An Overview of PHENIX Computing Ju Hwan Kang (Yonsei Univ.) and Jysoo Lee (KISTI) International HEP DataGrid Workshop November 8 ~ 9, 2002 Kyungpook National University, Daegu, Korea

RHIC  Configurations: Two concentric superconducting magnet rings (3.8Km circumference) with 6 interaction regions  Ion Beams: Au + Au (or p + A)  s = 200 GeV/nucleon luminosity = 2  cm -2 s -1  Polarized proton: p + p  s = 500 GeV luminosity = 1.4  cm -2 s -1  Experiments: PHENIX, STAR, PHOBOS, BRAHMS

PHENIX Experiment  Physics Goals Search for Quark-Gluon Plasma Hard Scattering Processes Spin Physics  Experimental Appratus PHENIX Central Arms (e , , hadrons) PHENIX Muon Arms (   )

PHENIX Data Size Peak DAQ bandwidth in PHENIX is 20 MB/sec.  Ion Beams (Au + Au) 1. Minimum bias events (0.16 MB/event): Raw event rate = 1400 Hz (224 MB/sec) Trigger rate = 124 Hz (20 MB/sec) 2. Central events (0.4MB/event): Trigger rate = 50 Hz (20 MB/sec)  Polarized proton (p + p) All events (25 KB/event): Raw event rate = 250 KHz (6250 MB/sec) Trigger rate = 800 Hz (20 MB/sec)

RCF RHIC Computing Facility (RCF) provides computing facilities for four RHIC experiments (PHENIX, STAR, PHOBOS, BRAHMS). Typically RCF gets ~ 30 MB/sec (or a few TB/day) from the PHENIX counting house only through Gigabit network. Thus RCF is required to have complicated data storage and data handling systems. RCF has established an AFS cell for sharing files with remote institutions and NFS is the primary means through which data is made available to the users at the RCF. The similar facility is established at RIKEN (CC-J) as a regional computing center for PHENIX. Compact but effective system is also installed at Yonsei.

PHENIX Computing Environment Linux OS with ROOT PHOOL (PHenix Object Oriented Library): C++ class library (PHOOL) based on top of ROOT GNU build system Local Disks Database Reconstruction Farm Calibrations & Run Info Raw Data DST Data Big Disk HPSS Mining & Staging Analysis Jobs Tag DB Counting House Pretty Big Disk Raw Data

Data Carousel using HPSS To handle annual volume of 500TB from PHENIX only, High Performance Storage System (HPSS) is used as Hierarchical Storage system with tape robotics and disk system. IBM computer (AIX4.2) organizes the request of users to retrieve data without chaos. PHENIX used ten 9840 and eight 9940 drives from STK. The tape media costs about $1/GB.

“ORNL” software carousel server mySQL database filelist HPSS tape HPSS cache pftp rmine0x client pftp CAS data mover CAS local disk NFS disk Data carousel architecture

Disk Storage at RCF The storage resources are provided by a group of SUN NFS servers with 60TB of SAN based RAID arrays backed by a series of StorageTek tape libraries managed by HPSS. Vendors of storage disks are Data Direct, MTI, ZZYZX, and LSI.

Linux Farms at RCF CRS (Central Reconstruction Server) farms are dedicated to the processing of raw event data to generate reconstructed events (strictly batch systems without being available for general users). CAS (Central Analysis Server) farms are dedicated to the analysis of the reconstructed events (mix of interactive and batch systems). The LSF, the Load Sharing Facility, manages batch jobs. There are about 600 machines (dual CPU, IGB memory, 30GB local disks) at RCF and about 200 machines are allocated for PHENIX.

offline software technology analysis framework  C++ class library (PHOOL) based on top of ROOT base class for analysis modules “tree” structure for holding, organizing data can contain raw data, DSTs, transient results uses ROOT I/O database  using Objectivity OODB for calibration data, file catalog, run info, etc. expecting ~100 GB/year of calibration data code development environment  based heavily on GNU tools (autoconf, automake, libtool)

PHENIX CC-J The PHENIX CC-J at RIKEN is intended to serve as the main site of computing for PHENIX simulations, a regional Asia computing center for PHENIX, and as a center for SPIN physics analysis. Network switches required to connect HPSS servers, the SMP data servers, and the CPU farms at RCF. In order to exchange data between RCF and CC-J, a proper bandwidth of the WAN between RCF and CC-J is required. CC-J has CPU farms of 10K SPECint95, tape storage of 100 TB, disk storage of 15 TB, tape I/O of 100 MB/sec, disk I/O of 600MB/sec, and 6 SUN SMP data server units.

Comparable mirror image into Yonsei by “Explicit” copy of the remote system Usage of the local cluster machines Similar operation environment (same OS, and similar hardware spec) 1. Disk sharing through NFS One installation of analysis library and sharing by other machines 2. Easy upgrade and management Local clustering Unlimited network resources between the cluster machines by using 100Mbps (No NFS lagging and instant X-display as an example) Current number of the cluster machines = 2 (2CPUs) + 2 (as RAID) File transfers from RCF Software update by copying shared libraries (once/week, takes less than about 1 hour) Raw data copy using “scp” or BBFTP (~1GB/day) Situations at YONSEI

Yonsei Computing Resources Yonsei Linux boxes for PHENIX analysis use 4 desktop boxes in a firewall (Pentium III/IV) Linux (RedHat 7.3, Kernel , GCC ) ROOT(ROOT 3.01/05) One machine has all software required for PHENIX analysis Event generation, reconstruction, analysis Remaining desktops share one library directory with the same kernel and compiler etc… via NFS 2 large RAID disk box with several IDE HDDs (~500G X 2) and several small disks (total ~500G) in 2 desktops Compact but effective system for small user group

Yonsei Computing Resources Linux (RedHat 7.3, Kernel ,GCC ) ROOT(ROOT 3.01/05) Database Reconstruction Calibrations & Run Info Raw Data & DST Big Disk(480G X 2) RAID tools for Linux Analysis Jobs Tag DB Gateway Library(NFS) OBJY P4 2G 480G DISK P3 1G P4 1.3G 480G RAID DISK Firewall 100Mbps PHENIX Library