gLite Overview

1. gLite Overview Richard Miguel San Martin SENAMHI - PERU La Antigua, 18 – 19 October 2007

2. Disclaimer • This presentation is based on materials provided and authorized by the EGEE project and EELA project. It is freely available to download and use.

3. Overview • Introduction • Grid Concepts • gLite • Architecture by services • Architecture by machines • Life of Jobs

4. Introduction • gLite is a complex system, composed of various packages installed on different machines, interacting with each other and every of them playing a different role in the chain of the grid activity. • It can be deployed and configured in extremely variable number of ways, because of its modularity and scalability, and it relies as last part of its chain on Local Batch System such as PBS/TORQUE-MAUI, LSF and Condor.

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

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

7. gLite • gLite is the next generation middleware for grid computing. • Born from the collaborative efforts from academic and industrial research centers as part of the EGEE Project. • The gLite Grid services follow a Service Oriented Architecture • facilitate interoperability among Grid services • allow easier compliance with upcoming standards • Architecture is not bound to specific implementations • services are expected to work together • services can be deployed and used independently • The gLite service decomposition has been largely influenced by the work performed in the LCG project

8. Building on GSI • Build on Grid Security Infrastructure to create services that include: • Job submission: run a job on a remote computer • Information services: So I know which computer to use • File transfer: so large data files can be transferred • Replica management: so I can have multiple versions of a file “close” to the computers where I want to run jobs • Production grids are (currently) based on the Globus Toolkit release 2 Globus Alliance: http://www.globus.org/

9. gLite - Middleware • Many VOs need sharing of resources through services • Accessing • Allocating • Monitoring • Accounting • gLite – Lightweight Middleware for Grid Computing

10. gLite – Service Decomposition 5 High level services + CLI & API

11. gLite – Security Services

12. gLite –Security ServicesAuthentication • 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)

13. Authentication User receives certificate signed by CA Connects to “UI” by ssh Downloads certificate Single logon to Grid – create proxy - then Grid Security Infrastructure identifies user to other machines Authorisation User joins Virtual Organisation VO negotiates access to Grid nodes and resources Authorisation tested by CE gridmapfile maps user to local account UI gLite –Security ServicesAuthentication - Authorization Personal/once 2. AUP 3. VO mgr VO service VO database GSI

14. gLite – Security ServicesAuditing, Delegation, Sandboxing Auditing - Monitoring and Post-Mortem analysis of security related events. In computational grids It goes hand by hand with the accounting. • Who did what? • Where and when? • Delegation: The need of delegate privileges to other entities is done by ProxyCertificates. This is the most widely adopted mechanism by Grid communities. (Also: Single Sign-On, Dynamic entity identification). • Sandboxing - Grid applications need the isolation of assigned resources in a transparent fashion by Security services: AuthN and AuthZ. (Virtualisation).

15. gLite – Grid Access Two possibilities: APIs and CLI. The use of web-services allows the automatic generation of APIs.

16. gLite – Information and Monitoring Services Information services are vital low level component of Grids.

17. gLite – Information and Monitoring ServicesBasic info and monitoring services (RGMA) • Information is provided by a Publish and Consume mechanism. • Appearance of a single federated database to query through the SQL. • Each VO has a VDB. • Schema - Contains tables (GLUE) • Registry – List of available sources of information (Mediation) • Producers – Source of information (Primary, Secondary, On-demand) • Consumers – Make queries against tables (Continuous, Latest, History)

18. gLite – Information and Monitoring ServicesJob Monitoring, Service Discovery, Network performance Monitoring • Job Monitoring – Java logging service, log4j, Apache/Chainsaw (for other languages). • Service Discovery – Locates suitable services to both users and services. • Network Performance Monitoring – Many network monitoring frameworks. Aim: perform a standard interface to those frameworks.

19. gLite – Job Management Services

20. gLite – Job Management ServicesAccounting • Accumulates information about the resource usage done by users or groups of users (VOs). • Information on Grid Services/Resources needs sensors (Resource Metering, Metering Abstraction Layer, Usage Records). • Records are collected by the Accounting System (Queries: Users, Groups, Resource) • Grid services should register themselves with a pricing service when accounting for billing purposes.

