Universit degli Studi di Bari Corso di Laurea
Università degli Studi di Bari – Corso di Laurea Specialistica in Informatica “Tecnologia dei Servizi “Grid e cloud computing” A. A. 2009/2010 Giorgio Pietro Maggi giorgio. maggi@ba. infn. it, http: //www. ba. infn. it/~maggi Lezione 8 - 15 Dicembre 2009 Il materiale didattico usato in questo corso è stato mutuato da quello utilizzato da Paolo Veronesi per il corso di Griglie Computazionali per la Laurea Specialistica in Informatica tenuto nell’anno accademico 2008/09 presso l’Università degli Studi di Ferrara. Paolo Veronesi paolo. veronesi@cnaf. infn. it, pveronesi@unife. it http: //www. cnaf. infn. it/~pveronesi/unife/ Tecnologia dei Servizi “Grid e cloud computing” - Lezione 8 0
Today’s focus: Information Services Execution Management • Job description & submission • Scheduling • Resource provisioning Data Services • Common access facilities • Efficient & reliable transport • Replication services Resource Management Self-Management • Discovery • Monitoring • Control • Self-configuration • Self-optimization • Self-healing OGSA Information Services Security • Registry • Notification • Logging/auditing • Cross-organizational users • Trust nobody • Authorized access only DONE OGSA “profiles” Web services foundation DONE Tecnologia dei Servizi “Grid e cloud computing” - Lezione 8 1
Outline p What is the Information System p Data Model: the GLUE Schema p Overview p Core entities p Open. LDAP server introduction LCG p Information Service Architecture p Top BDII and Site BDII p Information upgrade process Tecnologia dei Servizi “Grid e cloud computing” - Lezione 8 2
Information System p What is? n p Why? n n n p System to collect information on the state of resources To discover resources of the grid and their nature To have useful data that helps who is in charge of managing the workload to do it more efficiently. To check for health status of resources. How? n n n Monitoring state of resources locally and publishing right information on the information system. Adopting a data model that MUST be well known to all components that want to access monitored information Using different approaches that we are going to investigate in next slides Tecnologia dei Servizi “Grid e cloud computing” - Lezione 8 3
Design of Information Systems p About Measures n n n p About the gathering of Information n p How and when collected info should be published? Where should collected info be stored? How long should this info be maintained in the storage? Querying the Information System n n n p Measures SHOULD be sensitive to the aim the users want to achieve. Measures SHOULD be enough accurate to be considered valid. Rate of taking measures MUST be adequate to be used. Where should queries be sent to have a response? What syntax and protocols have to be adopted to make queries? What is the adopted data model to describe resources? Security n n Who is allowed to execute queries against the IS and what type of queries is he allowed to do? Management of user rights and credentials. Tecnologia dei Servizi “Grid e cloud computing” - Lezione 8 4
Adopted Information Systems p The BDII (Berkley DB Information Index) n has been adopted in LCG middleware as the Information System provider. n It is an evolution of the Globus Meta Directory System (MDS) n g. Lite actually adopts BDII as Information System. n It is based on Lightweight Directory Access Protocol (LDAP) servers. p The Relational Grid Monitoring Architecture (R-GMA) n Is an implementation of the Grid Monitoring Architecture (GMA) standardized by the Global Grid Forum (GGF) n It is a relational implementation of the GMA n It is strongly Web Services Oriented n To be adopted by next releases of the g. Lite middleware ? ? Tecnologia dei Servizi “Grid e cloud computing” - Lezione 8 5
