1. Grid Computing - DCC/FCUP
The middleware
Grid Computing - DCC/FCUP

2. Disclaimer
This presentation is based on materials provided and authorized by the EGEE project and is available to download and use according to the terms of the following license:

3. OUTLINE The EGEE Project The gLite middleware Objective
Relationship to other projects
The gLite middleware
Middleware decomposition
Foundation
High-level services

4. Part I
The EGEE Project

5. The EGEE project EGEE EGEE-II EGEE-III Objectives
1 April 2004 – 31 March 2006
71 partners in 27 countries, federated in regional Grids
EGEE-II
1 April 2006 – 31 March 2008
91 partners in 32 countries
13 Federations
EGEE-III
1 April 2008 – 31 March 2010
More than 120 partners
Objectives
Large-scale, production-quality infrastructure for e-Science
Attracting new resources and users from industry as well as science
Improving and maintaining “gLite” Grid middleware
US partners in EGEE-II:
Univ. Chicago
Univ. South. California
Univ. Wisconsin
RENCI

6. Main lines of the EGEE project
Infrastructure operation
Currently includes sites across 39 countries
Continuous monitoring of grid services & automated site configuration/management
Middleware
Production quality middleware distributed under business friendly open source licence
User Support - Managed process from first contact
through to production usage
Training
Expertise in grid-enabling applications
Online helpdesk
Networking events (User Forum, Conferences etc.)
Interoperability
Expanding geographical reach and interoperability with related infrastructures
TWGRID
KnowARC

7. Applications on EGEE Applications from an increasing number of domains
Astrophysics
Computational Chemistry
Earth Sciences
Financial Simulation
Fusion
Geophysics
High Energy Physics
Life Sciences
Multimedia
Material Sciences …
Book of abstracts:

8. EU projects related to EGEE
GRID

9. Sustainability: Beyond EGEE-III
Need to prepare for permanent Grid infrastructure
Ensure a reliable and adaptive support for all sciences
Independent of short project funding cycles
Infrastructure managed in collaboration with national grid initiatives
Expand the idea and problems of the JRU
EGI

10. Part II The gLite middleware Programming the Grid with gLite

11. Middleware structure
Applications
Applications have access both to Higher-level Grid Services and to Foundation Grid Middleware
Higher-Level Grid Services are supposed to help the users building their computing infrastructure but should not be mandatory
Foundation Grid Middleware will be deployed on the EGEE infrastructure
Must be complete and robust
Should allow interoperation with other major grid infrastructures
Should not assume the use of Higher-Level Grid Services
Higher-Level Grid Services
Workload Management
Replica Management
Visualization
Workflow
Grid Economies
...
Foundation Grid Middleware
Security model and infrastructure
Computing (CE) and Storage Elements (SE)
Accounting
Information and Monitoring
Overview paper
OMII-Europe All-Hands meeting, Bologna, February 2007

12. gLite Services Decomposition
6 High Level Services
+ CLI & API
Legend:
Available
Foreseen in the architecture (only Job provenance was available in the end of EGEE-II)
Site proxy – allows outbound connectivity from hidden networks

13. gLite components UI: User Interface CE: Computing Element
SE: Storage Element
WN: Worker Node
WMS: Workload Management System
VOMS: Virtual Organization Membership Service
LB: Logging and Bookkeeping
MonBOX: monitoring
LFC: Logical File Catalog
BDII: Berkeley Database Information Index, stores all infomation about the resources available in the grid infrastructure

14. Job Workflow in gLite LFC Catalog Information Service Resource BrokerUI
JDL
Input “sandbox”
DataSets info
voms-proxy-init
Information
Service
Output “sandbox”
SE & CE info
Resource
Broker
Output “sandbox”
Input “sandbox” + Broker Info
Expanded JDL
Job Submit Event
Job Query
Job Status
Publish
Author.
&Authen.
Storage
Element
Globus RSL
Job Submission
Service
Job Status
Logging &
Book-keeping
Computing
Element
Job Status

15. Job Workflow in gLite LFC Catalog Information Index Resource BrokerUI
JDL
Input “sandbox”
DataSets info
voms-proxy-init
Information
Index
Output “sandbox”
SE & CE info
Resource
Broker
Output “sandbox”
Expanded JDL
Job Submit Event
Job Query
Job Status
Input “sandbox” + Broker Info
Publish
Author.
&Authen.
Storage
Element
Globus RSL
Job Submission
Service
Job Status
Logging &
Book-keeping
WMProxy
Computing
Element
Job Status

