Introduction to Globus with Condor-G

1. Israel Academic Grid (IAG) Introduction to Globus with Condor-G Itzhak Ben Akiva (TAU) David Front (WI) Globus with Condor-G

2. Agenda • Grid security and certificates • Globus • Condor-G • Condor-G submission examples • References Globus with Condor-G

3. Grid Security Infrastructure (GSI) • GSI is a set of tools, libraries and protocols used in Globus to allow users and applications to securely access resources. • Based on a public key infrastructure, with certificate authorities and X509 certificates Proxies and delegation for secure single Sign-on Proxies and Delegation SSL/ TLS PKI (CAs and Certificates) SSL for Authentication And message protection PKI for credentials Globus with Condor-G

4. Owner Public Key Infrastructure (PKI) • PKI allows you to know that a given public key belongs to a given user • PKI builds off of asymmetric encryption: • Each entity has two keys: public and private • Data encrypted with one key can only be decrypted with other. • The private key is known only to the entity • The public key is given to the world encapsulated in a X.509 certificate Globus with Condor-G

5. Name Issuer Public Key Signature John Doe 755 E. Woodlawn Urbana IL 61801 State of Illinois Seal BD 08-06-65 Male 6’0” 200lbs Certificates • Certificates link between public key & identity of a: • Person, organization, or device (“subject”) • Associated with use of private key • Used by a “relying party” • Certificate Authority (CA) are responsible for establishing identity • CA generates key pair, and digitally signs the public key making it a Certificate Globus with Condor-G

6. Certificates: what CA to use? The following possibilities go from the less secure to the most secure: • Anyone can become a certificate authority: http://www.onlamp.com/pub/a/onlamp/2003/02/06/linuxhacks.html • Free certificate authorities: • http://www.thawte.com/ • http://www.verisign.com/ ... • Globus CA:http://www-fp.globus.org/gt2.4/admin/guide-verify.html#certcoerces some security limitations such as: • Domain of host to get a certificate should be the same as requestor’s email domain • EDG CA: http://igc.services.cnrs.fr/Datagrid-fr/english/index.htmlEDG does not honor Globus certificates.EDG Grants certificates only to people that are known personally by an authorized third person. For each non-Globus CA, each site should configure the CA as being a trusted one. Globus is trusted by default and EDG has RPMs for adding it as a trusted CA. Recommendation: until Machba supplies certificates, use Globus CA. Globus with Condor-G

7. Globus with Condor-G. A resource broker to be added later Globus with Condor-G

8. Globus Gurus: • Ian Foster • Carl Kesselman Globus Project™ • www.globus.org Globus is a bag of tools Grid SW projects use Globus Globus with Condor-G

9. What is Globus? • A research and development project that enables the application of Grid concepts to scientific and engineering computing. • Globus Toolkit allows: build Grids, develop Grid applications • Globus Project research targets technical challenges and Globus Toolkit supplies a set of services and software libraries to support Grids and Grid applications: • (GRAM) resource management • (GSI) security • (MDS) information infrastructure • (GASS) data management • (HBM) fault detection • (Nexus and globus_io) portability + communication Globus with Condor-G

10. The Globus Toolkit contents • A “bag of services”: components to develop grid applications + programming tools • Component have a C application programmer interface (API) • Some Components have Java classes and/or command line tools • Prototypes of • higher components (resource brokers, co-allocators) • and services. • Others use the Globus Toolkit to develop: • higher-level services, • application frameworks, • and scientific/engineering applications Example: • Condor-G uses Globus for its high-throughput computing framework Globus with Condor-G

11. Globus Toolkit: GRAM + GSI • Globus Resource Allocation Manager (GRAM) • Resource allocation • Process creation • Monitoring • Management • Maps requests expressed in a Resource Specification Language (RSL) into commands to local schedulers and computers. • Grid Security Infrastructure (GSI) • A single-sign-on, run-anywhere authentication service, • local control over access rights • mapping from global to local user identities. • Smartcard support increases credential security. Globus with Condor-G

12. Globus Toolkit: MDS + GASS • Monitoring and Discovery Service (MDS): • Extensible Grid information service • Combines data discovery mechanisms with the Lightweight Directory Access Protocol (LDAP). • Uniform framework for providing and accessing system configuration and status information, such as: • Compute server configuration • Network status, • Locations of replicated datasets • Global Access to Secondary Storage (GASS): • Implements a variety of automatic and programmer-managed data movement and data access strategies • Enables remote programs to read and write local data. Globus with Condor-G

13. Globus Toolkit: Nexus,globus_io, HBM, GPT • Nexus and globus_io: communication services for heterogeneous environments: • multimethod communication • multithreading • single-sided operations • The Heartbeat Monitor (HBM): Allows system administrators or ordinary users to • detect failure of system components • detect failure of application processes • Globus Packaging Tool: (GPT): • VDT’s Packman installs Globus and Condor-G.Hence, is it more appropriate for Condor-G users. Globus with Condor-G

