ORGANIZING AND ADMINISTERING ORGANIZING AND ADMINISTERING OF VOLUNTEER DISTRIBUTED OF VOLUNTEER DISTRIBUTED COMPUTING PROJECT SAT@HOMECOMPUTING PROJECT SAT@HOME

Oleg Zaikin, Nikolay Khrapov

Institute for System Dynamics and Control Theory SB RAS, Irkutsk, Russia

Institute for Systems Analysis RAS, Moskow, Russia

Volunteer computing project SAT@home

Started on 29 September 2011

Goal - solve hard large-scale problems that can be effectively reduced to SAT.

Applicability:•cryptography•search for combinatorial structures•bioinformatics

App versions: win_x86, linux_x86, linux_x64

General scheme

• While finding parameters of decomposition we take into account peculiarities of the original problems

• CNF encoding of the original problem is decomposed into a set of independent CNFs

Experiments

First experiment started on 21 December 2011 and finished on 7 May 2012.

10 problems of cryptanalysis of the generator A5/1 (used in GSM) were solved in using SAT approach. These problems can not be solved by Rainbow method (most popular for A5/1).

Second experiment started on 25 May 2012. The goal is to find a triple of mutual orthogonal diagonal Latin squares of order 10

MTA SZTAKI tools in SAT@home

Implemented using SZTAKI Desktop Grid package (modified BOINC) + DC-API.

SZTAKI Desktop Grid package•Easier (than standard BOINC) to deploy •No support for new versions of BOINC

DC-API•Easier (than standard BOINC API) to implement distributed applications

•No libraries for building client applications for Mac OS and 64-bit Windows

New server

TODO: Move to standard BOINC server package and API.

1.Rewrite distributed application using BOINC API

2.Deploy new BOINC server

3.Move content of site and DB from old server

4.Start new server (with same URL)

Server workability

In January 2012 due to the substantial increase of workunits DB (MySQL) switched to read-only mode.

After about 12 hours it was manually switched to standard mode.

As a result server could not cope with long list of queries (generation of new tasks, processing results).

Server status

Normal situation (18 July 2012)

In the middle of January 2012 Transitioner backlog value was 26 hours

Increasing of server performance

• Additional resources were added to VM

• Database settings were changed using mysqltuner.pl

• Logging mode of daemons was changed (I/O was a bottleneck)

• Old workunits were removed from DB TODO: move old data (1 month old) to another DB which can be huge and

slow.

• Additional validator (for checking correctness of results) was launched.

Monitoring toolkit

A toolkit for collecting statistics and monitoring of the Grid was developed.

It shows:dynamics of the project as graphs;acceleration of the grid performance;statistics about hosts and users (platforms,

countries, etc).

Google Web Toolkit, Perl and php were used.

Monitoring toolkit

SAT@home resources 18 July 2012

All hosts: 7586 •Windows: 6285 (82 %)•Linux: 1179•Mac: 74

All CPU cores 30167

Users 2349 (from 80 countries)

Active users 1062

Active means “returned a result in the last month”.

SAT@home performance

Current: 2.3 TFLOPsPeak: 4.3 TFLOPs

Last month dynamics

TODO list

New server with “pure” BOINC

Version of application for Mac OS

Connect new clusters to SAT@home

Improve algorithms for solving our SAT problems

GPU application (may be)

BOINChttp://boinc.berkeley.edu

SAT@homehttp://sat.isa.ru

Thank you for your attention!

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