1. Alice DC Status
P. Cerello
March 19th, 2004

2. Summary Status of AliRoot Status of AliEn Physics Data Challenge
Conclusions
19 Mar 2004

3. AliEn AliRoot layout ROOT G3 G4 FLUKA AliRoot Virtual MC EVGEN STEER
ISAJET
AliRoot
Virtual MC
AliReconstruction
HIJING
AliSimulation
EVGEN
MEVSIM
HBTAN
STEER
PYTHIA6
PDF
PMD
EMCAL
TRD
ITS
PHOS
TOF
ZDC
RICH
HBTP
ESD
AliAnalysis
STRUCT
CRT
START
FMD
MUON
TPC
RALICE
ROOT
19 Mar 2004

4. AliRoot Current status
Major changes in the last year
New multi-file I/O finally in full production
New coordinate system (and we survived!)
New reconstruction and simulations “drivers”
First attempt at the ESD and analysis framework
Improvements in reconstruction and simulation
Clearly the system works well, however many changes to come
ESD: the philosophy is still evolving
Introduction of FLUKA and new geometrical modeller
Development of the analysis framework
Raw data for all the detectors
Introduction of the condition database infrastructure
19 Mar 2004

5. Software Development Process
ALICE opted for a light core CERN offline team…
Concentrate on framework, software distribution and maintenance
…plus some people from the collaboration
GRID coordination (Torino), World Computing Model (Nantes), Detector Construction Database (Warsaw), Web and VMC (La Habana)
Close integration with physics!
The ALICE Physics Coordinator is also a member of the offline team
A development cycle adapted to ALICE
Developers work on the most important feature at any moment
A stable production version exists
Collective ownership of the code
Flexible release cycle and simple packaging and installation
Micro-cycles happen continuously, macro-cycles 2-3 times per year
Discussed & implemented at Off-line meetings and Code Reviews
19 Mar 2004

6. The ALICE Approach (AliEn)
Standards are now emerging for the basic building blocks of a GRID
There are millions lines of code in the OS domain dealing with these issues
Why not using these to build the minimal GRID that does the job?
Fast development of a prototype, no problem in exploring new roads, restarting from scratch etc etc
Hundreds of users and developers
Immediate adoption of emerging standards
An example, AliEn by ALICE (5% of code developed, 95% imported)
(…)
DBI
DBD
RDBMS
(MySQL)
LDAP
Commands
Packages
V.O.
&
Perl Core
Perl Modules
Libraries
External
File & Metadata Catalogue
SOAP/XML CE SE
Logger
Database
Proxy
Authentication RB
User Interface
ADBI
Config
Mgr
Package
Web
Portal
User Application
API (C/C++/perl)
CLI
GUI
AliEn Core Components & services
Interfaces
External software
Low level
High level FS
19 Mar 2004

7. Performance, Scalability, Standards
AliEn Timeline
Start
First production (distributed simulation)
Physics Performance Report (mixing & reconstruction)
10% Data Challenge (analysis)
Functionality +
Simulation
Interoperability +
Reconstruction
Performance, Scalability, Standards +
Analysis
19 Mar 2004

8. AliEn + ROOT (A) ? Results: 19 Mar 2004 provides: Analysis Macro
Input Files
Query for Input Data
new TAliEnAnalysis Object
USER
produces
List of Input Data + Locations
Job Splitting
Job Submission
IO Object 1
for Site A
IO Object 2
for Site A
IO Object 1
for Site BI
IO Object 1
for Site C
Job Object 1
for Site A
Job Object 2
for Site A
Job Object 1
for Site B
Job Object 1
for Site C
Execution
Histogram Merging
Tree Chaining
19 Mar 2004
Results:

9. PROOF of AliEn (B)
PROOF uses AliEn Grid File Catalogue and Data Management to map LFN’s to a chain of PFN’s and Workload Management to detect which nodes in a cluster can be used in a parallel session
Nice! Now I can finally analyze my datasets on the Grid and produce a histogram. And it is fast too!
The PROOF system allows:
parallel analysis of objects in a set of files
parallel execution of scripts on clusters of heterogeneous machines
19 Mar 2004

10. ALICE Physic Data Challenges
Period
(milestone)
Fraction of the
final capacity (%)
Physics Objective
06/01-12/01 1%
pp studies, reconstruction of TPC and ITS
06/02-12/02 5%
First test of the complete chain from simulation to reconstruction for the PPR
Simple analysis tools
Digits in ROOT format
01/04-06/04
10%
Complete chain used for trigger studies
Prototype of the analysis tools
Comparison with parameterised MonteCarlo
Simulated raw data
01/06-06/06
20%
Test of the final system for reconstruction and analysis
19 Mar 2004

11. PDC 3 schema Production of RAW Shipment of RAW to CERN
AliEn job control
Data transfer
Production of RAW
Shipment of RAW to CERN
Reconstruction of RAW in all T1’s
CERN
Analysis
Tier2
Tier1
Tier1
Tier2
19 Mar 2004

