PRIN STOA-LHC: STATUS BARI BOLOGNA-18 GIUGNO 2014 Giorgia MINIELLO G. MAGGI, G. DONVITO, D. Elia INFN Sezione di Bari e Dipartimento Interateneo di Fisica dell’Università e del Politecnico di Bari

BARI PRIN Activities - OUTLINE TEST AND COMPARISON of FILE ACCESS PERFORMANCES VIA XROOTD versus LOCAL ACCESS SET UP AND DEPLOYMENT OF AN ELASTIC CLUSTER BASED ON OPENSTACK IaaS AND CONFIGURED FOR ALICE VIRTUAL ANALYSIS FACILITY A BRIEF OVERVIEW ON BARI TESTBED SET-UP FUTURE GOALS 18/06/14PRIN STOA-LHC: STATUS BOLOGNA

TEST AND COMPARISON of FILE ACCESS PERFORMANCES VIA XROOTD versus LOCAL ACCESS H.E.P. Analysis used: “Observation of a Higgs Boson and measurements of its properties through the decay channel H->ZZ->4l with the CMS experiment”. Dataset: DataMuParked/Run2012A-22Jan2013-v1/AOD. Study of the wall clock time distributions of jobs running two steps of this analysis (one at a time!): STEP 1 more I/O intensive (~ 75% of the whole job duration spent in I/O activitIes, and the remaining ~25% spent in computing activities) and STEP 2 more CPU intensive (~83% computing, ~17% I/O). A Set of files taken from the dataset each job accessed just one file, once reading it on local file system lustre and once via remote file access protocol XROOTD. For every file 100 jobs were submitted to ensure statistics. Only XROOTD redirector can choose the server on which the file requested will be open: A study of wall clock time distributions server by server has also been performed splitting the histogram related to EU XROOTD servers site by site (e.g.: ES, CH, DE, KR…). 18/06/14PRIN STOA-LHC: STATUS BOLOGNA

TEST AND COMPARISON of FILE ACCESS PERFORMANCES VIA XROOTD versus LOCAL ACCESS- RESULTS (1/2) STEP 1 of the analysis: a shift factor between the position of the peaks belonging to the wall clock time distributions of jobs accessing files via xrootd (INCLUDING EU servers) and locally has been calculated. It has been evaluated to be only ~1.1 when considering ONLY IT XROOTD servers and ~1.8 when including all EU servers. A shift factor between EU xrootd histogram's peak and IT xrootd histogram's peak has been evaluated to be ~1.43. Studying the performances about accessing files separating xrootd servers: the wall clock values of jobs opening files on ITALIAN XROOTD servers (BARI + CNAF) are only 15% greater than those of jobs accessing files locally; the peaks belonging to Bari and CNAF histograms are quite compatible (within few units in percentage). The gap between the EU peak and the peaks belonging to IT histograms highlights that the redirection performed by XROOTD on EU servers (OUTSIDE ITALY) clearly constitues a bottleneck in remote data access STEP 2 of the analysis: the new input files (the output files of STEP 1) have been previously allocated on Bari lustre storage and accessed using both methods: Shift factor reduced to ~1.05 in this step. 18/06/14PRIN STOA-LHC: STATUS BOLOGNA

TEST AND COMPARISON of FILE ACCESS PERFORMANCES VIA XROOTD versus LOCAL ACCESS- RESULTS (2/2) 18/06/14PRIN STOA-LHC: STATUS BOLOGNA STEP 1STEP 2

CREATING AN ELASTIC CLUSTER FOR V.A.F. ON PRISMA TESTBED Using the Bari PRISMA TESTBED based on OpenStack, a cluster has been set up and configured for the ALICE VAF; EC2 interface was already available on BARI PRISMA TESTBED; Problems of V.M. contextualization solved in collaboration with Torino and other sites: on Bari PRISMA testbed a “configuration drive” is directly mounted on VMs instead of METADATA SERVER At present, the new version of the CernVM ( ), is able to support the contextualization through “ConfigDrive” (on OpenStack) as an alternative to the “metadata server”. Actually, a direct connection has been used for CernVMFS configuration, but a configuration with proxy is on schedule. The performances of the V.A.F. are under test. We started changing gradually the number of nodes to be requested 18/06/14PRIN STOA-LHC: STATUS BOLOGNA

BARI PRISMA Testbed set-up Rabbit cluster/AMQP Galera Cluster replication HAProxy, keepalived ha1.ba.infn.it ha2.ba.infn.it MySQL queries ha.ba.infn.it MyS QL AM QP Pacemaker/Corosync Active/Passive Pacemaker/Corosync Active/Passive OpenStac k Controller API servers OpenStac k Controller API servers OpenStac k Network Controller OpenStac k Network Controller OpenStac k Network Controller OpenStac k Network Controller OpenStac k Controller API servers OpenStac k Controller API servers OpenStack Public APIs compute node GlusterFS Swift Ceph Object Storage Cluster Mon Cinder Architectural schema by Marica Antonacci

DIMENSIONS AND FEATURES OF INFN BARI/UNIBA TESTBED Implemented within PON-PRISMA project The final configuration foreseen for the testbed is: 500 CPU/core 3TB RAM 110 TB disk (replica 3) 10 Gbit/s internal network 10 Gbit/s geographical network 256 Public IP DIRECT ACCESS At the moment we have 300 CPU/core already available 18/06/14PRIN STOA-LHC: STATUS BOLOGNA

Future Goals Configuration in production of an italian XROOTD redirector in collaboration with PISA This will solve problems of performance and scalability Study of the VAF performances: changing parameters of the cluster configuration (e.g. max number of nodes) testing pilot analysis tasks (VAF vs standard batch analysis on the Grid) Configuring the V.A.F. for CVMFS access via squid proxy; Contribution to the development and testing of the Virtual Storage Element; Configuration of an Analysis Facility based on PROOF, also for CMS 18/06/14PRIN STOA-LHC: STATUS BOLOGNA