NORDUGRID NORDUGRID-MANUAL-20 1/2/2019 ARC Computing Element System Administrator Guide F. Paganelli, Zs. Nagy, O. Smirnova, and various contributions from all ARC developers Contents 1 Overview 9 1.1 The grid . .9 1.2 The ARC services . .9 1.3 The functionality of the ARC Computing Element . 10 1.4 The A-REX, the execution service . 11 1.4.1 The pre-web service interfaces . 11 1.4.2 The web service interfaces . 12 1.5 Security on the Grid . 12 1.6 Handling jobs . 13 1.6.1 A sample job processing flow . 13 1.7 Application software in ARC: The RunTime Environments . 15 1.8 The local information . 17 1.8.1 Overview of ARC LDAP Infosys schemas . 17 1.9 LRMS, Queues and execution targets . 18 2 Requirements 19 2.1 Software Requirements . 19 2.2 Hardware Requirements . 19 2.3 Certificates . 20 3 Installation 21 3.1 Installation for commom GNU/Linux Distributions . 21 3.1.1 Setting up the repositories . 21 3.1.2 Performing the installation . 21 3.2 Installation for other systems and distributions . 23 3.3 Installation of certificates . 23 3.3.1 Installing host certificates . 23 3.3.2 Installing custom CA certificates . 24 3.3.3 Authentication Policy . 24 3.3.4 Revocation lists . 24 3.3.5 Authorization policy . 24 3 4 CONTENTS 4 Configuration 25 4.1 Preparing the system . 25 4.1.1 Users and groups . 25 4.1.2 Disk, partitioning, directories . 25 4.1.3 Permissions . 27 4.1.4 Networking . 27 4.1.5 Security considerations . 28 4.2 Configuration file formats . 29 4.2.1 Structure of the arc.conf configuration file . 29 4.2.2 Description of configuration items . 30 4.3 Setting up a basic CE . 31 4.3.1 Creating the arc.conf file . 31 4.3.2 The [common] section . 32 4.3.3 The [grid-manager] section: setting up the A-REX and the arched . 33 4.3.4 The [gridftpd] section: the job submission interface . 33 4.3.5 The [infosys] section: the local information system . 34 4.3.5.1 The [cluster] section: information about the host machine . 34 4.3.5.2 The [queue/fork] section: configuring the fork queue . 35 4.3.6 A basic CE is configured. What's next? . 35 4.4 Production CE setup . 36 4.4.1 Access control: users, groups, VOs . 36 4.4.1.1 [vo] configuration commands . 37 4.4.1.2 Automatic update of the mappings . 37 4.4.1.3 [group] configuration commands . 38 4.4.2 Connecting to the LRMS . 38 4.4.2.1 PBS . 39 4.4.2.2 Condor . 40 4.4.2.3 LoadLeveler . 41 4.4.2.4 Fork . 41 4.4.2.5 LSF . 42 4.4.2.6 SGE . 42 4.4.2.7 SLURM . 43 4.4.2.8 BOINC . 44 4.4.3 Enabling the cache . 44 4.4.3.1 The Cache Service . 45 4.4.3.2 Exposing the Cache . 46 4.4.3.3 The ARC Cache Index (ACIX) . 46 4.4.4 Configuring Data Staging . 47 4.4.5 Registering to an ARC EGIIS . 48 4.4.6 ARC CE to gLite Site and Top BDII integration . 50 4.4.7 Accounting with JURA . 50 CONTENTS 5 4.4.8 Monitoring the ARC CE: Nagios probes . 52 4.5 Enhancing CE capabilities . 53 4.5.1 Enabling or disabling LDAP schemas . 53 4.5.1.1 Applying changes . 54 4.5.2 Runtime Environments . 54 4.5.3 Enabling the Web Services interface . 55 4.5.4 Virtual Organization Membership Service (VOMS) . 55 4.5.4.1 Configuring trusted VOMS AC issuers . 57 4.5.4.2 Configuring VOMS AC signing servers to contact . 58 4.5.4.3 Configuring ARC to use VOMS extensions . 58 4.5.5 Dynamic vs static mapping . 59 4.5.5.1 Static mapping . 59 4.5.5.2 Dynamic mapping . 59 4.5.6 Using Argus authorization service . 60 4.5.7 Using LCAS/LCMAPS . 61 4.5.7.1 Enabling LCAS/LCMAPS . 61 4.5.7.2 LCAS/LCMAPS policy configuration . 62 4.5.7.3 Example LCAS configuration . 65 4.5.7.4 Example LCMAPS configuration . 65 4.5.8 Enabling the Arex ganglia implementation . 66 5 Operations 69 5.1 Starting and stopping CE services . 69 5.1.1 Overview . 69 5.1.2 Validating CE setup . 69 5.1.3 Starting the CE . 70 5.1.4 Stopping the CE . 70 5.1.5 Verifying the status of a service . 71 5.2 Testing a configuration . 72 5.2.1 Testing the information system . ..