21. gLite – Job Management ServicesComputing Element • Service that represent the computing resource that is responsible of the job management: (submission, control, etc.) • CEs refer to a set or a cluster of computational resources (WN) managed by LRMS, to dispatch jobs matching users requests. • Two job submission models (accordingly to user requests and site policies): • PUSH (jobs pushed to CE queue), • PULL (jobs coming from WMS when CE queue is empty) • CE responsible to collect accounting information.

22. Computing Element (CE) CEA … Computing Element Acceptance JC … Job Controller MON … Monitoring LRMS … Local Resource Management System

23. gLite – Job Management ServicesWorkload Management • WMS set of middleware components responsible of distribution and management of jobs across Grid resources. • Two core components of WMS: • WM: accept and satisfyrequests for job management.Matchmaking is the process of assigning the best available resource. • L&B: keeptrack of job execution in term of events: (Submitted, Running, Done,...)

24. gLite – Job Management ServicesJob Provenance, Package Manager • Job Provenance (JP) - Keeps track of submitted jobs for long periods (months, years). • Package Manager – Helper service to automate: installing, configuring, updating and removing of software components. (RPM, dpkg/APT, Portage, …)

25. gLite – Data Services

26. gLite – Data ServicesStorage Element Needed Service are at least: • Storage back-end (Drivers and Hardware) • SRM Interface (Storage Specific) • Transfer service (GridFTP) • Native POSIX like file I/O API (gLite-I/O) • Auxiliary Accounting and Logging services

27. gLite – Data ServicesData Movement • Data Scheduler (DS) Keep track of user/service transfer requests • File Transfer/Placement Service (FTS/FPS) • Transfer Queue (Table) • Transfer Agent (Network)

28. gLite – Helper Services Configuration and Instrumentation Service – Query service state. Agreement Service – Implements a communication protocol for the SLAs. Bandwidth Allocation & Reservation service (BAR) – Controlling, Balancing and Manage Network flows.

29. VOMS • Virtual Organization Membership Service • Multiple VOs • Multiple roles in VO • Compatible X509 extensions • Signed by VOMS server • Web admin interface • Supports MyProxy • Resources providers grant access to VOs or roles • Sites map VO members/roles to local auth mechanism (unix users accounts) • Allows for local policy

30. MyProxy • MyProxy • Allows longer lived jobs / increases security • WMS renews proxy • Users should not produce long lives proxies • Allows for secure user mobility • Users does not need to copy globus-keys around

31. Architecture • User Interface (UI) • Workload management system (WMS) • Logging and bookkeeping service (LB) • Virtual Organization Management service (VOMS) • Information system (BDII, RGMA?), monitoring (MON) • Computing element (CE) and worker nodes (WN) • Storage element (SE) and File catalogue (LFC)

32. Components • The User Interface (UI) is the package on the user's machine. It is the submission entry point of the system, and it is considered a part of the WMS. • The Workload Management System (WMS) is a sum of components whose task is matching the resources requested by the user's job with the ones available on the Computing Elements, in order to find the machine where the job will be executed • The Computing element (CE)is the entry point in the Local Batch Systems of the resources. It can be an executing machine itself or simply the entry point for the local cluster managed by a batch system (PBS,LSF, CONDOR) • The Worker Nodes are the machines on which the job is actually executed. They are linked with the CE through a local batch system, to which at last the jobs are submitted

33. Components • The Information System and Monitoring (IS and MON), which keep data about resources available and the status of the system • The Logging and bookkeeping service (LB), that keeps rack of the events which happen to the jobs (and can be very useful to us bench makers!!) • The Virtual Organization Management service (VOMS) , for Authentication and Authorization. • The Storage element (SE) and File catalogue (LFC), to manage big file transfer or make easier the availability of files jobs need.

34. Life of a Job

35. Questions