ATLAS

ATLAS Week: 25/Feb to 1/Mar 2002

Data Manager DesignStatus Report

http://hepunx.rl.ac.uk/atlasuk/simulation/level2/meetings/PESA270202/DM.pptDM.pdf

DM.ps

John Baines

Contents:• Motivation • Use Case• First Design :

• Components• Interfaces• RobMaper• Status

• Second Design Iteration• Summary

ATLAS Week 25/Feb to 1/Mar 2002 2

Motivation• The PESA s/w high level design includes a Data Manager.

• It’s function is to provide the same interface to data for LVL2, EF and offline

• This divides into access to :

•Raw Data

•Reconstructed objects

• Also considered as possibly part of the Data Manager Domain are :

• Access to LVL1 info (but also possibly done from top-level algorithm)

• Packing of LVL2 result and transmission to Data Collection.

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Use Case &Collaboration Diagram for a

Possible Implimentation

1) Data Manager receives request for data in region specified by Geometrical Volume Descriptor. 2) Data Manager asks RoB Mapper to convert Geometrical Volume into list of RoB IDs. 3) Data Manager checks if all/part of data already present in Event Store. 4) If not, Data Manager requests data from Rob Data Collector. 5) Data Manager stores the data returned in Event Store. 6) Data Manager selects requested data from Event Store

and returns it to requester.

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Components of the Design• Geometrical Region : describes region either :

• in purely geometrical terms (e.g. cone defined in terms of and or road about a track-helix), or• as mixture of geometrical and detector-specific info. (e.g. an cone plus a list of detector layers).

• Rob Mapper : receives GeometricalRegion and returns list of RoB Identifiers for all RoB that contain detectors lying wholly or partially inside GeometricalRegion.

• Byte Stream To Object Converter : Performs conversion of raw data received from RoS to collections of Digit Objects.

• Rob Data Collector : receives a list of RoB Identifiers and formulates the specific requests to be sent to Data Collection. The Rob Data Collector hides the details of Data Collection from the Data Manager.

• Data Preparation : Converts the raw data to the form requested, e.g. after calibration or SCT cluster-finding.

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Possible Interfaces

•Gaudi & Athena frameworks use idea that concrete classes can inherit from several interfaces.

•Separate Data Manager interface as follows:

• ITrigEventStoreSvc : Storage and retrieval of intermediate results. Similar to Athena IStoreGateSvc interface. • ITrigDetDataSvc : Retrieval of detector data, either raw or pre-processed. Differs from ITrigEventStoreSvc interface in that the detector identifier and geometrical region for data collection are specified. •ITrigLvl1DataSvc : Retrieval of LVL1 data in the form of a list of RoI.

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• GeometricalRegion base class defined with 3 derived

classes : EtaPhiCone, HelicalRoad1, and HelicalRoad2 • RobMapperSvc designed by Weidong Li Implemented for SCT and Pixels:

• RoB composed of RobElement (MUR)•Two step search for RobElements in region: • Search for first RobElement inside the geometrical Region (seed RobElement)• Use clustering-type approach to add neighbouring RobElements

• Preliminary timing measurement for mapping a SCT region defined by a pixel seed (800 MHz PIII)

• Mean time about 0.2 ms per region.

RobMapper

Design: http://hepunx.rl.ac.uk/atlasuk/simulation/level2/doc/futuresw/DataAccess/robmapping/RobMapper.html

Status: http://hepunx.rl.ac.uk/atlasuk/simulation/level2/doc/futuresw/DataAccess/robmapping/test/RobmappingStatus.html

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Unpacking and Clustering

• Produce optimized unpacking and clustering for LVL2

• Unpacking and clustering are combined to :

• Avoid creating objects (digits) that are only used as the input to the next step (clustering)

• Benefit from the fact that the SCT readout zero-suppression is effectively a clustering algorithm.

• Implement LVL2-specific Cluster Classes since we:

• want something now to allow the prototyping work to continue

• would like very small objects to minimize the time taken to create them

• want to be independent of storegate

• Weidong has almost completed the implementation for the SCT and Pixels

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Interface to DataCollection• Andre dos Anjos and Andre Bogaerts have looked at the interface between the DataManager and Data Collection

• The DataManager requests data for a list of RoB IDs.

• The data is returned as a STL vector of RoBData objects.

• These provide iterators (int8, int16, int32) over the data,

• The RoBData class hides the details of the location of the data.

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Status•TrigDataMgrSvc created in Athena-based prototype (John)

•Prototype SCT & Pixel RobMaper complete (Weidong)

•Work on combined unpacking and clustering for SCT and Pixels underway (Weidong)

•Prototype LVL2 classes for SCT and Pixels designed (Weidong)

•DataManager - DataCollection interface design proceeding (Andre + Andre)

•Aim for vertical slice up to LVL2 after Easter (Raw data, DataCollection, DataManager, SpacePointFormation, PixelScan, SiTree).

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Second Design Cycle• Discussions started with EF (Christophe, Kristo, Martine) to examine design differences with the aim of a common design

• EF design uses a layered approach c.f. the DataManager approach

• Essentially the same functionality

• Try to converge on a common design, but this work is in parallel with current effort towards June integration tests.

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EF Design

RegionSelection

Collection Container

CollectionFactory

ROB Source

Collection

Algorithm

GeometricalRegion

1.create()

2.create(GeometricRegion)

3. iterate4.GetCollection(CollID)

5.buildCollection8.store(Collection)

6.GetRob()

7.Create()

{direct navigation}

Ex: next wafer in p = +1 in HashFunc

wafer in next plane = +offset in HashFunc

All collections

or all collection in ROB

or single collection

or ….

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Summary• Good progress towards a DataManager implementation in the Athena framework.

• Consists of the following for SCT and Pixels:

• Geometrical region specification

• RobMapper

• Unpacking and Clustering

• Cluster Classes

• Good progress to define interface to Data Collection

• Soon start to look at implementation in online framework

• Aim for vertical slice for June tests

• In parallel start on the second design cycle. Try to converge on a common design for EF and LVL2