Posts by David Cameron

1) Message boards : ATLAS application : Thank you and goodbye! (Message 48019) Posted 18 Apr 2023 by David Cameron Post: Hi all, After many years at CERN I am moving on to a new job, so I will no longer be in charge of the ATLAS part of LHC@Home. It has been an great experience working on this project and I would like to thank you all for helping to produce extremely useful physics results for the ATLAS experiment. I would also like to thank the many people who give help and support on this forum even though ATLAS is one of the more challenging BOINC apps to run. Someone else will take over from me soon (the hiring process is on-going) to develop things further but in the meantime there should continue to be a steady stream of tasks available. I also hope to continue crunching for ATLAS as a "normal" volunteer. Best regards, David PS Quick advert for my new employer :) https://proton.me/
2) Message boards : ATLAS application : ATLAS vbox and native 3.01 (Message 47996) Posted 11 Apr 2023 by David Cameron Post: I can confirm we are now mostly running the Run 3 tasks. I asked for some test tasks here and got more than I thought :) These tasks are processing 500 events but each event is faster than before so the overall run time should be only a little bit longer. Also as you have noticed the console monitoring doesn’t work due to changes in the logging format. The “top” monitoring on Alt-F3 also shows a single python process instead of multiple athena.py processes.
3) Message boards : ATLAS application : ATLAS vbox and native 3.01 (Message 47977) Posted 6 Apr 2023 by David Cameron Post: In slot directory there is a init_data.xml file where you can find line: <rsc_memory_bound>6920601600.000000</rsc_memory_bound> This is for my 4 core Atlas task. Yeah, that's the old formula 3900MB + 4 * 900 MB = 6600MB = 6920601600 bytes On the development system we tested the new application with much lower memory and it was working fine even with 3000MB RAM, but here for safety it is set to 4000MB. However this setting in the xml-file is not respected on the production system. Until this is fixed you could lower the memory usage yourself by using an app_config.xml in the lhcathome.cern.ch_lhcathome-project directory. Example: <app_config> <app_version> <app_name>ATLAS</app_name> <plan_class>vbox64_mt_mcore_atlas</plan_class> <cmdline>--memory_size_mb 4000 --nthreads 4</cmdline> </app_version> </app_config> We are still running the old Run 2 tasks here so we need the memory to scale up with number of cores. Once we exclusively run Run 3 tasks we can remove the memory scaling and use a fixed value of 4GB.
4) Message boards : ATLAS application : ATLAS vbox and native 3.01 (Message 47928) Posted 28 Mar 2023 by David Cameron Post: Thanks. Just wondering why this is mentioned in (all?) log.EVNTtoHITS: maxEvents = 200 This is because each task is configured to simulate 200 events, even though there are more events than that in the input EVNT file. The EVNT file may contain 10000 events for example, so this would be split into 50 tasks of 200 events and each of those 50 tasks would download the same file. <edit> How many of those big dogs are left? </edit> I think this may be all of the remaining tasks for Run 2 simulation, which is why I would like to get the Run 3 simulation going as soon as possible.
5) Message boards : ATLAS application : ATLAS vbox and native 3.01 (Message 47926) Posted 28 Mar 2023 by David Cameron Post: The science output is the same regardless of the size of input file. The unfortunate large input files are the result of accidentally creating files with too many events instead of splitting them into smaller chunks. But they are not a waste or useless for science since the processing and output is the same.
6) Message boards : ATLAS application : ATLAS vbox and native 3.01 (Message 47916) Posted 28 Mar 2023 by David Cameron Post: Sorry, the file had the wrong permissions on the server. It should work now.
7) Message boards : ATLAS application : ATLAS vbox and native 3.01 (Message 47914) Posted 28 Mar 2023 by David Cameron Post: Hi all, We have just made release 3.01 for vbox and native apps in preparation for running updated simulation software. Until now all ATLAS tasks have been simulations of the ATLAS detector during "Run 2" of the LHC that ran from 2015 to 2018. Even 5 years later ATLAS physicists are still analysing the data from that period and require new simulations to be done. However last year "Run 3" of the LHC started and it will last until the end of 2025. Soon we will switch the ATLAS tasks here to Run 3 simulations, where many things have changed in the detector and the software used to simulate and analyse data. Version 3 of the app allows us to run both Run 2 and Run 3 simulations in the same version during the transition period, however this does make the image for vbox a bit larger (4.4GB, or 1.8GB compressed). The Linux native app is the same as before with one very minor change to set an environment variable required by the new software. The main benefit of the software used for Run 3 simulations is that it uses far less memory, less than 3GB for an 8-core task. At the moment we are not yet submitting Run 3 tasks here so everything should work exactly the same as before, but we'll start doing this soon and let you know. We have been doing some extensive testing on the LHC-dev project and there are still a couple of things to fix.
8) Message boards : ATLAS application : queue is empty (Message 47912) Posted 28 Mar 2023 by David Cameron Post: No more Atlas-Tasks ? Believe it or not, there was a problem submitting new tasks due to the change to daylight savings time in Europe on Sunday morning.
9) Message boards : ATLAS application : queue is empty (Message 47831) Posted 10 Mar 2023 by David Cameron Post: We may run out of ATLAS tasks by the end of today, but we should have some more submitted next week.
