  –    All  Rights  Reserved. auto dp = DomainParticipant(domainId); Participant Session // Create a Topic Publisher Topic Subscriber OpenSplice DDS auto topic = Topic<ShapeType>(dp, “Circle”); // Create a Publisher / Subscriber auto pub = Publisher(dp); auto sub = Subscriber(dp); Reader/Writers for User Defined for Types DataWriter DataReader // Create a DataWriter/DataWriter auto writer = DataWriter<ShapeType>(pub, topic); Reader/Writer for auto reader = DataReader<ShapeType>(sub, topic); application defined Topic Types
  • 8.
    Anatomy of aDDS Application [DDS C++ API 2010] Domain Domain Copyright  2011,  PrismTech  –    All  Rights  Reserved. auto  dp  =  DomainParticipant(domainId);   Participant Session //  Create  a  Topic Publisher Topic Subscriber OpenSplice DDS auto  topic  =  Topic<ShapeType>(dp,  “Circle”); //  Create  a  Publisher  /  Subscriber auto  pub  =  Publisher(dp); auto  sub  =  Subscriber(dp); Reader/Writers for User Defined for Types DataWriter DataReader //  Write  data writer.write(ShapeType(“RED”,  131,  107,  89)); Reader/Writer for //  But  you  can  also  write  like  this... application defined writer  <<  ShapeType(“RED”,  131,  107,  89); Topic Types //  Read  new  data  (loaned) auto  data  =  reader.read();
  • 9.
    Anatomy of aDDS Application [DDS Java 5 API 2010] Domain Domain Copyright  2011,  PrismTech  –    All  Rights  Reserved. DomainParticipantFactory  factory  =  DomainParticipantFactory.getInstance(env); DomainParticipant  dp  =  factory.createParticipant(); Participant Session //  Create  a  Topic Topic<ShapeType>  topic  = Publisher Topic Subscriber OpenSplice DDS      dp.createParticipant(“Circle”,  ShapeType.class); //  Create  a  Publisher  /  Subscriber Publisher    pub  =  dp.createPublisher(); Subscriber  sub  =  dp.createSubscriber(); Reader/Writers for User Defined for Types DataWriter DataReader //  Create  a  DataWriter/DataWriter DataWriter<ShapeType>  dw  =pub.createDataWriter(topic);   Reader/Writer for DataReader<ShapeType>  dr  =pub.createDataReader(topic);   application defined Topic Types
  • 10.
    Anatomy of aDDS Application [DDS Java 5 API 2010] Domain Domain Copyright  2011,  PrismTech  –    All  Rights  Reserved. DomainParticipantFactory  factory  =  DomainParticipantFactory.getInstance(env); DomainParticipant  dp  =  factory.createParticipant(); Participant Session //  Create  a  Topic Topic<ShapeType>  topic  = Publisher Topic Subscriber OpenSplice DDS      dp.createParticipant(“Circle”,  ShapeType.class); //  Create  a  Publisher  /  Subscriber Publisher    pub  =  dp.createPublisher(); Subscriber  sub  =  dp.createSubscriber(); Reader/Writers for User Defined for Types DataWriter DataReader //  write  data dw.write(new  ShapeType(“RED”,  10,  20,  50);   Reader/Writer for //  read  data application defined Sample.Iterator<ShapeType>  data  =  dr.read(); Topic Types
  • 11.
  • 12.
  • 13.
    QoS Model ☐ QoS-Policies control local and end-to-end properties of DDS Copyright  2011,  PrismTech  –    All  Rights  Reserved. Type Matching entities QoS matching QoS QoS QoS QoS QoS QoS QoS ☐ Local properties controlled by Topic Name QoS are related resource usage Publisher Subscriber ... DataWriter writes Type reads DataReader ... OpenSplice DDS ... ☐ End-to-end properties DomainParticipant DataWriter writes Type reads DataReader DomainParticipant controlled by QoS are related Topic Name to temporal and spatial aspects QoS QoS QoS of data distribution ☐ Some QoS-Policies are matched based on a Request vs. Offered Model thus QoS-enforcement
  • 14.
