1. Timm Morten Steinbeck, KIP, University Heidelberg 1/15 How to Marry the ALICE High Level Trigger DiMuon Tracking Algorithm and the ALICE High Level Trigger Data Transport Framework

2. Timm Morten Steinbeck, KIP, University Heidelberg 2/15 Trigger MT1 Trigger MT2 Raw Data ST5 Raw Data ST4 ClustFin d ST5 ClustFin d ST4 ST5 ROI Selectio n ST4 ROI Selectio n Tracker Straight lines: Normal framework (pub/sub) dataflow Curved lines: Additional messages Sequence of Steps ● Tracker receives data from trigger stations ● Calculates Region-of-Interest (ROI) in ST5 from trigger data ● Sends message to ST5-ROI- Selector ● Receives ST5 clusters from ROI ● Calculates ROI in ST4 from trigger and ST5 data ● Sends message to ST4-ROI- Selector ● Receives ST4 clusters from ROI ● Performs final tracking ● Hands tracks to decision entity Mapping of Current dHLT Algorithm to Pub/Sub Components

3. Timm Morten Steinbeck, KIP, University Heidelberg 3/15 Trigger MT1 Trigger MT2 Raw Data ST5 Raw Data ST4 ClustFin d ST5 ClustFin d ST4 ST5 ROI Selectio n ST4 ROI Selectio n Tracker Straight lines: Normal framework (pub/sub) dataflow Curved lines: Additional messages Sequence of Steps ● Tracker receives data from trigger stations Mapping of Current dHLT Algorithm to Pub/Sub Components

4. Timm Morten Steinbeck, KIP, University Heidelberg 4/15 Trigger MT1 Trigger MT2 Raw Data ST5 Raw Data ST4 ClustFin d ST5 ClustFin d ST4 ST5 ROI Selectio n ST4 ROI Selectio n Tracker Straight lines: Normal framework (pub/sub) dataflow Curved lines: Additional messages Sequence of Steps ● Tracker receives data from trigger stations ● Calculates Region-of-Interest (ROI) in ST5 from trigger data Mapping of Current dHLT Algorithm to Pub/Sub Components

5. Timm Morten Steinbeck, KIP, University Heidelberg 5/15 Trigger MT1 Trigger MT2 Raw Data ST5 Raw Data ST4 ClustFin d ST5 ClustFin d ST4 ST5 ROI Selectio n ST4 ROI Selectio n Tracker Straight lines: Normal framework (pub/sub) dataflow Curved lines: Additional messages Sequence of Steps ● Tracker receives data from trigger stations ● Calculates Region-of-Interest (ROI) in ST5 from trigger data ● Sends message to ST5-ROI- Selector Mapping of Current dHLT Algorithm to Pub/Sub Components

6. Timm Morten Steinbeck, KIP, University Heidelberg 6/15 Trigger MT1 Trigger MT2 Raw Data ST5 Raw Data ST4 ClustFin d ST5 ClustFin d ST4 ST5 ROI Selectio n ST4 ROI Selectio n Tracker Straight lines: Normal framework (pub/sub) dataflow Curved lines: Additional messages Sequence of Steps ● Tracker receives data from trigger stations ● Calculates Region-of-Interest (ROI) in ST5 from trigger data ● Sends message to ST5-ROI- Selector ● Receives ST5 clusters from ROI Mapping of Current dHLT Algorithm to Pub/Sub Components

7. Timm Morten Steinbeck, KIP, University Heidelberg 7/15 Trigger MT1 Trigger MT2 Raw Data ST5 Raw Data ST4 ClustFin d ST5 ClustFin d ST4 ST5 ROI Selectio n ST4 ROI Selectio n Tracker Straight lines: Normal framework (pub/sub) dataflow Curved lines: Additional messages Sequence of Steps ● Tracker receives data from trigger stations ● Calculates Region-of-Interest (ROI) in ST5 from trigger data ● Sends message to ST5-ROI- Selector ● Receives ST5 clusters from ROI ● Calculates ROI in ST4 from trigger and ST5 data Natural Mapping of Current dHLT Algorithm to Pub/Sub Components

8. Timm Morten Steinbeck, KIP, University Heidelberg 8/15 Trigger MT1 Trigger MT2 Raw Data ST5 Raw Data ST4 ClustFin d ST5 ClustFin d ST4 ST5 ROI Selectio n ST4 ROI Selectio n Tracker Straight lines: Normal framework (pub/sub) dataflow Curved lines: Additional messages Sequence of Steps ● Tracker receives data from trigger stations ● Calculates Region-of-Interest (ROI) in ST5 from trigger data ● Sends message to ST5-ROI- Selector ● Receives ST5 clusters from ROI ● Calculates ROI in ST4 from trigger and ST5 data ● Sends message to ST4-ROI- Selector Mapping of Current dHLT Algorithm to Pub/Sub Components