The LDAP Protocol: Generalities LDAP (Lightweight Directory Access Protocol) √ It establishes the transport and format of the messages used by a client to access a directory √ LDAP can be used as access protocol for a large number of databases √ It provides a standard data model; the DIT (Directory Information Tree) √ It is the internal protocol used by the EGEE/LCG services to share information Tecnologia dei Servizi “Grid e cloud computing” - Lezione 8 6
The LDAP Protocol: DIT o = grid (root of the DIT) ► LDAP structures data as a tree ► Following a path from the node c= US back to the root of the DIT, a unique name is built (the DN): c=Switzerland c=Spain st = Geneva “id=pml, ou=IT, or=CERN, st=Geneva, c=Switzerland, o=grid” or = CERN ou = IT object. Class: person cn: Patricia M. L. phone: 5555666 office: 28 -r 019 Tecnologia dei Servizi “Grid e cloud computing” - Lezione 8 id = pml ou = EP id=gv 7 id=fd
The LDAP Protocol: The Data Model ► The LDAP information model is based on entries ► These are attribute collections defined by a unique and global DN (Distinguished Name) ► Information is organized in a tree-like structure. A special attribute, objectclass, can be defined for each entry. It defines the classes tree corresponding to this entry. This attribute can be used to filter entries containing that object class ► The information is imported and exported from and to the LDAP server by LDIF files (LDAP Data Interchange Format) dn: <distinguished name> objectclass: <objectclassname> <attributetype>: <attributevalue> Tecnologia dei Servizi “Grid e cloud computing” - Lezione 8 ► Those fields delimited by <> can be defined by the application following a certain schema ►The schema describes the attributes and the types associated with the data objects 8
Information Service Systems • The g. Lite Data Model is based on Grid Laboratory Uniform Environment (GLUE) Schema • The IS architecture used in g. Lite is Berkeley DB Information Index (BDII) – – – has been adopted in LCG middleware as the Information System provider It is an evolution of the Globus Meta Directory System (MDS) It is based on Lightweight Directory Access Protocol (LDAP) servers Tecnologia dei Servizi “Grid e cloud computing” - Lezione 8 9
The Data Model: GLUE Schema Tecnologia dei Servizi “Grid e cloud computing” - Lezione 8 10
GLUE: overview • GLUE: Grid Laboratory Uniform Environment • It’s an information model that describe all those resources that partecipate in the Grid system and that are requested to be discoverable and monitored • The same information can be retrieved from different BDIIs relying on different technology (e. g. R-GMA) Tecnologia dei Servizi “Grid e cloud computing” - Lezione 8 11
GLUE Schema • Describe the Grid resources information stored in the IS • Independent from the underlying technology • Actual release is mapped on – – – • LDAP XML Class. Ad (Condor Matchmaking language) The entities of the GLUE Schema are organised hierarchically – Include the concept of Site, Cluster, Computing Element, Storage Element, and an abstraction of service Tecnologia dei Servizi “Grid e cloud computing” - Lezione 8 12
GLUE Schema Structure Site Collection of resources owned by a sinle organisation. Contains info on the location, the administrator, web page and so on 1 1 1 * Service Description of deployed service Cluster * Set of heterogeneous resources. Contains info on shared directory 1 Host Contains details of hardware (features and performance) and software 1 VOview Sub-Cluster Set of homogeneous resources. Contains the size of the set Job * * State Info Policy * * Storage. Element Computing. Element Tecnologia dei Servizi “Grid e cloud computing” - Lezione 8 13