    QoS Policies [T: Topic] [DR: DataReader] [DW: DataWriter] [P: Publisher] [S: Subscriber] [DP: Domain Participant] QoS Policy Applicability RxO Modifiable Copyright  2011,  PrismTech  –    All  Rights  Reserved. USER_DATA DP, DR, DW N Y TOPIC_DATA T N Y Configuration GROUP_DATA P, S N Y DURABILITY T, DR, DW Y N OpenSplice DDS DURABILITY T, DW N N SERVICE Data Availability HISTORY T, DR, DW N N PRESENTATION P, S Y N RELIABILITY T, DR, DW Y N PARTITION P, S N Y Data Delivery DESTINATION T, DR, DW Y N ORDER LIFESPAN T, DW N Y
  • 15.
    QoS Policies [T: Topic] [DR: DataReader] [DW: DataWriter] [P: Publisher] [S: Subscriber] [DP: Domain Participant] QoS Policy Applicability RxO Modifiable Copyright  2011,  PrismTech  –    All  Rights  Reserved. DEADLINE T, DR, DW Y Y LATENCY T, DR, DW Y Y BUDGET Temporal/ TRANSPORT T, DW N Y Importance PRIORITY Characteristics OpenSplice DDS TIME BASED DR N Y FILTER OWNERSHIP T, DR, DW Y N OWNERSHIP DW N Y Replication STRENGTH LIVELINESS T, DR, DW Y N Fault-Detection
  • 16.
    OpenSplice DDS Partition Data Delivery Reliability Presentation Data Delivery Order Destination Copyright  2011,  PrismTech  –    All  Rights  Reserved.
  • 17.
    Reliability QoS Policy QoS Policy Applicability RxO Modifiable RELIABILITY T, DR, DW Y N Copyright  2011,  PrismTech  –    All  Rights  Reserved. The Reliability Policy controls the level of guarantee offered by the DDS in delivering data to subscribers ☐ Reliable. In steady-state, and no data writer crashes, the OpenSplice DDS middleware guarantees that all samples in the DataWriter history will eventually be delivered to all the DataReader ☐ Best Effort. Indicates that it is acceptable to not retry propagation of any samples
  • 18.
    Setting the ReliabilityPolicy [DDS C++ API 2010] Copyright  2011,  PrismTech  –    All  Rights  Reserved. DataWriterQos  dwqos  =        pub.default_datawriter_qos()  <<  Reliability.Reliable(); OpenSplice DDS -­‐  or  -­‐ DataWriterQos  dwqos  =        pub.default_datawriter_qos()  <<  Reliability.BestEffort();
  • 19.
    Setting the PartitionPolicy [DDS Java 5 API 2010] Copyright  2011,  PrismTech  –    All  Rights  Reserved. final  PolicyFactory  pf  =  ... DataWriterQos  dwqos  =        pub.getDefaultDataWriterQos() OpenSplice DDS            .withPolicies(pf.Reliability.withReliable());   -­‐  or  -­‐ DataWriterQos  dwqos  =        pub.getDefaultDataWriterQos()            .withPolicies(pf.Reliability.withBestEffort());  
  • 20.
    Partition QoS Policy QoS Policy Applicability RxO Modifiable ☐ The Partition QoS Policy can PARTITION P, S N Y Copyright  2011,  PrismTech  –    All  Rights  Reserved. be used as subjects for organizing the flows of data ☐ The Partition QoS Policy is Subscriber used to connect Publishers/ Publisher "tracks.kfo" "tracks.ufo" OpenSplice DDS Subscribers to a Partitions’ List which might also contain wildcards, e.g. Subscriber Publisher tracks.* ☐ Topics instances are published and subscribed Publisher Subscriber across one or more Partition Partitions
  • 21.
    Setting the PartitionPolicy [DDS C++ API 2010] Copyright  2011,  PrismTech  –    All  Rights  Reserved. PublisherQos  pqos  =        dp.default_publisher_qos()  <<  Partition(“MyPartition”); OpenSplice DDS -­‐  or  -­‐ PublisherQos  pqos  =        dp.default_publisher_qos()  <<  Partition(myPartitionList);
  • 22.
    Setting the PartitionPolicy [DDS Java 5 API 2010] Copyright  2011,  PrismTech  –    All  Rights  Reserved. final  PolicyFactory  pf  =  ... PublisherQos  pqos  =        dp.getDefaultPublisherQos() OpenSplice DDS            .withPolicies(pf.Partition(“MyPartition”));   -­‐  or  -­‐ PublisherQos  pqos  =        dp.getDefaultPublisherQos()            .withPolicies(pf.Partition(myPartitionList));  
  • 23.
