ATLAS Computing Wenjing Wu

outline Local accounts Tier3 resources Tier2 resources

Application of local account

AFS Account-1 Every user needs to apply for an AFS account from the computer center to use its computing and storage resources. AFS 用户申请流程示 意图

AFS Account-2 Fill in the application form online ： lyaction.action lyaction.action Staff/ students to contact you Department Name

AFS account-3 Use kpasswd to change your password at the first login 。 Need to change your password every 254 days, s will be sent in 30/7/2 days before the expiration respectively. If you want to associate another address to your computing services, please contact the computer center. Phone ： (office hours) ：

Login Computer center provides the following login nodes to its users, so that the users can access their allocated storage and computing resources. Load balance strategies are implemented on the login nodes 。 OSNumberHost name 1 64 位 Scientific Linux lxslc5.ihep.ac.cn 2 64 位 Scientific Linux lxslc6.ihep.ac.cn

ATLAS Tier3 ATLAS Tier3 Login/storage/computing/software

Tier3 Login nodes ATLAS dedicated login nodes – atlasui01.ihep.ac.cn(x86_64 SLC 6.5, scratch disk /tmp 900GB, 32CPU/64GB Memory, public IP) – atlasui02.ihep.ac.cn(x86_64 SLC 6.5, scratch disk /tmp 900GB, 32CPU/64GB Memory, public IP) – atlasui03.ihep.ac.cn (x86_64 SLC 5.8, scratch disk /tmp 776GB, 16CPU/32GB Memory,private IP) – atlasui04.ihep.ac.cn (x86_64 SLC 6.5, scratch disk /tmp 776GB, 16CPU/32GB Memory,private IP) – atlasui05.ihep.ac.cn (x86_64 SLC 6.5, scratch disk /tmp 776GB, 16CPU/32GB Memory,private IP) – atlasui06.ihep.ac.cn (x86_64 SLC 6.5, scratch disk /tmp 776GB, 16CPU/32GB Memory,private IP)

Restrictions on the login nodes Limits are implemented on the login nodes – Check limits on user with the command ulimit –a cpu time (seconds, -t) 2700 max user processes (-u) 200 virtual memory (kbytes, -v) max memory size (kbytes, -m) – cpu time, maximum cpu time per process – max user processes, max number of processes per user – virtual memory, max virtual memory per process – max memory size, max RAM per process

Tier3 Batch system ATLAS has 576 Cores, harnessed by the PBS batch system ATLAS uses 3 PBS queues ， atlass6q and atlasl6q share 504 Cores

Tier3 Storage Public Storage ： for public data/code/software – Lustre /publicfs/atlas (300TB) Contact to create a sub directory in /publicfs/atlas – AFS ： to install shared software /afs/ihep.ac.cn/soft/atlas/ Personal Storage ： – Lustre /workfs/atlas/afs_user_name （ 10G/50K files Per user ， RW on login nodes, readonly on computer nodes ） /scratchfs/atlas/afs_user_name （ 500G per user, valid for 2 weeks after its last modification ， RW on both computer and login nodes ） – AFS 文件系统 /afs/ihep.ac.cn/users/ （ 500MB Per user ）

Query user quota Query space usage of /publicfs ： – lfs df -h -p pubfs.napool /publicfs Query your personal quota usage: – lfs quota -u afs_user_name /workfs – lfs quota -u afs_user_name /scratchfs – lfs quota -u afs_user_name /publicfs

Tier3 Software Tier3 ATLAS Software ： /cvmfs/atlas.cern.ch/repo/sw/software （ can be accessed from both login and computer nodes ）

ATLAS Tier2 ATLAS Tier2 Login/data downloading

Tier2 preparation User Certificate （ IHEP CA ）： – – Contact person: Jiaheng Import the user certificate to your web browser by clicking on the certificate file. Join ATLAS VO – Notes ： – User certificate is valid for 1 year, users will receive an 1 month before the expiration requesting reapplication of a new user certificate. Please make sure the DN is identical to the old DN, otherwise, user needs to rejoin the ATLAS VO with the new DN. – ATLAS VO requires a resign of AUP every year ， please follow the auto sent to resign the AUP.

User Certificate Check user DN and expiration date – ~]$ cd.globus/ – openssl x509 -in usercert.pem -noout -subject - enddate – subject= /C=CN/O=HEP/OU=CC/O=IHEP/CN=wenjing wu – notAfter=Dec 6 02:39: GMT How to keep your DN. (case sensitive with your names)

Tier2 Login In order to avoid repeated login to CERN for services like SVN checkout, you can initiate a Kerberos ticket on the IHEP login nodes(atlasui01-06), and use this ticket as credential to access CERN services. – Initiate the ticket: kinit （ capital CERN.CH ） – Verify the ticket klist

Tier2 data downloading DQ2 （ use DQ2 tools to download dataset to IHEP Tier2 ） source /cvmfs/atlas.cern.ch/repo/sw/ddm/latest/setup.sh export DQ2_LOCAL_SITE_ID=BEIJING-LCG2_LOCALGROUPDISK DATRI – Subscribe datasets to local Tier2 ， efficient way to transfer large amount of datasets – DATRI URL ： m_req m_req – In Destination choose BEIJING-LCG2_LOCALGROUPDISK (it has 8TB space dedicated for Chinese ATLAS users) – One needs the /atlas/cn role to be authorized to subscribe data to BEIJING-LCG2_LOCALGROUPDISK

DATRI

RUCIO RUCIO uses a lot of CPU resources, and can increase the system load significantly, thus atlasui06 is spared for dedicated RUCIO data downloading.

References ATLAS Computing Twiki – ATLAS Computing twiki: SComputing SComputing – BEIJING_LCG2 ATLAS Site Monitoring:

FAQ - 1 （ 1 ） How do I change my address associated with the computing services ？ Send an to （ 2 ） can not login to the login nodes? Very possible that your password expires, send an to to reset the password （ 3 ） My jobs are killed on the login nodes ？ Very possible that your job over uses resources such as CPU time and memory size, use ulimit –a to check the limits on the node, and adjust the cpu time and memory usage of your job,

FAQ - 2 （ 4 ） can not write to my AFS home directory ？ The AFS user token expires after 24 hours, you can use $ tokens To check the validity of the token, and use $ klog username To regenerate your token 。 （ 5 ） I can not see the output of my jobs ？ You need to specify your job output into a universally readable and writable space, such as /scratchfs/atlas. Trying to write job outputs into /afs or /workfs/atlas will fail, as they are not writable from the computer nodes.

FAQ -3 （ 6 ） why I can not access /publicfs/atlas any more ？ Very possible your have used up your quota of either total space or file number, check your quota, or make a request to increase the quota. （ 7 ） why I can not download my user certificate ？ You need to use the same web browser which was used to request the certificate to download.

FAQ -4 （ 8 ） when run startx, authentication failed ？ $ startx xauth: error in locking authority file /afs/ihep.ac.cn/users/z/username/.Xauthority Fatal server error: PAM authentication failed, cannot start X server. Your AFS token expires, please renew the token, and delete the.Xauthority file in your AFS home directory. A relogin may be required afterwards.