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SSL connection option

vLHCathome news - Thu, 09/22/2016 - 11:30
For those with BOINC clients above version 7.2, there is now an option to connect with SSL on the URL:

https://lhcathome.cern.ch/vLHCathome/

This server runs a web-front end and scheduler for this project. To use it, please detach fron the project, and re-attach using the new HTTPS URL.

The other project daemons still run on the same server as before. The old server and URL will remain in place until further notice.

So far our tests of this distributed server setup works fine, and we would appreciate feedback in case of problems.
Categories: vLHCathome news

Changes to the multicore app configuration

Atlas news - Tue, 09/13/2016 - 10:09
After analysis of results from the multicore app (see this thread) we have made the following changes

- Minimum VirtualBox version required is 5.0.0
- Maximum cores reduced from 12 to 8 (this can be overridden in app_config.xml but we have seen severe performance issues above 8 cores)
- Enforced that hardware acceleration is enabled on the host. This should stop the -148 ERR_EXEC errors because WU will not be sent to these hosts.

Please continue to provide your feedback on changes we make.
Categories: Atlas news

Removing the restriction on running work units

vLHCathome news - Tue, 09/06/2016 - 15:13
After experimenting with a number of options, a solution has been found to provide a default limit on the number running work units per host for new volunteers which can be disabled by those who are more experienced.

Once implemented, a new setting will be available in the project preferences where the Max # jobs can be set. In order to provide this, three steps are required.

  • Update the project to support the option
  • Updated everyone's project preferences to set this value to 2 tasks
  • Remove current the project limit



This should be transparent for everyone and only those who wish to receive more tasks will get them once they have changed the value of this new setting. Work on this will start immediately and should be completed within the next few days.

Categories: vLHCathome news

Removing the restriction on running work units

vLHCathome news - Tue, 09/06/2016 - 15:13
After experimenting with a number of options, a solution has been found to provide a default limit on the number running work units per host for new volunteers which can be disabled by those who are more experienced.

Once implemented, a new setting will be available in the project preferences where the Max # jobs can be set. In order to provide this, three steps are required.

  • Update the project to support the option
  • Updated everyone's project preferences to set this value to 2 tasks
  • Remove current the project limit



This should be transparent for everyone and only those who wish to receive more tasks will get them once they have changed the value of this new setting. Work on this will start immediately and should be completed within the next few days.

Categories: vLHCathome news

Tips on how to gain better performance on the ATLAS_MCORE app

Atlas news - Tue, 09/06/2016 - 03:23
According to our test, the CPU performance (We measure the CPU performance by seconds of CPU per event. For example, the current ATLAS job running on the ATlAS_MCORE app processes 100 events, if the overall CPU time for this job is 30000 seconds, then the CPU performance is 300 seconds/event) varies to the number of cores of the vm.

In the test, we also compared the CPU performance on different Virtualbox versions.

The test result can be seen here:



Also, we conclude a result from the ATLAS job statistics based on the jobs from over 1 month period. The following result shows the average CPU performance on different number of cores. (ATLAS_MCORE supports up to 12 cores for now).



The benefit of using more cores in one vm is to save memory usage, but using big number of cores can also significantly reduce the CPU performance. Our test result also concludes this is a case in all cloud computing platforms, not just on ATLAS@home.

In order to have a good tradeoff between memory usage and CPU performance, we advise that you configure the cores to each ATLAS_MCORE job(VM) according to the overall cores and memory allocated to BOINC.For example,if your host allocates 12 cores to BOINC, by default, ATLAS_MCORE creates a vm with 12 cores with 12.1GB memory, but if the host has enough memory, you can customize the usage with the app_config.xml file, i.e. each vm uses 6 cores with 7.3GB memory, so that your host runs 2 vms, and the overall memory usage is 14.6GB.

You can limit the MultiCore-App by using the app_config.xml (This file needs to be put in your project/atlasathome.cern.ch/ directory).

Below is an example to limit each ATLAS_MCORE job to use only 6 Cores:

<app_config> <app_version> <app_name>ATLAS_MCORE</app_name> <avg_ncpus>6.000000</avg_ncpus> <plan_class>vbox_64_mt_mcore</plan_class> <cmdline>--memory_size_mb 7300</cmdline> </app_version> </app_config>

You should change these two lines to your needs:

<avg_ncpus>4.000000</avg_ncpus> <cmdline>--memory_size_mb 7300</cmdline>

Memory usage calculated by the ATLAS_MCORE app is by this formula:

memory = 2500 + (800* NumerOfCores)

so it is 7300MB for 6 cores.

We will also make some changes on the server side very soon:
1. Require a minimum version(5.0.0) of Virtualbox for the ATLAS_MCORE app.
2. Limit the ATLAS_MCORE app to use at most 8 cores.
Categories: Atlas news

Performance issues with older Virtualbox

Atlas news - Thu, 09/01/2016 - 10:46
We recently noticed that with the ATLAS Multi Core application, there is a HUGE performance difference between the old and new version virtualbox, and this is especially obvious with big multi core (Core number >4 ).