    Data Availability History Copyright  2011,  PrismTech  –    All  Rights  Reserved. Data OpenSplice DDS Lifespan Durability Availability Ownership Ownership Strength
  • 24.
    Durability QoS Policy QoS Policy Applicability RxO Modifiable DURABILITY T, DR, DW Y N Copyright  2011,  PrismTech  –    All  Rights  Reserved. The DURABILITY QoS controls the data availability w.r.t. late joiners, specifically the DDS provides the following variants: ☐ Volatile. No need to keep data instances for late joining data readers OpenSplice DDS ☐ Transient Local. Data instance availability for late joining data reader is tied to the data writer availability ☐ Transient. Data instance availability outlives the data writer ☐ Persistent. Data instance availability outlives system restarts
  • 25.
    Volatile Data Writer Copyright  2011,  PrismTech  –    All  Rights  Reserved. 1 TopicA Data Reader OpenSplice DDS DDS Global Data Space ‣ No Time Decoupling ‣ Readers get only data produced after they joined the Global Data Space
  • 26.
    Volatile Late Joiner Data Data Reader Writer Copyright  2011,  PrismTech  –    All  Rights  Reserved. TopicA Data Reader OpenSplice DDS 1 DDS Global Data Space ‣ No Time Decoupling ‣ Readers get only data produced after they joined the Global Data Space
  • 27.
    Volatile Data Data Reader Writer Copyright  2011,  PrismTech  –    All  Rights  Reserved. 2 TopicA Data Reader OpenSplice DDS 1 DDS Global Data Space ‣ No Time Decoupling ‣ Readers get only data produced after they joined the Global Data Space
  • 28.
    Transient Local Data Writer Copyright  2011,  PrismTech  –    All  Rights  Reserved. 1 TopicA Data Reader OpenSplice DDS DDS Global Data Space ‣ Some Time Decoupling ‣ Data availability is tied to the availability of the data writer and the history settings
  • 29.
    Transient Local Late Joiner Data Data Reader Writer Copyright  2011,  PrismTech  –    All  Rights  Reserved. 1 TopicA Data Reader OpenSplice DDS 1 DDS Global Data Space ‣ Some Time Decoupling ‣ Data availability is tied to the availability of the data writer and the history settings
  • 30.
    Transient Local Data Data Reader Writer Copyright  2011,  PrismTech  –    All  Rights  Reserved. 1 1 2 TopicA Data Reader OpenSplice DDS 1 DDS Global Data Space ‣ Some Time Decoupling ‣ Data availability is tied to the availability of the data writer and the history settings
  • 31.
    Transient Data Writer Copyright  2011,  PrismTech  –    All  Rights  Reserved. 1 TopicA Data Reader OpenSplice DDS DDS Global Data Space ‣ Time Decoupling ‣ Data availability is tied to the availability of the durability service -- a fully distributed fault-tolerant service in the case of OpenSplice DDS.
  • 32.
    Transient Late Joiner Data Data Reader Writer Copyright  2011,  PrismTech  –    All  Rights  Reserved. TopicA 1 Data Reader OpenSplice DDS 1 DDS Global Data Space ‣ Time Decoupling ‣ Data availability is tied to the availability of the durability service -- a fully distributed fault-tolerant service in the case of OpenSplice DDS.
  • 33.
    Transient Data Reader Copyright  2011,  PrismTech  –    All  Rights  Reserved. 1 TopicA 1 Data Reader OpenSplice DDS 1 DDS Global Data Space ‣ Time Decoupling ‣ Data availability is tied to the availability of the durability service -- a fully distributed fault-tolerant service in the case of OpenSplice DDS.
  • 34.
    Transient Data Reader Copyright  2011,  PrismTech  –    All  Rights  Reserved. 1 TopicA 1 Data Reader OpenSplice DDS 1 Data Reader DDS Global Data Space Late Joiner ‣ Time Decoupling ‣ Data availability is tied to the availability of the durability service -- a fully distributed fault-tolerant service in the case of OpenSplice DDS.
  • 35.