9. Timm Morten Steinbeck, KIP, University Heidelberg 9/15 Trigger MT1 Trigger MT2 Raw Data ST5 Raw Data ST4 ClustFin d ST5 ClustFin d ST4 ST5 ROI Selectio n ST4 ROI Selectio n Tracker Straight lines: Normal framework (pub/sub) dataflow Curved lines: Additional messages Sequence of Steps ● Tracker receives data from trigger stations ● Calculates Region-of-Interest (ROI) in ST5 from trigger data ● Sends message to ST5-ROI- Selector ● Receives ST5 clusters from ROI ● Calculates ROI in ST4 from trigger and ST5 data ● Sends message to ST4-ROI- Selector ● Receives ST4 clusters from ROI Mapping of Current dHLT Algorithm to Pub/Sub Components

10. Timm Morten Steinbeck, KIP, University Heidelberg 10/15 Trigger MT1 Trigger MT2 Raw Data ST5 Raw Data ST4 ClustFin d ST5 ClustFin d ST4 ST5 ROI Selectio n ST4 ROI Selectio n Tracker Straight lines: Normal framework (pub/sub) dataflow Curved lines: Additional messages Sequence of Steps ● Tracker receives data from trigger stations ● Calculates Region-of-Interest (ROI) in ST5 from trigger data ● Sends message to ST5-ROI- Selector ● Receives ST5 clusters from ROI ● Calculates ROI in ST4 from trigger and ST5 data ● Sends message to ST4-ROI- Selector ● Receives ST4 clusters from ROI ● Performs final tracking Mapping of Current dHLT Algorithm to Pub/Sub Components

11. Timm Morten Steinbeck, KIP, University Heidelberg 11/15 Trigger MT1 Trigger MT2 Raw Data ST5 Raw Data ST4 ClustFin d ST5 ClustFin d ST4 ST5 ROI Selectio n ST4 ROI Selectio n Tracker Straight lines: Normal framework (pub/sub) dataflow Curved lines: Additional messages Sequence of Steps ● Tracker receives data from trigger stations ● Calculates Region-of-Interest (ROI) in ST5 from trigger data ● Sends message to ST5-ROI- Selector ● Receives ST5 clusters from ROI ● Calculates ROI in ST4 from trigger and ST5 data ● Sends message to ST4-ROI- Selector ● Receives ST4 clusters from ROI ● Performs final tracking ● Hands tracks to decision entity Mapping of Current dHLT Algorithm to Pub/Sub Components

12. Timm Morten Steinbeck, KIP, University Heidelberg 12/15 Trigger MT1 Trigger MT2 Raw Data ST5 Raw Data ST4 ClustFin d ST5 ClustFin d ST4 ST5 ROI Selectio n ST4 ROI Selectio n Tracker Straight lines: Normal framework (pub/sub) dataflow Curved lines: Additional messages Dataflow components not shown Distribution on multiple nodes not shown Problems ● Asynchronous sending (relative to normal dataflow) not foreseen in framework ● Difficulties receiving multiple time delayed (causally linked) blocks of data for the same event in one component ● Latency delays Mapping of Current dHLT Algorithm to Pub/Sub Components

13. Timm Morten Steinbeck, KIP, University Heidelberg 13/15 Trigger MT1 Trigger MT2 ST5 ROI Selectio n Raw Data ST5 ClustFin d ST5 Tracker Raw Data ST4 ClustFin d ST4 ST4 ROI Selectio n ST4 Tracker ST5 ROI Calc ST4 ROI Calc Adapted Mapping of Current dHLT Algorithm to Components Dataflow components not shown Distribution on multiple nodes not shown Possible Solution: ● No asynchronous message sending ● All data flow is in framework ● No additional latency delay and induced idle times ● Split up of algorithm required

14. Timm Morten Steinbeck, KIP, University Heidelberg 14/15 Trigger MT1 Trigger MT2 ST5 ROI Selectio n Raw Data ST5 ClustFin d ST5 Tracker Raw Data ST4 ClustFin d ST4 Tracker ST5 ROI Calc 2/3 ST4 ROI Calc ST5 ROI Selectio n ST5 Tracker ST4 ROI Selectio n ST4 Tracker ST5 ROI Calc 1/3 ST4 ROI Calc ST5 ROI Selectio n ST5 Tracker ST4 Tracker ST5 ROI Calc 3/3 ST4 ROI Calc ST4 ROI Selectio n ST4 ROI Selectio n Dataflow components not shown Possible configuration with some load balancing Adapted Mapping of Current dHLT Algorithm to Components

15. Timm Morten Steinbeck, KIP, University Heidelberg 15/15 Raw Data ST5 ClustFin d ST5 Raw Data ST4 ClustFin d ST4 ClustFin d ST4 ClustFin d ST4 ClustFin d ST5 ClustFin d ST5 Global Tracker Global Tracker Global Tracker Trivial Mapping of Current dHLT Algorithm to Components Trigger MT1 Trigger MT2 Very monolithic approach ● No splitting up of tracking algorithm ● But, no fine grained distribution of steps ● Possibly higher latency (One event is processed fully sequentially, on one single node), requiring larger buffers in front ends