The Disk Resource Manager A Berkeley SRM for Disk Cache Implementation and Testing Experience on the

1
The Disk Resource ManagerA Berkeley SRM for Disk
CacheImplementation and Testing Experience on
the OSG

• Jorge Luis Rodriguez
• IBP/Grid Mini-Workshop
• Apr 7-8, 2005

2
Storage in Grid3

• No real Storage Element in Grid3
• Defined a set storage locations to enable jobs to
  run at a site
• The middleware location
• Grid3 sharing recommended, the VDT_LOCATION
• Shared across the entire CE and chmod 0777 ?
• APP Applications are installed here
• DATA Users scratch space lifetime per exp.
  run
• TMP Another user scratch space, lifetime per
  job
• Non-shared local to worker nodes
• WNTMP Also chmod 0777, lifetime per job
• Very simplistic but something was needed to get
  us off the ground

On the CE
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DRM Service Deployment Goals

• To provide managed tactical storage to an OSG
  site
• Apply SRM interface to DATA shared space
• Storage space reservation
• Storage request scheduling
• Should function in the OSG environment
• OSG Packaging
• pacman
• OSG MIS
• Publish relevant service parameters (port s,
  Service names)
• OSG Authorization
• Multi-VO, VOMS managed gridmap-file

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Service Description

• Brief overview of the DRM Service
• CORBA based service
• Based on SRM v.1.1 specification
• Movement of files into and out of SRM cache
• Default Lifetime, space quota, caching and
  queuing policies are supported
• Can be used through command-line DRM clients
• Web Service component is provided by JAVA based
  wrapper
• interoperable with other SRMs (e.g. dCache-SRM)
• Can be used through srmcp fermilab client

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Service Description

• DRM dependencies
• Functions on top of ordinary UNIX file systems
  local, NFS
• Binaries available for RH7.x and RHEL 3
• Statically linked and self contained
• Requires JAVA 1.4
• Requires data movement services gTK, gsiftp

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Working in the OSG
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OSG Organization
Technical Groups
Advisory Committee
Labs
Service Providers
Executive Board (8-15 representatives Chair,
Officers)
Sites
Researchers
VOs
Research Grid Projects
Enterprise
OSG Council (all members above a certain
threshold, Chair, officers)
Core OSG Staff (few FTEs, manager)
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The DRM Activity
TG-Storage

• UFlorida
• LBL
• Argonne
• Vanderbilt
• FNAL

OSG deployment
Testbed
Plone website
Readiness Plan
Integration
DRM
Documents
Monitoring
Privilege
Privilegec
Privilegec
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The DRM Activity

• Readiness Plan
• Details what we plan to do to get the service
  ready for deployment in the OSG
• Examine deployment strategies
• Deploy with other CE services
• Deploy as stand alone service (on separate host)
• Examine impact on other OSG services
• Authorization, monitoring, packagin
• Develop testing alogrithum
• Include service verification
• Include mock up and real application tests

10
The DRM Activity

• Logistics and Documentation
• Telecon meetings on a semi-regular basis
• e-mail list osg-drm_at_opensciencegrid.org
• Plone website plone.opensciencegrid.org
• Installation instructions
• Meetings and minutes
• Collection of interesting document
• DRM testbed site information

11
Installation and Configuration
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Installation

• DRM is included a part of VDT1.3.3
• DRM vers 1.2.4 in the VDT
• The CORBA components are installed and configured
  by the VDT
• Can be deployed with everything else
• How its currently deployed in DRM testbed
• Canonical Grid3 site
• Can also be deployed stand alone
• VDT will handle dependencies
• Also being tried in DRM testbed

13
Configuration

• Should install as a non-privileged user (srm)
• Service provider recommends this for security
  reasons
• File system configuration
• These recommendations are a work in progress!
• Allocate a separate partition for the cache
• RW for the service uid, all others RO
• Can and should use service certificates
• Auto configuration and sysV startup script
  included
• Hand entered parameters will likely be required
• Web Service configuration is now working

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Testing and Validation
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Site Level Testing

• CORBA and Java Web Services are running
• Simple File movement exercise
• Move files into and out of the DRM cache via the
  SRM interface
• Move files into and out of from a remote DRM
  client
• Move files into and out of DRM cache from a
  remote SRM-dCache client
• DRM test harness (from LBL team)
• Included with DRM vers 1.2.4
• Will be part of the overall site verification

16
Application Level Test

• Simplified (mockup) application test will
  include
• stage file into DRM cache from remote
  DRM/SRM-dCache client
• Execute job that access staged in file in DRM
  cache via POSIX calls
• Job creates an output file on local storage
  (WNTMP or TMP)
• Job moves file from local storage into local DRM
  cache
• Job moves file from DRM cache to SRM managed or
  regular remote location
• Testing by real Application(s)
• Make and document recommendations for use of DRM
  services in job work flow
• Make DRM enabled sites available for application
  testers
• Schedule with application administrators
• Monitor activity by both site and application
  administrators

17
Service Monitoring

• Will need input from Service Provider as to what
  to monitor and what to measure
• Performance of storage requests
• How does the reservation system work
• How does storage request scheduling function
• Resource load from DRM activities
• Impact on server load
• Impact on other running services

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Pending Issues Next Steps
19
Where are We Now?

• DRM will NOT be ready for OSG-0
• Service was deployed on two OSG based sites
• Could not complete simple service operational
  exercises in time for OSG deployment decision
• Need more user effort (testbed)
• Dependency on other services critical
• Service difficult to use due to lack of
  documentation
• Ongoing service development, changes and new
  significant new features between versions
• Will try for next OSG relase
• OSG integration is very busy with other services
  anyway

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Where Are We Now?

• Communication channels created
• plone activity, email lists and meetings
• Coordinating with OSG-TG
• Four sites in the readiness tesbed
• Argonne Ed May
• Buffalo Mark Green
• Florida Jorge Rodriguez
• LBL Alex Sim (DRM developers)

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Where Are We Now?

• Activities now focused on using DRM software
• CORBA services installed and used
• Exercised file movement with gsiftp and SRM
• Files moved into DRM cache worked OK
• Problems with new/old proxies
• Web Services
• All of these are now up and running out of the
  box
• So far only experts have operated the service
  using these
• Need to continue going through the procedures
  outlined in the readiness

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Next Steps

• Continue to work out kinks in the installation
  and configuration procedures
• Feed those back into the VDT packaging
• Run through the testing and validation steps
  outlined in slides 8 through 11
• Understand, document and communicate the service
  functionality
• To OSG site admins
• Impact on an individual site and services
• Impact on OSG grid wide services
• To OSG application community
• How will it impact on previously used work flows?
• What other changes are needed effectively use the
  new services?