As shown in this host with 12 Cores allocated to BOINC, the older version of virtualbox (4.2.16) uses almost 3 times of CPU time compared to the newer version(5.1.2) with the same kind of jobs.More results of other hosts from our database confirms this difference. And our database also shows around 7% of hosts still use older virtualbox(version<5.00). In order to avoid wasting the CPU, we advise that you upgrade the virtualbox to the most recent ones (5.1.2 or 5.1.4).

Also, in a few days, we shall setup a requirement on the server, so that hosts with older virtualbox(version<5.0.0) no longer receives the ATLAS Multi Core jobs.
Categories: Atlas news

Moving multicore out of beta on Mon 29th August

Atlas news - Fri, 08/26/2016 - 13:27
We intend to move the multicore app out of beta on Monday the 29th August. This means that by default everyone will get both singlecore and multicore WU.

The main motivations for this are that multicore provides better CPU and memory efficiency, and we only have to manage a single stream of tasks instead of two.

If you do not want to run multicore you can disable it in your ATLAS@Home preferences in the option "Run only the selected applications"

By default the tasks will use as many cores as you have allocated to BOINC. For tuning the number of cores that the tasks will use you can create an app_config.xml file as described in this thread

At some point we plan to discontinue the singlecore app and run only multicore. The multicore app will also run on 1 core so you can still continue with ATLAS even with a single core.

Happy crunching!
The ATLAS@Home team
Categories: Atlas news

Multi-core version 1.04 with support for VirtualBox 5.1, OS X and graphics

Atlas news - Tue, 08/23/2016 - 13:27
Version 1.04 of the multicore app has been released with the following improvements:

- support for VirtualBox 5.1
- support for OS X (finally!)
- graphics (same as single core app)

Thank you for your continued support of ATLAS!
Categories: Atlas news

3 TRILLION EVENTS REACHED BY TEST4THEORY TODAY !!!

vLHCathome news - Sun, 08/21/2016 - 10:23
Congratulations and thanks to all our volunteers for helping CERN to reach the extremely impressive total of 3 Trillion events successfully simulated on our Theory project.

We have recently received warm testimonials from scientists who use and appreciate the MCPlots database which is the destination of all your work. We have posted these on our "Science" message board at:

http://lhcathome2.cern.ch/vLHCathome/forum_thread.php?id=1889&postid=21037#21037
Categories: vLHCathome news

3 TRILLION EVENTS REACHED BY TEST4THEORY TODAY !!!

vLHCathome news - Sun, 08/21/2016 - 10:23
Congratulations and thanks to all our volunteers for helping CERN to reach the extremely impressive total of 3 Trillion events successfully simulated on our Theory project.

Further announcements and testimonials from our scientists will be posted later!
Categories: vLHCathome news

Please don't upgrade to Virtual Box 5.1.2 (now supported)

vLHCathome news - Mon, 08/08/2016 - 15:22
Please don't upgrade to Virtual Box 5.1.2 as it does not seem to work for us at the moment. An issue(#1606) has been submitted to the developers.
Categories: vLHCathome news

Please don't upgrade to Virtual Box 5.1.2

vLHCathome news - Mon, 08/08/2016 - 15:22
Please don't upgrade to Virtual Box 5.1.2 as it does not seem to work for us at the moment. An issue(#1606) has been submitted to the developers.
Categories: vLHCathome news

Version 2.01 with VirtualBox 5.1 support

Atlas news - Thu, 08/04/2016 - 13:46
We have released v2.01 of ATLAS@Home (single-core) with updated vboxwrappers to support VirtualBox 5.1. This should help with the large number of STATUS_ACCESS_VIOLATION errors that happen with v2.00. Please let us know if you still have problems running with VirtualBox 5.1.
Categories: Atlas news

ATLAS@Home version 2.0 with graphics

Atlas news - Tue, 08/02/2016 - 13:29
Today we have released version 2.0 of ATLAS simulation. The main addition to this version is a graphical interface which can be launched with the "show graphics" button on the BOINC manager. The interface explains a bit more about why we do ATLAS@Home, some background information on basic particle physics, some examples of what simulation looks like and links to where you can find out more about the ATLAS experiment.

Please allow the task to run for up to a minute before launching the graphics as it requires some processes to start inside the virtual machine. The interface was created by Giulio Isacchini, a student at the University of Oslo in collaboration with the rest of the ATLAS@Home team. Please ask questions, give comments and suggestions for improvements, extra features etc on the Graphics forum. The graphics are currently only available on the single-core version, we will add it to multi-core soon.

Enjoy!