16. High Level Services: Workload Manag.
Resource brokering, workflow management, I/O data management
Web Service interface: WMProxy
Task Queue: keep non matched jobs
Information SuperMarket: optimized cache of information system
Match Maker: assigns jobs to resources according to user requirements
Job submission & monitoring
Condor-G
ICE (to CREAM)
External interactions:
Information System
Data Catalogs
Logging&Bookkeeping
Policy Management system (G-PBox)
CREAM: Computing Resource Execution and Management
ICE: Interface to CREAM Environment

17. Grid Foundation: Security
Authentication based on X.509 PKI infrastructure
Certificate Authorities (CA) issue (long lived) certificates identifying individuals (much like a passport)
Commonly used in web browsers to authenticate to sites
Trust between CAs and sites is established (offline)
In order to reduce vulnerability, on the Grid user identification is done by using (short lived) proxies of their certificates
Proxies can
Be delegated to a service such that it can act on the user’s behalf
Include additional attributes (like VO information via the VO Membership Service VOMS)
Be stored in an external proxy store (MyProxy)
Be renewed (in case they are about to expire)

18. Grid Foundation: Security
Local Centre Authorization Service (LCAS) handles authorization requests to the local computing fabric
Local Credential Mapping Service (LCMAPS) provides all local credentials needed for jobs allowed into the fabric.
Batch Local ASCII Helper
The protocol (BLAHP): provides a set of plain ASCII commands used by Condor-C (and CREAM) to manage jobs on the batch systems.
The daemon (BLAHPD): implements the helper daemon responsible for converting BLAHP commands into batch system actions, interpreting their results and reporting them in BLAHP format.

19. Grid foundation: Information Systems
Generic Information
Provider (GIP)
Provides LDIF
information about
a grid service in
accordance to the
GLUE Schema
BDII: Information system in gLite 3.0 (by LCG)
LDAP database that is
updated by an external process
More than one DBs is used
separate read and write
A port forwarder is used internally
to select the correct DB
GIP
Cache
Provider
Plugin
LDIF
File
Config
File
LDIF: Lightweight Directory Interchange Format
LDAP: Lightweight Data Access Protocol
GLUE: Grid Laboratory Uniform Environment
BDII: Berkeley Datbase Information Index

20. Grid foundation: Information Systems
R-GMA: provides a uniform method to access and publish distributed information and monitoring data
Used for job and infrastructure monitoring in gLite 3.0
Working to
add
authorization
Service Discovery:
Provides a standard set of methods for locating Grid services
Currently supports R-GMA, BDII and XML files as backends
Will add local cache of information
Used by some DM and WMS components in gLite 3.0

21. Grid foundation: Computing Element
Three flavours available now:
LCG-CE (GT2 GRAM)
In production now but will be phased-out next year
gLite-CE (GSI-enabled Condor-C)
Already deployed but still needs thorough testing and tuning. Being done now
CREAM (WS-I based interface)
Deployed on the JRA1 preview test-bed. After a first testing phase will be certified and deployed together with the gLite-CE
Our contribution to the OGF-BES group for a standard WS-I based CE interface
CREAM and WMProxy demo at SC06!
BLAH is the interface to the local resource manager (via plug-ins)
CREAM and gLite-CE
Information pass-through: pass parameters to the LRMS to help job scheduling
WMS,
Clients
Information
System
Grid
Computing
Element
bdII
R-GMA
CEMon
Site
glexec +
LCAS/
LCMAPS
BLAH WN
LRMS

22. Grid foundation: Accounting
APEL: Uses R-GMA to propagate and display job accounting information for infrastructure monitoring
Reads LRMS log files provided by LCG-CE and BLAH
Preparing an update for gLite 3.0 to use the files from BLAH
DGAS: Collects, stores and transfers accounting data. Compliant with privacy requirements
Reads LRMS log files provided by LCG-CE and BLAH.
Stores information in a site database (HLR) and optionally in a central HLR. Access granted to user, site and VO administrators
Not yet certified in gLite 3.0. Deployment plan:
DGAS is in certification at INFN
It will send records to the GOC via DGAS2APEL
HLR: Home Location Registers: manage user and resource accounts