    History QoS Policy QoS Policy Applicability RxO Modifiable HISTORY T, DR, DW N N Copyright  2011,  PrismTech  –    All  Rights  Reserved. For DataWriters, the HISTORY QoS policy controls the amount of data that can be made available to late joining DataReaders under TRANSIENT_LOCAL Durability OpenSplice DDS For DataReader, the HISTORY QoS policy controls how many samples will be kept on the reader cache ☐ Keep Last. DDS will keep the most recent “depth” samples of each instance of data identified by its key ☐ Keep All. The DDS keep all the samples of each instance of data identified by its key -- up to reaching some configurable resource limits
  • 36.
    Ownership QoS Policy QoS Policy Applicability RxO Modifiable OWNERSHIP T, DR, DW Y N STRENGTH DW N Y Copyright  2011,  PrismTech  –    All  Rights  Reserved. Availability of data producers can be controlled via two QoS Policies ☐ OWNERSHIP (SHARED vs. EXCLUSIVE) OpenSplice DDS ☐ OWNERSHIP STRENGTH ☐ Instances of exclusively owned Topics can be modified (are owned) by the higher strength writer ☐ Writer strength is used to coordinate replicated writers
  • 37.
    Temporal Properties Copyright  2011,  PrismTech  –    All  Rights  Reserved. TimeBasedFilter Deadline [Inbound] OpenSplice DDS Throughput LatencyBudget Latency [Outbound] TransportPriority
  • 38.
    Latency Budget QoSPolicy QoS Policy Applicability RxO Modifiable LATENCY T, DR, DW Y Y ☐ The LATENCY_BUDGET QoS BUDGET Copyright  2011,  PrismTech  –    All  Rights  Reserved. policy specifies the maximum acceptable delay from the time the data is written until the data OpenSplice DDS is inserted in the receiver's application-cache Latency = T1+T2+T3 DataWriter T3 DataReader ☐ A non-zero latency-budget T1 allows a DDS Batching implementation to batch T2 samples and improve CPU/ Network utilization
  • 39.
    Deadline QoS Policy QoS Policy Applicability RxO Modifiable DEADLINE T, DR, DW Y Y Copyright  2011,  PrismTech  –    All  Rights  Reserved. ☐ The DEADLINE QoS policy allows to define the maximum inter-arrival time between data samples ☐ DataWriter indicates that the application commits to write a new OpenSplice DDS value at least once every deadline period ☐ DataReaders are notified by the DDS when the DEADLINE QoS contract is violated DataWriter Deadline Deadline Deadline Deadline Deadline DataReader Deadline Violation
  • 40.
    Transport Priority QoSPolicy QoS Policy Applicability RxO Modifiable TRANSPORT T, DW N Y PRIORITY Copyright  2011,  PrismTech  –    All  Rights  Reserved. ☐ The TRANSPORT_PRIORITY QoS policy is a hint to the infrastructure as OpenSplice DDS to how to set the priority of the underlying transport used to send the data.
  • 41.
    Time-Based Filter QoSPolicy QoS Policy Applicability RxO Modifiable TIME BASED DR N Y FILTER Copyright  2011,  PrismTech  –    All  Rights  Reserved. mit mit ☐ The Time Based Filter allows to control the throughput at which Latency = T1+T2+T3 data is received by a data reader OpenSplice DDS DataWriter T3 DataReader ☐ Samples produced more often T2 than the minimum inter-arrival time are not delivered to the data reader mit mit mit = minimum inter-arrival time produced sample delivered sample discarded sample
  • 42.
    QoS Provider ☐ The new C++ and Java APIs introduce the concept of a QoS Copyright  2011,  PrismTech  –    All  Rights  Reserved. Provider ☐ This class allows to externally define policies and decouples the mechanism used to define and access policy definition with policy OpenSplice DDS creation            //  QosProvider...            QosProvider  qos_provider(                        "http://www.opensplice.org/demo/config/qos.xml",                        "ishapes-­‐profile");            DataReader<ShapeType>  dr(sub,  topic,  qos_provider.datareader_qos());
  • 43.
    QoS and DataModeling OpenSplice DDS Patterns
  • 44.