Site Element Tecnologia dei Servizi “Grid e cloud computing” - Lezione 8 14
GLUE: site Glue. Site. Unique. ID: TRIGRID-INFN-CATANIA Glue. Site. Name: TRIGRID-INFN-CATANIA Glue. Site. Description: LCG Site Glue. Site. User. Support. Contact: mailto: grid-prod@ct. infn. it Glue. Site. Sys. Admin. Contact: mailto: grid-prod@ct. infn. it Glue. Site. Security. Contact: mailto: grid-prod@ct. infn. it Glue. Site. Location: Catania, Italy Glue. Site. Latitude: 37. 54866 Glue. Site. Longitude: 15. 036076 Glue. Site. Web: http: //www. trigrid. it Glue. Site. Other. Info: TIER 1 Glue. Site. Other. Info: Trigrid Team Tecnologia dei Servizi “Grid e cloud computing” - Lezione 8 15
GLUE: service Glue. Service. Unique. ID: infn-rb-01. ct. trigrid. it: 7772 Glue. Service. Name: INFN-CATANIA-rb Glue. Service. Type: Resource. Broker Glue. Service. Version: 1. 2. 0 Glue. Service. Endpoint: infn-rb-01. ct. trigrid. it: 7772 Glue. Service. URI: unset Glue. Service. Access. Point. URL: not_used Glue. Service. Status: OK Glue. Service. Status. Info: No Problems Glue. Service. WSDL: unset Glue. Service. Semantics: unset Glue. Service. Start. Time: 1970 -01 -01 T 00: 00 Z Glue. Service. Owner: trigrid Glue. Service. Owner: cometa Glue. Service. Owner: inaf Glue. Service. Owner: alice Glue. Service. Access. Control. Rule: trigrid Glue. Service. Access. Control. Rule: cometa Glue. Service. Access. Control. Rule: inaf Glue. Service. Access. Control. Rule: alice Glue. Foreign. Key: Glue. Site. Unique. ID=INFN-CATANIA Tecnologia dei Servizi “Grid e cloud computing” - Lezione 8 16
Cluster Element Tecnologia dei Servizi “Grid e cloud computing” - Lezione 8 17
GLUE: cluster and subcluster Glue. Cluster. Name: infn-ce-01. ct. trigrid. it Glue. Cluster. Service: infn-ce-01. ct. trigrid. it: 2119/jobmanager-lcglsf-short Glue. Cluster. Service: infn-ce-01. ct. trigrid. it: 2119/jobmanager-lcglsf-long Glue. Cluster. Service: infn-ce-01. ct. trigrid. it: 2119/jobmanager-lcglsf-infinite Glue. Cluster. Service: infn-ce-01. ct. trigrid. it: 2119/jobmanager-lcglsf-cert Glue. Cluster. Service: infn-ce-01. ct. trigrid. it: 2119/jobmanager-lcglsf-cometa Glue. Cluster. Service: infn-ce-01. ct. trigrid. it: 2119/jobmanager-lcglsf-inaf Glue. Cluster. Service: infn-ce-01. ct. trigrid. it: 2119/jobmanager-lcglsf-alice Glue. Cluster. Service: infn-ce-01. ct. trigrid. it: 2119/jobmanager-lcglsf-cometa [. . ] Glue. Sub. Cluster. Physical. CPUs: 4 Glue. Sub. Cluster. Logical. CPUs: 4 Glue. Sub. Cluster. Tmp. Dir: /tmp Glue. Sub. Cluster. WNTmp. Dir: /tmp Tecnologia dei Servizi “Grid e cloud computing” - Lezione 8 18
GLUE: Host Glue. Host. Application. Software. Run. Time. Environment: GLITE-3_0_0 Glue. Host. Application. Software. Run. Time. Environment: INFN-CATANIA Glue. Host. Application. Software. Run. Time. Environment: MPICH [. . ] Glue. Host. Architecture. SMPSize: 4 Glue. Host. Benchmark. SF 00: 1937 Glue. Host. Benchmark. SI 00: 1483 Glue. Host. Main. Memory. RAMSize: 4096 Glue. Host. Main. Memory. Virtual. Size: 8192 Glue. Host. Network. Adapter. Inbound. IP: TRUE Glue. Host. Network. Adapter. Outbound. IP: TRUE Glue. Host. Operating. System. Name: Scientific Linux CERN Glue. Host. Operating. System. Release: 3. 0. 6 Glue. Host. Operating. System. Version: SLC Glue. Host. Processor. Clock. Speed: 2392 Glue. Host. Processor. Model: Dual Core Opteron 280 Glue. Host. Processor. Vendor: AMD Tecnologia dei Servizi “Grid e cloud computing” - Lezione 8 19
Computing Element Tecnologia dei Servizi “Grid e cloud computing” - Lezione 8 20