23. Grid foundation: Storage Element
Common interface: SRMv1, migrating to SRM v2.2
Various implementation from LCG and other external projects
disk-based: DPM, dCache / tape-based: Castor, dCache
Support for ACLs in DPM (in future in Castor and dCache)
synchronization of ACLs between SEs
Common rfio library for Castor and DPM being added
Posix-like file access:
Grid File Access Layer (GFAL) by LCG
Support for ACL in the SRM layer (currently in DPM only)
Support for SRMv2
gLite I/O
Support for ACLs from the file catalog and interfaced to Hydra for data encryption
Not certified in gLite 3.0. To be dismissed when all functionalities will be also available in GFAL.
Hydra: encrypts files and stores them on normal storage elements

24. High Level Services: Catalogues
File Catalogs
LFC from LCG
interfaced to POOL (Disk Pool Manager – DPM).
LFC replication and backup.
Hydra: stores keys for data encryption
interfaced to GFAL
Released with gLite 3.1
AMGA Metadata Catalog: generic metadata catalogue
Joint ARDA development. Used mainly by Biomed

25. High Level Services: File transfer
FTS: Reliable, scalable and customizable file transfer
Manages transfers through channels
mono-directional network pipes
between two sites
Web service interface
Automatic discovery of services
Support for different user and administrative roles
Adding support for
pre-staging and new
proxy renewal schema
Support for SRMv2.2,
delegation,
VOMS-aware proxy
renewal in certification

26. High Level Services: Workload mgmt.
WMS helps the user accessing computing resources
Resource brokering, management of job input/output, ...
LCG-RB: GT2 + Condor-G
To be replaced when the gLite WMS proves to be reliable
gLite WMS: Web service (WMProxy) + Condor-G
Management of complex workflows (DAGs) and compound jobs
bulk submission and shared input sandboxes
support for input files on different servers (scattered sandboxes)
Support for shallow resubmission of jobs
Job File Perusal: file peeking during job execution
Supports collection of information from CEMon, BDII, R-GMA and from DLI and StorageIndex data management interfaces
Support for parallel jobs (MPI) when the home dir is not shared
Deployed for the first time in gLite 3.0

27. WMS/LB/UI and CE New WMS deployed and thoroughly debugged
CMS: 100 collections * 200 jobs/collection, 3 UIs, 33 CEs
~ 2.5 h to submit jobs
0.5 seconds/job
~ 17 hours to transfer jobs to a CE
3 seconds/job
26K jobs/day
Negligible failure rate due to WMS
Shallow resubmission
failure rate drops to less than 1% with
3 resubmissions
CMS
Stability problems
investigating also other deployment scenarios to make it more robust
gLite CE still to be tested and optimized
ATLAS

28. High Level Services: Workflows
Direct Acyclic Graph (DAG) is a set of jobs where the input, output, or execution of one or more jobs depends on one or more other jobs
A Collection is a group of jobs with no dependencies
basically a collection of JDL’s
nodeE
nodeC
nodeA
nodeD
nodeB
A Parametric job is a job having one or more attributes in the JDL that vary their values according to parameters
Using compound jobs it is possible to have one shot submission of a (possibly very large, up to thousands) group of jobs
Submission time reduction
Single call to WMProxy server
Single Authentication and Authorization process
Sharing of files between jobs
Availability of both a single Job ID to manage the group as a whole and an ID for each single job in the group

29. High Level Services: Job Information
Logging and Bookkeeping service
Tracks jobs during their lifetime (in terms of events)
LBProxy for fast access
L&B API and CLI to query jobs
Support for “CE reputability ranking“: maintains recent statistics of job failures at CE’s and feeds back to WMS to aid planning
Job Provenance: stores long term job information
Supports job rerun
helps unloading the L&B
Released with gLite 3.1.

30. Highlights: Job Priorities
Applications ask for the possibility to diversify the access to fast/slow queues depending on the user role/group inside the VO
GPBOX is a tool that provides the possibility to define, store and propagate fine-grained VO policies
based on VOMS groups and roles
enforcement of policies at sites: sites may accept/reject policies

31. Summary gLite 3 is the next generation middleware for grid computing
developed according to a well defined process
controlled by the EGEE Technical Coordination Group
deployed on the EGEE production infrastructure
More than 200 sites
development is continuing to provide increased robustness, usability, and functionality
On the preview testbed
CREAM, Job Provenance, glexec on the WNs, GPBOX
gLite sources: