1. Status of the Analysis Task Force
J.F. Grosse-Oetringhaus
ALICE Week, Bologna

2. Status of the Analysis Task Force, J.F. Grosse-Oetringhaus, CERN
Initiated by Yves Schutz in May
The analysis task force’s objective is to assure that a robust and efficient analysis framework is available
By stressing the analysis tools
on the Grid
with PROOF
Share the experience with ALICE users
Submit requirements to the Offline team
Status of the Analysis Task Force, J.F. Grosse-Oetringhaus, CERN

3. Status of the Analysis Task Force, J.F. Grosse-Oetringhaus, CERN
Members
Federico Carminati - PH/AIP
Panos Christakoglou - PH/AIP
Rafael Diaz Valdes - PH/UAI
Andrei Gheata - PH/UAT
Jan Fiete Grosse-Oetringhaus - PH/AIP
Peter Hristov - PH/AIP
Claus Jorgensen - PH/AIO
Mercedes Lopez Noriega - PH/AIP
Andreas Morsch - PH/AIP
Tapan Nayak - PH/AIP
Yves Schutz - PH/AIP
Status of the Analysis Task Force, J.F. Grosse-Oetringhaus, CERN

4. Status of the Analysis Task Force, J.F. Grosse-Oetringhaus, CERN
Outlook
Summary of 4 talks from the Offline Week
Preparation of new Analysis page in the Offline Web (Diaz, R.)
File and event level metadata - Queries to the file catalog (Christakoglou, P.)
The CERN Analysis Facility: PROOF for Day-1-Physics and Calibration (Grosse-Oetringhaus, J.)
A skeleton of analysis framework (Gheata, A.)
All found here
More information about analysis on the Grid (A. Peters)
Status of the Analysis Task Force, J.F. Grosse-Oetringhaus, CERN

5. Status of the Analysis Task Force, J.F. Grosse-Oetringhaus, CERN
Analysis web page
Linked on Offline page
Information about analysis
Dedicated pages to come
Analysis framework
The CERN Analysis Facility (CAF)
Analysis on the Grid
Mailing list:
Status of the Analysis Task Force, J.F. Grosse-Oetringhaus, CERN

6. Run and event level metadata
You want to analyse events from/with e.g.
ESD files
pp collisions
the start and stop time of the run between 19/03/2008 and 20/03/2008
a properly reconstructed vertex
a Vz value between -1 cm and 1 cm
Run (File)
level
metadata
Event
level
metadata
Status of the Analysis Task Force, J.F. Grosse-Oetringhaus, CERN

7. Run level metadata Internal note by Markus Oldenburg run comment
run type
physics, laser, pulser, pedestal, simulation
run start time
run stop time
run stop reason
Normal, beam loss, detector failure, …
magnetic field setting
FullField, ReversedField, ZeroField, HalfField
collision system
PbPb, pp, pPb, …
collision energy
trigger class
detectors present in this run
# of events in this run
run sanity
for reconstructed events
production tag
production software library version
calibration & alignment setting
for simulation
Simulation config tag
...
Internal note by Markus Oldenburg
Status of the Analysis Task Force, J.F. Grosse-Oetringhaus, CERN

8. Status of the Analysis Task Force, J.F. Grosse-Oetringhaus, CERN
The event tag system
After selecting a set of files to be analyzed, more selection criteria can be applied at the event level in order to analyze only the events that fulfil them, thus reducing the analysis time. Criteria: e.g.
Multiplicity range
Mean pt range
NChargedAbove10GeV range
...
The classes that perform this step are AliEventTagCuts and AliTagAnalysis
Status of the Analysis Task Force, J.F. Grosse-Oetringhaus, CERN

9. Status of the Analysis Task Force, J.F. Grosse-Oetringhaus, CERN
The event tag system (2)
For further information on the event tag system (structure, fields and use): =s5t2&sessionId=s5&materialId=0&confId=a056302
A note on the architecture and usage of the event tag system is almost ready and will be submitted soon (P. Christakoglou)
Status of the Analysis Task Force, J.F. Grosse-Oetringhaus, CERN

10. Status of the Analysis Task Force, J.F. Grosse-Oetringhaus, CERN
PROOF
Parallel ROOT Facility
Interactive parallel analysis on a local cluster
PROOF itself is not related to Grid (can be used in the Grid)
It is aimed that the use of PROOF is fully transparent
The same code can be run locally and in a PROOF system (certain rules have to be followed)
Status of the Analysis Task Force, J.F. Grosse-Oetringhaus, CERN

11. PROOF Schema Local PC root $ root root [0] tree->Process(“ana.C”)
ESD
$ root
root [0] tree->Process(“ana.C”)
$ root

12. PROOF Schema Local PC Remote PROOF Cluster root ESD ESD ESD $ root
node1
ESD
ana.C
ESD
node2
$ root
root [0] tree->Process(“ana.C”)
$ root
ESD
node3
ESD
node4