    Soft State ☐ In distributed systems you often need to model soft-state -- a state Copyright  2011,  PrismTech  –    All  Rights  Reserved. that is periodically updated ☐ Examples are the reading of a sensor (e.g. Temperature Sensor), the position of a vehicle, etc. OpenSplice DDS ☐ The QoS combination to model Soft-State is the following: Reliability            =>    BestEffort Durability              =>    Volatile   History                    =>    KeepLast(n)  [with  n  =  1  in  most  of  the  cases] Deadline                  =>    updatePeriod LatencyBudget        =>    updatePeriod/3  [rule  of  thumb] DestinationOrder  =>    SourceTimestamp  [if  multiple  writers  per  instance]
  • 45.
    Hard State ☐ In distributed systems you often need to model hard-state -- a state Copyright  2011,  PrismTech  –    All  Rights  Reserved. that is sporadically updated and that often has temporal persistence requirements ☐ Examples are system configuration, a price estimate, etc. OpenSplice DDS ☐ The QoS combination to model Hard-State is the following: Reliability            =>    Reliable Durability              =>    Transient  |  Persistent   History                    =>    KeepLast(n)  [with  n  =  1  in  most  of  the  cases] DestinationOrder  =>    SourceTimestamp  [if  multiple  writers  per  instance]
  • 46.
    Events ☐ In distributed systems you often need to model events -- the occurrence of something noteworthy for our system Copyright  2011,  PrismTech  –    All  Rights  Reserved. ☐ Examples are a collision alert, the temperature beyond a given threshold, etc. OpenSplice DDS ☐ The QoS combination to model Events is the following: Reliability            =>    Reliable Durability              =>    any                [depends  on  system  requirements]   History                    =>    KeepAll  [on  both  DataWriter  and  DataReader!] DestinationOrder  =>    SourceTimestamp
  • 47.
    Streams Copyright  2011,  PrismTech  –    All  Rights  Reserved. ☐ At times you need to deal with high volumes of frequently changing soft-state ☐ You may have from several hundreds of thousands to several OpenSplice DDS millions of data readings that need to be distributed in your system... Where each reading is usually from few tends to few hundreds of bytes ☐ OpenSplice provide a special abstraction to deal with this situation called Streams
  • 48.
    Streams struct SCADASensor { long sid; float value; }; #pragma stream SCADASensor ☐ OpenSplice Streams Copyright  2011,  PrismTech  –    All  Rights  Reserved. transparently perform batching and un- High Frequency High Frequency batching of data based Samples Samples on samples count or OpenSplice DDS time StreamDataWriter StreamDataReader ☐ OpenSplice Streams Batching Un-Batching also provide explicit Temporal or Samples-Count flush operation to force Driven Batching the middleware to send data
  • 49.
    StreamDataWriter Copyright  2011,  PrismTech  –    All  Rights  Reserved. StreamDataWriterQos  sqos(max_samples,  max_delay); SCADASensorStreamDataWriter  sdw  =        new  SCADASensorStreamDataWriter(did,  sqos,  “ScadaSensorT”); OpenSplice DDS StreamId  sid  =  0;  //  Your  stream  Id SCADASensor  data  =  ... sdw.append(sid,  data); ... //  Explicitely  flush  the  stream sdw.flush(sid);
  • 50.
    StreamDataReader Copyright  2011,  PrismTech  –    All  Rights  Reserved. SCADASensorStreamDataReader  sdr  =        new  SCADASensorStreamDataReader(did,  “ScadaSensorT”); StreamId  sid  =  0;  //  Your  stream  Id SCADASensorSeq  data; OpenSplice DDS //  Issue  a  blocking  get sdw.get(sid,  data,  DDS::LENGTH_UNLIMITED,  DDS::DURATION_INFINITE); //  Note:   //    -­‐  get_with_filter  is  also  available  to  filter  data //    -­‐  The  Stream  Examples  are  shown  using  the  DDS  C++  2004  API   //        since  these  are  OpenSplice  specific  extensions.   //        DDS  C++  2010  counterparts  will  be  soon  available.
  • 51.
  • 52.
    LongVariable Example ☐ The “distributed” version of the following code: Copyright  2011,  PrismTech  –    All  Rights  Reserved. int  x; int  y; x  =  10; y  =  20; OpenSplice DDS Topic Type ☐ Becomes: // Create a Publisher struct LongVariable { auto lvt = Topic<LongVariable>(dp, “TLongVariable”); @Key string name; // Create DataWriters long value; auto dw = DataWriter<LongVariable>(pub, topic); }; // Write Data dw.write(LongVariable(“x”,10)); dw.write(LongVariable(“y”,20)); PS. long in IDL is a 32 bit integer
  • 53.