12. Merging
Signal-free event
Mixed signal
19 Mar 2004

13. AliEn, Genius & EDG/LCG seen by ALICE
User submits jobs
Server
Alien CE
LCG UI
Alien CEs/SEs
LCG RB
LCG PFN
LCG CEs/SEs
Catalog
Catalog
LCG LFN
LCG PFN = AliEn LFN
19 Mar 2004

14. AliEn – EDG Interface
Mar, 11th, 2003: first AliRoot job, driven by AliEn, run on EDG
Server
Job submission
Interface Site
AliEn CE
EDG UI
AliEn SE
EDG RB
EDG Site
EDG CE WN
AliEn
EDG SE
PFN
Status
report
Replica Catalogue
Data Registration
LFN
Data Catalogue
LFN=PFN
19 Mar 2004

15. ALICE PDC-3 & LCG
All the production will be started via AliEn, the analysis will be done via Root/Proof/AliEn
LCG-2 will be one CE element of AliEn, which will integrate seamlessly LCG and non LCG resources
If LCG-2 works well, it will suck a large amount of jobs, and it will be used heavily
If LCG-2 does not work well, AliEn will privilege other resources, and it will be less used
In all cases we will use LCG-2 as much as possible
We will not need to take any decision: the performance of the system will decide for us
The figure of merit will be
19 Mar 2004

16. AliEn & LCG: Data Challenge
CE/SE
A User submits jobs
Alien
CE/SE
Submission
Alien
CE/SE
Server
LCG
CE/SE
Alien CE
LCG UI
Catalog
LCG
CE/SE
LCG RB
Catalog
LCG
CE/SE
19 Mar 2004

17. AliEn – LCG Interface
Remote AliEn and AliRoot installation OK on all LCG-2 sites
Job management interface works with no real problem
No reliable SE available on the LCG production infrastructure
generated data is always moved to CERN CASTOR as soon as the job finishes, using AliEn tools (AIOd).
An interface to LCG storage is anyhow available, and it will be tested as soon as LCG provides storage support on the EIS testbed.
19 Mar 2004

18. Software Installation on LCG
Via LCG jobs
$VO_ALICE_SW_DIR/root/v /…
geant3/v0-6/…
aliroot/v4-01-Rev-00/…
alien/…
AliEn/…
LCG site
installAlice.sh
installAlice.jdl
LCG site
LCG-UI
LCG site
installAliEn.sh
LCG site
installAliEn.jdl
LCG site
19 Mar 2004

19. First Event Round on LCG
Submitted OK
Aborted by LCG
“Zombi”
Aborted by AliEn
Still runinng
Friday batch
480
157 5
201
117
Sunday batch
250
149 1
100
OK: as reported by AliEn. Output transfered to CERN CASTOR and registered on AliEn Data Catalogue
Aborted by LCG: reported as “Aborted” by LB.
Zombi: lost contact between AliEn and the job. All due to server and gateway restarts, many probably finished correctly on LCG.
Aborted by AliEn: failed. Many due to server and gateway problems since then fixed.
Still running: As reported by AliEn on Sunday, Feb, 29th, 5 p.m.
19 Mar 2004

20. Short history Jan 03: Requirements for ALICE PDC04 presented to PEB
End Dec 03: Announcement of LCG-2 by mid February 2004
Beg Jan 04: Decision to delay PDC04 by one month waiting for LCG-2
End Jan 04: LCG announces that there will be no SE in LCG-2
Beg Feb 04: The WAN resources allocated by LCG for data storage are insufficient/inadequate
Mid Feb 04: Development of an ALICE solution, developed in haste and working against all odds!
End Feb 04: IT has also come up with a solution responding to a CMS requirement
End Feb 04: Production started, new sites being added
Confusing that during all this time LCG-2 has been declared “ready for ALICE” on a day-by-day basis!
Beg Mar 04: castor database has to be reinstalled (running on Linux 6.2!)
Beg Mar 04: castor servers have to be reinstalled for security
Beg Mar 04: LCG RB works differently on the different centres. CNAF has to be switched on and off by hand, otherwise it “swallows” all the jobs!
Beg Mar 04: we are getting now close to 10 TB, 30 were promised by LCG on 1/1/04
Mid Mar 04: Files on the IT-provided pool are erased before being copied on tape(!)
18 Mar 04: restart production & insert Grid.it
19 Mar 2004

21. Shapshot on Mar, 16th
file:///C:/Documents%20and%20Settings/Piergiorgio%20Cerello/My%20Documents/Alice/AlienControls.htm
19 Mar 2004

22. Data Challenge Statistics
First round, closed on Mar 16th
19 Mar 2004

23. Data Challenge Statistics
First round, closed on Mar 16th
19 Mar 2004

24. Data Challenge Statistics
First round, closed on Mar 16th
19 Mar 2004

25. DC Monitoring: http://alien.cern.ch
Monalisa:
19 Mar 2004

26. Shapshot on Mar, 18th
file:///C:/Documents%20and%20Settings/Piergiorgio%20Cerello/My%20Documents/Alice/AlienControls2.htm
19 Mar 2004