13. PROOF Schema Local PC Remote PROOF Cluster root proof PROOF master ESD
node1
ESD
ana.C
ESD
node2
$ root
root [0] tree->Process(“ana.C”)
$ root
root [0] tree->Process(“ana.C”)
root [1] gROOT->Proof(“remote”)
$ root
ESD
node3
ESD
node4

14. PROOF Schema Local PC Remote PROOF Cluster root proof proof proof
PROOF master
node1
ESD
ana.C
ESD
proof
node2
$ root
root [0] tree->Process(“ana.C”)
root [1] gROOT->Proof(“remote”)
$ root
root [0] tree->Process(“ana.C”)
$ root
ESD
proof
node3
ESD
proof
node4

15. PROOF Schema Local PC Remote PROOF Cluster root proof proof proof
stdout/result
root
proof
PROOF master
ana.C
node1
ESD
ana.C
ESD
proof
node2
$ root
$ root
root [0] tree->Process(“ana.C”)
root [1] gROOT->Proof(“remote”)
$ root
root [0] tree->Process(“ana.C”)
root [1] gROOT->Proof(“remote”)
root [2] chain->Process(“ana.C”)
$ root
root [0] tree->Process(“ana.C”)
ESD
proof
node3
ESD
proof
node4

16. CERN Analysis Facility
The CERN Analysis Facility (CAF) will run PROOF for ALICE
Prompt analysis of pp data
Pilot analysis of PbPb data
Calibration & Alignment
Available to the whole collaboration but the number of users will be limited for efficiency reasons
Design goals
500 CPUs
100 TB of selected data locally available
Status of the Analysis Task Force, J.F. Grosse-Oetringhaus, CERN

17. CAF Schema ... Tier-1 data export Tape storage Experiment Disk Buffer
Sub set (moderated)
CAF computing cluster
Proof
node
local
disk
Proof
node
local
disk
Proof
node
local
disk
...
Proof
node
local
disk
Proof
node
local
disk
Proof
node
local
disk

18. Status of the Analysis Task Force, J.F. Grosse-Oetringhaus, CERN
Analysis Framework
Which constraints on the analysis are there?
Big events
Maximize the profit from having one event in memory
Parallelize an analysis task for subsets of events (PROOF)
If possible, serialize current event for several analysis chains
Complex analysis chains
Split a complex analysis into smaller modules
Reuse functionality provided by modules, create a pool of useful/tested/agreed ones
Assembly a big analysis from smaller independent pieces
Easily locate/debug possible problems
Something that every user wants
Simple to use and robust
Status of the Analysis Task Force, J.F. Grosse-Oetringhaus, CERN

19. Status of the Analysis Task Force, J.F. Grosse-Oetringhaus, CERN
Prototype
A data-driven model controlled by a top-level TSelector mechanism
AliAnalysisTask – a basic task depending only on input data
AliAnalysisDataSlot – representing a slot where data of a defined type may be connected to a task (A task can define several input/output slots)
AliAnalysisDataContainer – a data placeholder
Top level containers publishing initial input data for several client tasks
Result containers are connected to the output slot of a producer task and also to several client tasks
AliAnalysisManager – a selector talking to a list of top-level tasks
Task execution serialized event by event (TSelector)
The analysis developer will not have to take care of internal mechanisms of TSelector/TTask or implementation details of this framework
Status of the Analysis Task Force, J.F. Grosse-Oetringhaus, CERN

20. The analysis tasks and data containers
Status of the Analysis Task Force, J.F. Grosse-Oetringhaus, CERN

21. Status of the Analysis Task Force, J.F. Grosse-Oetringhaus, CERN
Analysis manager
Allows definition of the set of tasks and the data containers to be used
Provides methods for connecting tasks to containers to create an analysis tree
Deriving from TSelector
Allows initializing/connecting input data to top level containers via Init(), Begin() methods
Executes the top level tasks during Process()
Assemblies the output during Terminate()
Status of the Analysis Task Force, J.F. Grosse-Oetringhaus, CERN

22. Status of the Analysis Task Force, J.F. Grosse-Oetringhaus, CERN
Summary
Analysis Task Force exists to make sure that all needed tools for analysis will be in place. We have to try, test, stress the tools now  Join!
Analysis web page for all relevant information
Run & Event tags for selection of files on the Grid  Try it when you use events from PDC06!
The CERN Analysis Facility is being set up, a PROOF cluster for analysis  Try it when you analyze PDC06 events!
A prototype of the analysis framework is nearly ready  Try it!
Status of the Analysis Task Force, J.F. Grosse-Oetringhaus, CERN