    Looking with theSpyglass Copyright  2011,  PrismTech  –    All  Rights  Reserved. Topic TLongValue struct LongVariable { @Key string name; long value; OpenSplice DDS dw }; Policies name value x 10 y 20
  • 54.
    Declaration vs. Assignement Copyright  2011,  PrismTech  –    All  Rights  Reserved. Assignment {   Declaration    int  x; dw.write(LongVariable(“x”,10));    x  =  10; Assignment OpenSplice DDS } Resources Reclamation ☐ Can we declare topic instances in DDS? ☐ Can we control resource reclamation?
  • 55.
    Instance Registration Copyright  2011,  PrismTech  –    All  Rights  Reserved. {   auto key = LongVariable(“x”,0) Declaration    int  x; auto handle = Declaration    x  =  10; dw.register_instance(key); Assignment OpenSplice DDS } dw.write(LongVariable(“x”,10)); Assignment Resources Reclamation ☐ Instance registration provides a way of informing the system that the given data writer will be writing the given instance ☐ This operation has an impact on instance life-cycle ☐ The write operation implicitly register the instance being written, if necessary
  • 56.
    Instance Un-registration ☐ DDS provides a way for a DataWriter to “un-register” an Copyright  2011,  PrismTech  –    All  Rights  Reserved. instance thus informing the system that he won’t be writing that specific instance any more This operation has an impact on instance life-cycle OpenSplice DDS ☐ dw.unregister_instance(handle);
  • 57.
    Instance Disposal auto key = LongVariable(“x”,0) {   Declaration auto handle = Copyright  2011,  PrismTech  –    All  Rights  Reserved. Declaration    int  x; dw.register_instance(key);    x  =  10; } Assignment dw.write(LongVariable(“x”,10)); dw.dispose_instance(handle) Assignment OpenSplice DDS Resources Reclamation Resources Reclamation ☐ Allows to control resource reclamation for a given instance. ☐ The action of disposing an instance signifies that the system is done with it...
  • 58.
    Writer Data Lifecycle The life-cycle of data on the Writer side is controlled by means of Copyright  2011,  PrismTech  –    All  Rights  Reserved. ☐ QoS policy we’ve not introduced yet, the WriterDataLifecycle ☐ This policy controls wether unregistered instances are automatically OpenSplice DDS disposed or not ☐ This is quite important since when a writer is disposed all its instances are automatically unregistered and depending on the setting of this QoS might also be disposed... Which in some cases is not what you want!
  • 59.
    Reader Data Lifecycle ☐ The lifecycle of the data-instances received by the DataReader is Copyright  2011,  PrismTech  –    All  Rights  Reserved. controlled by the ReaderDataLifecycle policy ☐ This policy allow to control two properties ☐ autopurge_nowriter_samples_delay: the maximum duration for OpenSplice DDS which the DataReader will maintain information on an instance once its state becomes NOT_ALIVE_NO_WRITERS ☐ autopurge_disposed_samples_delay: the maximum duration for which the DataReader will maintain samples for an instance once its state becomes NOT_ALIVE_DISPOSED PS. The default setting for this policy is INFINITE for both delays
  • 60.
    DDS and Functional Programming OpenSplice DDS
  • 61.
    Why Functional Programming(FP)? Some of the main reasons for the steep increase in the adoption of Functional Copyright  2011,  PrismTech  –    All  Rights  Reserved. Programming languages are: ☐ Referential Transparency (no side effects): makes it easier to write reusable code and facilitates concurrency (increasingly more important due to multi- cores) OpenSplice DDS ☐ Declarative style: makes code easier to understand (once you understand the language) ☐ Higher Order abstractions: Higher order functions, pattern matching, algebraic data types, Higher Kinds, makes it easier to express solutions in our domain ☐ Domain Specific Languages (DSL): Functional programming languages like Haskel and Scala make it easy to develop DSLs
  • 62.