27. Data Challenge Statistics
First+Second round, started on Mar 18th : jobs
19 Mar 2004

28. Data Challenge Statistics
First+Second round, started on Mar 18th : +1051, + 680
19 Mar 2004

29. Data Challenge Statistics
First+Second round, started on Mar 18th : +592, +476
19 Mar 2004

30. Present Status AliEn native sites LCG-2 sites Grid.it sites
CERN, CNAF, Cyfronet, Catania, FZK, JINR, LBL, Lyon, OSC, Prague, Torino
LCG-2 sites
CERN, CNAF, RAL ok (up to 400 concurrent jobs)
FZK: problems with installation, solved as of mar, 18th
NIKHEF: old version of aliroot in $PATH – solved as of mar,18th
TAIWAN: intermittent problems (network?)
Fermilab: “not an Alice site”
Grid.it sites
Installation (aliroot & AliEn) ok everywhere but Bo
In production as of mar, 18th
Ba, Ct, Fe, LNL, Pd, To ok
Bo-INGV, Pi, not seen by RB
Bo, Rm: minor installation problems
Mar, 19th, 00:30 – Ba 1, Ct 7, Fe 7, LNL 97, Pd 70, To 17 = 199 running jobs
19 Mar 2004

31. Double access @ CNAF WN WN WN WN WN Alien/CNAF CE/SE Alien CE LCG UI
A User submits jobs
Alien/CNAF
CE/SE WN
Submission
Server WN
Alien CE
LCG UI
LCG/CNAF
CE/SE WN
LCG RB WN
19 Mar 2004

32. Remarks
First GRID production with fully transparent common access to different middlewares (AliEn & LCG)
Relevant improvement in the LCG stability (450/12 hours wrt. 450/2 months)
AliEn – LCG load is about 50-50
Optimal situation: wrt any other choice (AliEn only or LCG only) the availability of resources is doubled
There is room for improvement (on both sides)
but
The Data Challenge started well, altough it is just at the beginning
We hope in the continued support from LCG
And centres should provide us with the promised resources
AliEn already provides functionality for distributed analysis
LCG/ARDA will improve it
19 Mar 2004

33. Conclusions
ALICE has solutions that are evolving into a solid computing infrastructure
Major decisions have been taken and users have adopted them
Collaboration between physicists and computer scientists is excellent
The tight integration with ROOT allows a fast prototyping and development cycle
AliEn goes a long way toward providing a GRID solution adapted to HEP needs
It allowed us to do large productions with very few people “in charge”
Many ALICE-developed solutions have a high potential to be adopted by other experiments and indeed are becoming “common solutions”
19 Mar 2004

34. 19 Mar 2004

35. AliEn 19 Mar 2004 DB Proxy User Interface Factory Auditing DBD/RDBMS
Registry/Lookup/Config
V.O. directory
Authentication
Storage Element
Gatekeeper
Job Manager
Transfer Manager
File Transfer 1 1
1. lookup
Grid Monitoring CE
1..n
3. register
2. authenticate
API
1..n 1
4. bind 1
0..n
Process Monitor
Transfer Broker
Job Broker
Job Optimizer
Transfer Optimizer
Catalogue Optimiser
User Interface
0..n 1
0..n 1
1..n
0..n 1 1
0..n 1 1 1 1
0..n
19 Mar 2004

36. ARDA in a nutshell ARDA RTAG
“Long they laboured in the regions of Eä, which are vast beyond the thought of Elves and Men, until in the time appointed was made Arda...” - J.R.R Tolkien, Valaquenta
ARDA in a nutshell
ARDA RTAG
Found AliEn “the most complete system among all considered” in Sep ‘03
Suggested a “fast prototype” in 6 months
Six months went to calm the turmoil spurred by this report!
ARDA is now started as suggested by the report
At least so we hope!
ARDA, if successful, will form the basis for the EGEE MW
19 Mar 2004

37. AliEn++ (ARDA)
19 Mar 2004

38. ROOT, ALICE & LCG LCG has brought support for ROOT and FLUKA
We will continue to develop our system
Providing basic technology,e.g. VMC and geometrical modeller
… and we will try to collaborate with LCG wherever possible
Possible convergence in the simulation area, collaboration on simple benchmarks
We have proposed to base LCG on ROOT and AliEn
LCG established a client-provider relationship with ROOT, which is rapidly evolving
Is now adopting AliEn via ARDA/EGEE
LCG decided to develop alternatives for some ROOT elements or hide them with interfaces
We expressed our worries
No time to develop and deploy a new system
Duplication and dispersion of efforts
Divergence with the rest of HEP
We will keep looking for opportunities to collaborate
19 Mar 2004