10) Message boards : ATLAS application : ATLAS vbox v2.03 (Message 47570) Posted 1 Dec 2022 by David Cameron Post: Hi all, We just released a new version of the vbox app. It contains several internal improvements to handle better various error conditions and improve performance: - New vboxwrapper version 26206 - Multiple fixes to CVMFS configuration files inside the VM to provide improved performance and reduce CVMFS-related errors - A rewritten bootstrap script which does more checks before starting tasks and provides much better error reporting in case of problems These have have all been thoroughly tested on the development server. A huge thanks to computezrmle who provided most of the fixes and improvements in this version.
11) Message boards : ATLAS application : Now that the LHC is back online, what are we "simulating" ? (Message 47364) Posted 11 Oct 2022 by David Cameron Post: There was some work a few years ago to try to produce real-time live images of the processes being simulated, but there were several technical problems that proved too difficult to solve, for example the extra resources required that Ray mentioned. People are still crunching through the data collected in the last LHC run ("Run 2", 2015-2018), and the simulations we run here are to help with those analyses. Most of the data analysis takes years to complete and so there is no urgent need yet for large-scale simulations of the current LHC run ("Run 3", 2022-2025). We hope to start running Run 3 simulations at some point next year.
12) Message boards : ATLAS application : ATLAS native v2.91 (Message 47231) Posted 6 Sep 2022 by David Cameron Post: Can you see what processes are left running once a task finishes? Unfortunately there are still some parts of ATLAS tasks hard-coded to use /var/tmp, we are working on fixing this. But I think /tmp/hsperfdata is something related to Java(?) and not coming from ATLAS tasks.
13) Message boards : ATLAS application : ATLAS native v2.91 (Message 47223) Posted 5 Sep 2022 by David Cameron Post: ATLAS native 2.91 was just released, which contains the improvements in v2.90, but with the problem with read-only tmp dirs fixed. Please let us know if you see any problems!
14) Message boards : ATLAS application : ATLAS native v2.90 (Message 47160) Posted 18 Aug 2022 by David Cameron Post: I have reverted back to v2.87. Many tasks were failing with errors creating temporary files like this: Failed to execute payload:mktemp: failed to create file via template '/tmp/asetup_XXXXXX.sh': Read-only file system which may be related to the change in the way directories are mounted in the container. I'm investigating.
15) Message boards : ATLAS application : ATLAS native v2.90 (Message 47159) Posted 18 Aug 2022 by David Cameron Post: Hi, We just released ATLAS native for Linux v2.90. This contains several improvements: - Apptainer is now used instead of Singularity to provide the container environment for the tasks. Today Apptainer is essentially the same as Singluarity but may diverge in the future, so if you rely on a local installation of Singularity it would be better to install Apptainer. However the Apptainer binary on CVMFS that is used by default should work in most cases so there should be no need to install anything locally. In case this doesn't work the tasks will fallback to use a local Singularity if it exists. - The way that the BOINC working directory is mounted into the container is changed to fix these kind of errors - The large input file used by each task is hard-linked rather than copied to the BOINC slot directory to save time and disk space Please let us know here of any issues.
16) Message boards : Number crunching : CentOS9 (Message 47153) Posted 16 Aug 2022 by David Cameron Post: Please see the following page for official CERN information on CentOS versions: https://linux.web.cern.ch/centos/ Many software packages including CVMFS are not yet ready for CentOS9 but support for CVMFS is planned soon. Is there a timewindow for using cvmfs and Boinc in CentOS9? I tried this today and ATLAS tasks worked fine out of the box. CVMFS was installed from the usual CVMFS repo and boinc-client from EPEL next.
17) Message boards : ATLAS application : Apptainer vs Singularity (Message 47152) Posted 16 Aug 2022 by David Cameron Post: We are now testing using apptainer instead of singularity on the dev project The idea is to use apptainer if it exists and works, and if it doesn't work fallback to singularity if it is installed locally. This means tasks should still work for people using a local singularity. If you would like to help out with testing please send me a private message for an invitation code to the dev project.
18) Message boards : ATLAS application : Fix for when atlas native fails with failed to create /var/lib/condor directory: mkdir /var/lib/condor: permission denied (Message 47149) Posted 15 Aug 2022 by David Cameron Post: We are testing out a fix for this on the LHC@Home dev project. It looks promising so we should be able to deploy it soon here.
19) Message boards : ATLAS application : Fix for when atlas native fails with failed to create /var/lib/condor directory: mkdir /var/lib/condor: permission denied (Message 47147) Posted 12 Aug 2022 by David Cameron Post: Downgrade to apptainer-1.0.3-1 with sudo dnf install https://github.com/apptainer/apptainer/releases/download/v1.0.3/apptainer-1.0.3-1.x86_64.rpm Can I ask in what version of apptainer you saw the errors? EDIT: I saw the github ticket https://github.com/apptainer/apptainer/issues/611 I usually see this problem when running boinc from its default location in /var/lib/boinc, and workaround it by running in a clean directory like /home/boinc.
20) Message boards : ATLAS application : ATLAS vbox v2.02 (Message 47061) Posted 3 Aug 2022 by David Cameron Post: Hi all, We have just released version 2.02 of ATLAS vbox. This comes with the same new multiattach feature that was in v2.01 but contains an updated vboxwrapper (a pre-release of v26205) which should fix some of the problems seen with v2.01. This version is available for Windows and Linux, a Mac version will come when there is an official release of the new vboxwrapper. Please let us know of any issues.

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