In this issue of ALICE Matters Armenuhi Abramyan and Narine Manukyan, trainee programmers at the A. I. Alikhanyan National Scientific Laboratory (ANSL, the former Yerevan Physics Institute), and Bachelor students at the State Engineering University of Armenia (SEUA), talk about their work at ALICE.
Armenuhi (left) and Narine (right)
How long have you worked at ALICE?
Armenuhi: I am a member of the ALICE team of A.I.Alikhanyan National Scientific Laboratory (ANSL) since May of 2009. I work for the ALICE Offline team. My first visit to CERN was in 2010. At CERN I have learnt a lot of the ALICE Offline software (AliEn, ROOT and AliRoot). I have submitted my first job to the Grid Environment of ALICE (AliEn); before that I had never used the Grid. I have participated in the ALICE Offline shifts and this helped me to get knowledge on the ALICE Online-Offline computing model. Then following the suggestion of Latchezar Betev, I started to develop UML (Unified Modeling Language) diagrams describing the AliEn functionality. UML is a standard modeling language that gives the possibility to represent a system architecture and functioning dynamics on the basis of different types of diagrams. This work I continued in Yerevan, and I have created and uploaded to the AliEn documentation web pages for developers, UML Sequence diagrams describing the AliEn Job execution process and the PackMan service. PackMan is a service that is responsible for the installation, configuration, update and removal of software packages required for the execution of AliEn jobs. This year at the July ALICE Offline week I presented a talk about this work.
Narine: I’m member of the ALICE team of ANSL since January of 2010. I’m working in the ALICE offline team. Following the suggestion of our team leader, Ara Grigoryan, I have installed the ALICE/WLCG (Worldwide LHC Computing Grid) site on the ANSL cluster of ArmGrid (Armenian National Grid infrastructure). That was one of the important contributions of our ALICE Armenian team to the ALICE collaboration. I can say that it was really great experience, since the Grid infrastructure was a whole new environment for me. The ALICE site of ANSL started its operation in December of 2010.
My first visit to CERN was in July-August of this year. During the ALICE Offline week I presented my work on the WLCG/ALICE site installation on the ANSL cluster.
I have participated in the ALICE DAQ+CTP shifts; the preparation for the shifts gave me the chance to closely study the ALICE online systems (DAQ, CTP, DCS, HLT) and understand the structure of the ALICE experiment.
Armenuhi: And I have participated in the ALICE DCS shifts. I liked these shifts, because the DCS is a very interesting system; next year I am planning to participate in the DAQ shifts, in order to learn more about the ALICE online system.
Narine: This year Armenuhi and I have been working on the update of the PackMan service, concerning especially the removal of the bottleneck caused by several commands of this service (such as define, list, listInstalled, install, undefine).
Armenuhi: I have modified the source code of the PackMan service, by creating a new Perl module that provides the functioning of the PackMan "list" command without connection to the AliEn PackMan and PackManMaster central modules. This command returns the list of packages defined in the AliEn “File Catalogue” database.
Narine: I have modified the source code of the PackMan “listInstalled" command (it gets the list of all installed packages on the site) to provide its execution without connection to Service::PackMan and PackMan::Local central modules of AliEn. This decreases the number of connections between these modules and thus speeds up the execution of the command.
How do you like CERN?
Armenuhi: I liked CERN from the first working day; the people at CERN are very friendly and in my opinion, they are always ready to help and share their knowledge.
Narine: My first visit to CERN was an incredible event in my life. I really liked CERN. People and environment are so nice at CERN.
What do you do at ALICE presently?
Narine: Now, in ANSL we are continuing the work on the speeding up of the execution of the other commands of the AliEn PackMan module.
Armenuhi: All this is extremely interesting for us and we have decided that our future Bachelor, Master Study and PhD theses will be dedicated to the subjects related to the investigations and developments carried out in ALICE.