    Why DDS andFP? ☐ Data Centricity and Stream Computing match very naturally with Copyright  2011,  PrismTech  –    All  Rights  Reserved. functional programming ☐ All of a sudden your system can be easily modeled as streams of data transformed by composable functions OpenSplice DDS ☐ Referential transparency makes it easily parallelizable F(x) G(y,z)
  • 63.
    struct  TempSensor  { Example      long  id;      float  temp;      float  hum; }; #pragma  keylist  TempSensor  id Compute the moving average for temperature and humidity Copyright  2011,  PrismTech  –    All  Rights  Reserved. ☐ val  tst    =  Topic[TempSensor]("TempSensorT") val  atst  =  Topic[TempSensor]("AverageTempSensorT") OpenSplice DDS val  rqos  =  DataReaderQos()  <=  History.KeepLast(windowSize) val  dr  =  DataReader[TempSensor](tst,  rqos) val  dw  =  DataWriter[TempSensor](atst) reader.reactions  +=  {    case  DataAvailable(_)  =>  {                val  window  =  dr.history.data        val  tempAvg  =  (0F  /:  window)(_  +  _.temp)  /  window.length        val  humAvg    =  (0F  /:  window)(_  +  _.hum)  /  window.length        dw  !  new  TempSensor(-­‐1,  tempAvg,  humAvg)      } }
  • 64.
  • 65.
    List Comprehension inDDS Copyright  2011,  PrismTech  –    All  Rights  Reserved. ☐ When using the SCALA API, the DDS readers expose data as LinearSeqOptimized thus making possible list comprehension to address quite a few task OpenSplice DDS ☐ Example ☐ dr read foreach (println) ☐ dr read map (transformer) ☐ ...
  • 66.
    Examples Compute the average shape and write it as a Gray Square: Copyright  2011,  PrismTech  –    All  Rights  Reserved. ☐ val data = dr history val s0 = new ShapeType(“GRAY”, 0, 0 ,0) OpenSplice DDS dw ! scaleShape((s0 /: data) (sumShape), data.size) ☐ Filter samples: (dr read) filter (_.x <= 100 && _.y <= 200)
  • 67.
    OpenSplice DDS References
  • 68.
    DDS ISO C++API 2010 Copyright  2011,  PrismTech  –    All  Rights  Reserved. ☐ github.com/kydos ☐ New C++ API OpenSplice DDS ☐ Demo applications ☐ Alpha reference implementation (simd-cxx) ☐ online docs ☐ kydos.github.com/dds-psm-cxx/
  • 69.
    OpenSplice DDS ☐ ☐ ☐ New Java API github.com/kydos Demo applications DDS Java 5 API 2010 Copyright  2011,  PrismTech  –    All  Rights  Reserved.
  • 70.
    DDS Scala API Copyright  2011,  PrismTech  –    All  Rights  Reserved. ☐ github.com/kydos ☐ Scala API for DDS Set of demo showing how OpenSplice DDS ☐ the API can be used ☐ Notice that this API can also be used for scripting DDS applications
  • 71.
    OpenSplice DDS Summing Up
  • 72.
    Concluding Remarks OpenSplice DDS provides a very powerful abstraction for building Copyright  2011,  PrismTech  –    All  Rights  Reserved. ☐ distributed applications grounded on the concept of a fully distributed global data space OpenSplice DDS ☐ Topics are used to define the types that populate the global data space while DataWriters and DataReaders are used to produce and consume values ☐ DataReaders allow very flexible data access through cache access operations
  • 73.
  • 74.
    References Copyright  2011,  PrismTech  –    All  Rights  Reserved. OpenSplice | DDS Escalier ¥ #1 OMG DDS Implementation ¥ Fastest growing JVM Language ¥ Scala API for OpenSplice DDS ¥ Open Source ¥ Open Source ¥ Open Source ¥ www.opensplice.org ¥ www.scala-lang.org ¥ github.com/kydos/escalier OpenSplice DDS ¥ Simple C++ API for DDS ¥ DDS-PSM-Java for OpenSplice DDS ¥ DDS-based Advanced Distributed ¥ Open Source ¥ Open Source Algorithms Toolkit ¥ github.com/kydos/simd-cxx ¥ github.com/kydos/simd-java ¥ Open Source ¥ github.com/kydos/dada
  • 75.
    :: Connect withUs :: ¥opensplice.com ¥forums.opensplice.org ¥@acorsaro ¥opensplice.org ¥opensplicedds@prismtech.com ¥@prismtech OpenSplice DDS ¥ crc@prismtech.com ¥sales@prismtech.com ¥youtube.com/opensplicetube ¥slideshare.net/angelo.corsaro