Development of the System remote access real

time (SRART) at JINR for monitoring and quality

assessment of data from the ATLAS LHC

experiment

(Concept and architecture of prototype SRART at

JINR)

Kotov V.M., Rusakovich N.A.

Introduction

Current status of large international collaborations in high-energy

physics has become essential that collaborators can participate in the

operations of experimental facilities from remote locations.

To address the needs for remote operations and remote

participation in the ATLAS experiment, in this report would be suggest the

problem of the construction in System remote access real time (SRART) at

JINR Dubna. The purpose of the SRART is to help scientists and

engineers JINR working on ATLAS contribute their expertise to

commissioning and operations activities at CERN.

SRART at JINR has primary functions:

•provide a physical location with access to information that is

available in control rooms and the operations centers inside Point1 at

CERN;

• communications conduit between CERN and members of the

ATLAS community located in Russia and also allows experts from the

participating institutes to be involved in the quality assessment of the

data during their processing.

In accordance with the ATLAS object model, the distributed data

quality assessment should be included in all processing levels from on-

line data taking to off-line processing by Tier 0-2.

ATLAS Remote Operations

For the start of ATLAS operations all control of the ATLAS detector, trigger and data acquisition systems as well as real-time online monitoring of data quality will be the responsibility of a shift crew working in the ATLAS CONTROL ROOM (ACR).

The remote operations centers, such as SRART at JINR, are expected to have the same kinds of monitoring as the ATLAS Point1. The ATLAS operations model is expected to evolve, and in the future more and more of the responsibilities may be transferred from the control room to the remote centers.

There are many monitoring applications that are being developed by ATLAS collaborators for use in the control room and remote site

Concept for the SRART JINR

The concept, architecture, and service composition of the system under development comply with the architecture of the TDAQ ATLAS CERN and this system is a fragment of the entire ATLAS information infrastructure.

Development of the prototype SRART at JINR is based on the

experience gained by JINR programmers, physicists, and engineers in

design of the data acquisition and processing system TDAQ ATLAS at

CERN, which allows a side range of TDAQ services to be used for the

development of the SRART at JINR and its integration in the general

distributed system for handling ATLAS LHC data.

Modern high-energy physics investigations require handling of large

amounts of information beginning with on-line data collection and

processing for input compression and further in off-line analysis using the

GRID technology.

Management of multilevel geographically distributed computation systems which underlie the information GRID infrastructure of high-energy physics experiments requires a distributed control system with a developed system for quality monitoring and assessment of the data from experiments at CERN’s LHC. Being geographically distributed, the processing system should allow remote access to the status of the detectors used in an experiment and remote data quality monitoring for all institutes participating in an experiment.

The SRART had always planned for remote data quality monitoring of ATLAS during operations and SRART was interested in providing support for training people before going to CERN, and remote participation in ATLAS studies. We saw an opportunity for JINR scientists and engineers to work together with detector experts to contribute their combined expertise to ATLAS commissioning.

Features

With construction the SRART @ JINR coming into complete operation the following features have been realized:

•CERN-style consoles with 6 workstations

•Videoconferencing installed for one console which can be expanded to two

•Webcams for remote viewing of SRART @ JINR

•Secure network for console PCs

•HD viewing of SRART @ JINR,

•Screen Snapshot Service (SSS) as like at Fermilab. [2] This work is in progress to develop the necessary tools.

SSS is an approach to provide a snapshot of a graphical

interface to remote users. A “snapshot” is defined as an image

copy of a graphical user interface at particular instance in time

such as a DAQ system buffer display of operator control

program. It is a view-only image, so there is no danger of

accidental user input. SSS was initially implemented for

desktops, but could be targeted to application GUIs.

Console

Machine hardware:•Linux box (specs equivalent to those of ACR mashine)•Dual or quad core CPU, 2.4 GHz•4 GB RAM and 2 x 500 GB HD•Gigabit Ethernet card•Displays•1 x 30” monitor @ 2560x1600•6 x 19” monitor @ 1280x1024

Software:•CERN Scientific Linux 4•NX Client•Athena•ROOT•Any monitoring software

AcknowledgementsSuccessful completion of this work would not

have been possible without the dedicated efforts of the following:

the JINR: Kazakov A., Mineev M., Aleksandrov I., Aleksandrov E., Yakovlev A., Korenkov V., Atanasov S., the TDAQ ATLAS Group at CERN: L.Mapelli, Kolos S., Lehman-Miotto G., Soloviev I., M. Caprini.

References:

1.Monitoring, S.Kolos, TDAQ Workshop, Rome, Italy, May 2009.

2.Remote Operation for LHC and CMS, Eric Gottschalk, Fermilab, RTO7, May 2007

Backup slides

21

Remote access technology

• An appropriate software for remote access still have to be chosen:– Plain X11 session is very slow on a long distance– Evaluation has been organized in the Monitoring Working Group to choose the

appropriate technology for providing viable desktop environment for remote users:• Free NX (GPL)• NoMachine commercial NX license• Sun Secure Global Desktop

– Evaluation report has been published:• https://edms.cern.ch/document/986115/1

• Conclusion:– Free NX has enough functionalities to be used in the current phase– Final decision will be taken based on the system exploitation experience by the end of

summer

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NX technology

• A layer above standard X11 Client/Server protocol:• NX is a standard which has several implementations available on the

market• Compresses X11 data• Does local caching of X11 information• For most of the applications is almost as responsive as a local X11 session• NX clients are free for non-commercial use• NX servers:

– NoMachine sells commercial version– GPL version called free NX also exists

Access policy

• Limited number of sessions is supported now:– Initially it’s planned to support 16 concurrent sessions, i.e. a session

per CPU core

• Now anybody with valid AFS account can log-in to the system• Possible approaches:

– Use per-system accounts– Use per-institute accounts– Limit a number of sessions per account