GLUE: Host Glue. CEName: cometa Glue. CEUnique. ID: infn-ce-01. ct. trigrid. it: 2119/jobmanager-lcglsf-cometa Glue. CEInfo. Gatekeeper. Port: 2119 Glue. CEInfo. Host. Name: infn-ce-01. ct. trigrid. it Glue. CEInfo. LRMSType: lsf Glue. CEInfo. LRMSVersion: 6. 1 Glue. CEInfo. Total. CPUs: 98 Glue. CEInfo. Job. Manager: lcglsf Glue. CEInfo. Contact. String: infn-ce-01. ct. trigrid. it: 2119/jobmanager-lcglsf-cometa Glue. CEInfo. Application. Dir: /opt/exp_soft Glue. CEInfo. Data. Dir: unset Glue. CEInfo. Default. SE: infn-se-01. ct. trigrid. it Glue. CEState. Estimated. Response. Time: 61713 Glue. CEState. Free. CPUs: 26 Glue. CEState. Running. Jobs: 70 Glue. CEState. Status: Production Glue. CEState. Total. Jobs: 70 Glue. CEState. Waiting. Jobs: 0 Glue. CEState. Worst. Response. Time: 123427 Glue. CEState. Free. Job. Slots: 26 Glue. CEPolicy. Max. CPUTime: 2880 Glue. CEPolicy. Max. Running. Jobs: 98 Glue. CEPolicy. Max. Total. Jobs: 0 Glue. CEPolicy. Max. Wall. Clock. Time: 2880 Glue. CEPolicy. Priority: -10 Glue. CEPolicy. Assigned. Job. Slots: 98 Glue. CEAccess. Control. Base. Rule: VO: cometa Tecnologia dei Servizi “Grid e cloud computing” - Lezione 8 21
Storage Element Information about the service (like Name, Port, URL) Storage Area Contains info of available and used disk space, file policies, access rules, etc. Access protocols Contains info about the protocols used to transfer files Tecnologia dei Servizi “Grid e cloud computing” - Lezione 8 22
GLUE: Storage Element Glue. SEUnique. ID: infn-se-01. ct. trigrid. it Glue. SEName: TRIGRID-INFN-CATANIA: srm_v 1 Glue. SEPort: 2811 Glue. SESize. Total: 16350 Glue. SESize. Free: 16350 Glue. SEArchitecture: multidisk Glue. Information. Service. URL: ldap: //infn-se-01. ct. trigrid. it: 2135/mds-vo-name=local, o=grid Tecnologia dei Servizi “Grid e cloud computing” - Lezione 8 23
GLUE: Storage Area Glue. SARoot: cometa: /dpm/ct. trigrid. it/home/cometa Glue. SAPath: /dpm/ct. trigrid. it/home/cometa Glue. SAType: permanent Glue. SALocal. ID: cometa Glue. SAPolicy. Max. File. Size: 10000 Glue. SAPolicy. Min. File. Size: 1 Glue. SAPolicy. Max. Data: 100 Glue. SAPolicy. Max. Num. Files: 10 Glue. SAPolicy. Max. Pin. Duration: 10 Glue. SAPolicy. Quota: 0 Glue. SAPolicy. File. Life. Time: permanent Glue. SAState. Available. Space: 16350000000 Glue. SAState. Used. Space: 0 Glue. SAAccess. Control. Base. Rule: cometa Tecnologia dei Servizi “Grid e cloud computing” - Lezione 8 24
GLUE: Access Protocols Glue. SEAccess. Protocol. Local. ID: gsiftp Glue. SEAccess. Protocol. Type: gsiftp Glue. SEAccess. Protocol. Endpoint: gsiftp: //infn-se-01. ct. trigrid. it Glue. SEAccess. Protocol. Capability: file transfer Glue. SEAccess. Protocol. Version: 1. 0. 0 Glue. SEAccess. Protocol. Port: 2811 Glue. SEAccess. Protocol. Supported. Security: GSI Glue. SEAccess. Protocol. Local. ID: rfio Glue. SEAccess. Protocol. Type: rfio Glue. SEAccess. Protocol. Endpoint: httpg: //infn-se-01. ct. trigrid. it Glue. SEAccess. Protocol. Capability: byte access Glue. SEAccess. Protocol. Version: 1. 0. 0 Glue. SEAccess. Protocol. Port: 5001 Glue. SEAccess. Protocol. Supported. Security: RFIO Tecnologia dei Servizi “Grid e cloud computing” - Lezione 8 25
LCG Information System Tecnologia dei Servizi “Grid e cloud computing” - Lezione 8 26
LCG Information System p LCG adopted a combination of solutions (now only BDII). n Globus MDS p p n BDII p p p At the lowest level of the information system To discover and monitor resources and publish information Grid Information Security (GSI) credentials Caching At the highest level of the system Because MDS had some troubles in terms of scalability Used by the Resource Broker for the matchmaking process Can be configured by each VO Queries underlying systems periodically (2 minutes) Hierarchical system n n n Information is collected on the leaves of a hierarchical tree and travels towards the root Clients can query the hierarchical tree at every level The higher the level against which queries are made, the older is the obtained information Tecnologia dei Servizi “Grid e cloud computing” - Lezione 8 27
