Doug Benjamin Duke University ANL ATLAS Analysis Center prototype Tier 3 Used to develop all of the scripts needed to setup a Tier 3 site Used to test tools and software to train others ID: 785990
Download The PPT/PDF document "Duke and ANL ASC Tier 3 (stand alone Tie..." is the property of its rightful owner. Permission is granted to download and print the materials on this web site for personal, non-commercial use only, and to display it on your personal computer provided you do not modify the materials and that you retain all copyright notices contained in the materials. By downloading content from our website, you accept the terms of this agreement.
Slide1
Duke and ANL ASC Tier 3(stand alone Tier 3’s)
Doug Benjamin
Duke University
Slide2ANL ATLAS Analysis Center
“prototype” Tier 3
Used to develop all of the scripts needed to setup a Tier 3 site –
Used to test tools and software to train others
Expect it to grow as the number of users at the ASC increases
Developing puppet configurations at this site
Supported by DPB (very part time)
Use
Xrootd.org
Yum repository for most libraries
OSG Yum repository for the
gridftp
bits
Slide3“baseline” Tier 3g public/private networks
Head = redirector
Standalone xrootd data server
Xrootd data servers all on private network only
Clustered xrootd storage
Slide4Head Node/Redirector
Stand alone
Xrootd
data server
worker Node/ xrootd data serverworker Node/ xrootd data server
worker Node/ xrootd data server
Private
network
Xrootd clustered
storage
(private network)
Baseline Tier 3 (public/private network)
All data access within cluster (LAN) via private network
Use case 2. – storage on worker node data servers as part of Federation
Physical machine w/ local
xrootd functionalityOverlay xrootd functionality
Public IP network
Head node
xrootd
Proxy (public network)
Head node -
Xrootd
read-only redirector(private network)
Xrootd
read-only data server(private network)
Xrootd
read-only data server(private network)
Xrootd
read-only data server(private network)
Outgoing read only data flow
Slide5Xrootd configuration
Wiki page with example configuration
https://twiki.cern.ch/twiki/bin/view/Atlas/Tier3gXrootdSetup
Know issues
“sss” xrootdfsFrm checksuming turned off - Due to configuration of the data servers (oss.localroot).
Slide6Duke Tier 3Support
Department system admin’s
DPB (very part time)
Puppet helps reduce the loads
Disk heavy worker nodes and on big file server (SL 6)Stand alone SL 5 gridftp server (used a proxy server)Use Xrootd.org Yum repository for most librariesOSG Yum repository for the gridftp bits
Slide7Head Node/Redirector
Stand alone
Xrootd
data server
worker Node/ xrootd data serverworker Node/ xrootd data server
worker Node/ xrootd data server
Xrootd clustered
storage
Public network version of Baseline Tier 3
Use Case C. - data from all data servers (WN and stand alone)
Physical machine w/ local
xrootd
functionality
Overlay
xrootd functionality
Public IP networkHead node -Xrootd read-only redirector
Xrootd
read-only data server
Xrootd
read-only data server
Xrootd
read-only data server
Xrootd
read-only data server
Outgoing read only data flow
Outgoing read only data flow
Information flow to global redirector
Slide8Xrootd usage at Duke
Users begrudgingly are using
Xrootd
More senior folks like to use NFS like access
Then to use xrootdfs to access the storage Graduate students much more adaptable.