EDIT:There is a small configuration issue stopping the pages loading on Mac hosts and possibly Windows hosts too. This problem will go away in the next 3-4 hours.
Categories: Atlas news

Server Upgrade

vLHCathome news - Fri, 07/29/2016 - 14:00
The server will be upgraded Monday morning. The downtime should be no longer than a few minutes.
Categories: vLHCathome news

Server Upgrade

vLHCathome news - Fri, 07/29/2016 - 14:00
The server will be upgraded Monday morning. The downtime should be no longer than a few minutes.
Categories: vLHCathome news

LHC@Home - SixTrack Project News

Sixtrack news - Tue, 07/26/2016 - 10:37
The members of the SixTrack project from LHC@Home would like to thank all the volunteers who made their CPUs available to us! Your contribution is precious, as in our studies we need to scan a rather large parameter space in order to find the best working points for our machines, and this would be hard to do without the computing power you all offer to us!

Since 2012 we have started performing measurements with beam dedicated to probing what we call the “dynamic aperture” (DA). This is the region in phase space where particles can move without experiencing a large increase of the amplitude of their motion. For large machines like the LHC this is an essential parameter for granting beam stability and allowing long data taking at the giant LHC detectors. The measurements will be benchmarked against numerical simulations, and this is the point where you play an important role! Currently we are finalising a first simulation campaign and we are in the process of writing up the results in a final document. As a next step we are going to analyse the second half of the measured data, for which a new tracking campaign will be needed. …so, stay tuned!

Magnets are the main components of an accelerator, and non-linearities in their fields have direct impact on the beam dynamics. The studies we are carrying out with your help are focussed not only on the current operation of the LHC but also on its upgrade, i.e. the High Luminosity LHC (HL-LHC). The design of the new components of the machine is at its final steps, and it is essential to make sure that the quality of the magnetic fields of the newly built components allow to reach the highly demanding goals of the project. Two aspects are mostly relevant:
    specifications for field quality of the new magnets. The criterion to assess whether the magnets’ filed quality is acceptable is based on the computation of the DA, which should larger than a pre-defined lower bound. The various magnet classes are included in the simulations one by one and the impact on DA is evaluated and the expected field quality is varied until the acceptance criterion of the DA is met.


    dynamic aperture under various optics conditions, analysis of non-linear correction system, and optics optimisation are essential steps to determine the field quality goals for the magnet designers, as well as evaluate and optimise the beam performance.


The studies involve accelerator physicists from both CERN and SLAC.




Long story made short, the tracking simulations we perform require significant computer resources, and BOINC is very helpful in carrying out the studies. Thanks a lot for your help!
The SixTrack team




Latest papers:

R. de Maria, M. Giovannozzi, E. McIntosh (CERN), Y. Cai, Y. Nosochkov, M-H. Wang (SLAC), DYNAMIC APERTURE STUDIES FOR THE LHC HIGH LUMINOSITY LATTICE, Presented at IPAC 2015.
Y. Nosochkov, Y. Cai, M-H. Wang (SLAC), S. Fartoukh, M. Giovannozzi, R. de Maria, E. McIntosh (CERN), SPECIFICATION OF FIELD QUALITY IN THE INTERACTION REGION MAGNETS OF THE HIGH LUMINOSITY LHC BASED ON DYNAMIC APERTURE, Presented at IPAC 2014

Latest talks:

Y. Nosochkov, Dynamic Aperture and Field Quality, DOE review of LARP, FNAL, USA, July 2016
Y. Nosochkov , Field Quality and Dynamic Aperture Optimization, LARP HiLumi LHC collaboration meeting, SLAC, USA, May 2016
M. Giovannozzi, Field quality update and recent tracking results, HiLumi LHC LARP annual meeting, CERN, October 2015
Y. Nosochkov, Dynamic Aperture for the Operational Scenario Before Collision, LARP HiLumi LHC collaboration meeting, FNAL, USA, May 2015

Categories: Sixtrack news

Theory Tasks Available

vLHCathome news - Mon, 07/25/2016 - 12:22
Theory tasks are available again. The downtime was caused by a suspected NFS related problem that resulted in a bad batch of jobs. The submission code has been hardened to detect this scenario in the future. The maximum jobs in progress limit has been put back to 2 and we will consider increasing this limit in the very near future.
Categories: vLHCathome news

Theory Tasks Available

vLHCathome news - Mon, 07/25/2016 - 12:22
Theory tasks are available again. The downtime was caused by a suspected NFS related problem that resulted in a bad batch of jobs. The submission code has been hardened to detect this scenario in the future. The maximum jobs in progress limit has been put back to 2 and we will consider increasing this limit in the very near future.
Categories: vLHCathome news

CMS Application Now Available

vLHCathome news - Fri, 07/22/2016 - 22:56
As the issues with the Theory application will probably not be fixed until after the weekend, the CMS application has been made available for everyone. Due to the slightly larger memory requirements, the the number of tasks that can be run simultaneously on a host has been reduced from 2 to 1. If for whatever reason you do not wish to run the CMS application, you can update your project specific preferences to run only the applications that you select. There will be no more tasks for Theory app until the problem has been resolved.
Categories: vLHCathome news

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