Collecting Information p Gathering of information at different levels n Lower level: Grid Resource Information Server (GRIS) p p p n Medium level: Grid Index Information Server (GIIS) p p n Collects information on the state of a given resource One GRIS on top of each resource A set of scripts and sensor that try to extract useful info on the resource Collects information on resources of a given site One GIIS for each site Higher level: BDII p p Collects information on resources of a given VO One BDII for each VO (suggested solution) NOW all levels are based on BDII p Way of collecting info n n Pull model (higher level servers periodically query lower level servers) LDAP query model Tecnologia dei Servizi “Grid e cloud computing” - Lezione 8 28
BDII overview p The Berkley Database Information Index (BDII) n n n n p Developed within the context of LCG project Solves problems of instability of the MDS occurring when the number of sites grows too much Stays on top of BDII sites One for each VO Centralized system Three levels of hierarchy Accessed by the Workload Management System Way of working n n n One BDII for each resource One BDII for each site collecting info from below BDII systems One BDII for a given VO collecting information from below BDII systems Two LDAP servers, one for write access and one for read access Every two minutes a cron-job runs a script and collects info from a list of BDII sites The list of site BDII is placed in the configuration file of the top BDII Tecnologia dei Servizi “Grid e cloud computing” - Lezione 8 30
LCG Information System Hierarchy today Tecnologia dei Servizi “Grid e cloud computing” - Lezione 8 31
Information & Monitoring Services Berkeley Database Information Index BDII top-level Queries WMS 2 minutes BDII site-level Site WN UI FTS BDII resource MDS GRIS provider Tecnologia dei Servizi “Grid e cloud computing” - Lezione 8 - Based on ldap - Standardized information provider (GIP) - GLUE-1. 3 schema - Top level Used with 230+ sites - Roughly 60 instances in EGEE 32
BDII overview p Every node (except UI and WNs) has a bdii service in order to publish its informations p A node in every site collects all site BDIIs and publishes them using a site BDII; p The top BDII collects all site BDIIs p User can run a set of commands to query the top BDII. Tecnologia dei Servizi “Grid e cloud computing” - Lezione 8 33
Top BDII vs Site BDII p p Site BDII n It collects all grid BDIIs (for example SE, RB, LFC, etc. . ) n The name of the service is bdii Top BDII n It collects all site BDIIs* ; n The name of the service is bdii n It gives to the RB/WMS all needed informations to match and dispatch user's jobs n It can run in the same machine where the RB/WMS is running (it's more fast in answer) *BDII=Berkely Database Infomatin Index Tecnologia dei Servizi “Grid e cloud computing” - Lezione 8 34
References p g. Lite doc http: //glite. web. cern. ch/glite/documentation/default. asp n p g. Lite user. Guide https: //edms. cern. ch/file/722398//g. Lite-3 -User. Guide. pdf EGEE: The Information System https: //twiki. cern. ch/twiki/bin/view/EGEE/Information. System. Overview n n Berkeley Database Information Index V 5 https: //twiki. cern. ch/twiki/bin/view/EGEE/BDII Glue Usage within EGEE https: //twiki. cern. ch/twiki/bin/view/EGEE/Glue. Use What is LDAP? http: //www. openldap. org/doc/admin 22/intro. html#What%20 is%20 LDAP Usage of Glue Schema v 1. 3 for WLCG Installed Capacity information: https: //twiki. cern. ch/twiki/pub/LCG/WLCGCommon. Computing. Readiness. Challeng es/WLCG_Glue. Schema. Usage-1. 8. pdf Tecnologia dei Servizi “Grid e cloud computing” - Lezione 8 35
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