14. Application Application Internet Protocol Architecture “Coordinating multiple resources”: ubiquitous infrastructure services, app-specific distributed services Collective “Sharing single resources”: negotiating access, controlling use Resource “Talking to things”: communication (Internet protocols) & security Connectivity Transport Internet “Controlling things locally”: Access to, & control of, resources Fabric Link Layered Grid Architecture(By Analogy to Internet Architecture) Globus with Condor-G

15. MDS-2 (Monitor./Discov. Svc.) Soft state registration; enquiry Reliable remote invocation GSI (Grid Security Infrastruc-ture) User Reporter(registry +discovery) GIIS: GridInformationIndex Server (discovery) Gatekeeper(factory) Authenticate & create proxy credential Other GSI-authenticated remote service requests Create process Register User User process #1 process #2 Other service(e.g. GridFTP) Proxy Proxy #2 GRAM (Grid Resource Allocation & Management) The Globus Toolkit in One Slide Grid protocols (GSI, GRAM, …) enable resource sharing within virtual orgs; toolkit provides reference implementation ( = Globus Toolkit services) Protocols (and APIs) are central to Globus toolkit Globus with Condor-G

16. Globus Toolkit: missing, weak, plans 1 • (GRAM) resource management • Condor-G adds: reliable job submission • (EDG) Resource broker: choose Globus resource to submit job • Globus plans: support end-to-end performance management and fault tolerance via network scheduling, advance reservations, and policy-based authorization. • (GSI) security Using X.509 certificates has various limitations. For example: • If a user does not use a pass phrase, anyone that puts a hand on her certificate can use it. • (MDS) information infrastructure • LDAP: too weak for frequently changing information (EDG uses RDBM instead of LDAP) Globus with Condor-G

17. Globus Toolkit: missing, weak, plans 2 • (GASS) data management • Globus current replica management capabilities are limited • Globus plans: provide high-performance access to large amounts of data (terabytes or petabytes). • (HBM) fault detection • (Nexus and globus_io) portability + communication • Others • Weak accounting • ‘The firewall problem’: In order to submit a Globus job, some Internet ports should be opened. This is a security problem. • Weak fabric tools: • Installation/configuration: • VDT adds configurable installation via Packman • EDG adds Client-server installation + updating via LCFG • Weak monitoring tools • Restricted support for Windows. Globus with Condor-G

18. Globus support for Windows • Port of the Globus Toolkit to the Windows XP/2000 platform is under development/test. • Using Grid resources from Windows systems or turn Windows systems into Grid resources: • The Java CoG Kit (http://www.globus.org/cog/) provides access to Grid services via the Java programming language, available on Windows. • A Java-based GRAM service is currently being developed. • The Condor software from the Condor Project at the University of Wisconsin (http://www.cs.wisc.edu/condor/) provides job management services that allow you to submit jobs to a local service that then submits your jobs to remote resources for execution. Condor can use Grid resources to execute these jobs. Condor is available for Windows. Globus with Condor-G

19. Job manager Job manager Globus toolkit (re)structure Service naming Soft state management Reliable invocation GRAM MDS GridFTP MDS ??? Notification GSI GSI GSI Other Service or Application Compute Resource Data Resource Lots of good mechanisms, but (with the exception of GSI) not that easily incorporated into other systems Globus with Condor-G

20. Find Publish Bind Service Oriented Architecture (SOA) • New buzzwords: • Services (in addition to protocols and APIs) • Open Grid Services Architecture (OGSA) • Web services • Soap • XML Service Registry Service Requestor Service Provider OGSA may become standard Globus with Condor-G

21. GridService (required) … other interfaces … (optional) Service data query Explicit destruction Soft-state lifetime • Standard: • - Notification • - Service creation • - Service registry • Authorization • Manageability • + application-specific interfaces The Grid Service =Interfaces/Behaviors + Service Data Service data element Service data element Service data element Binding properties: - Reliable invocation - Authentication Implementation Hosting environment/runtime (“C”, J2EE, .NET, …) Globus with Condor-G

22. Condor-G Guru: • Miron Livny Condor Project: • http://www.cs.wisc.edu/condor Condor-G manual: • http://www.cs.wisc.edu/condor/manual/v6.4/5_2Condor_G.html Condor is a scheduler, similar to PBS, LSF and others Condor-G is (the submission) part of Condor. It adds to Globus Reliable job submission Globus with Condor-G

23. Condor-G from Globus eyes • Condor-G adds to Globus reliable job submission. It lets you: • Submit jobs into a queue • have a log detailing the life cycle of your jobs • manage your input and output files • along with everything else you expect from a job queuing system. • Condor-G does more than Globus toolkit's globusrun command: • It allows you to submit many jobs at once • and then to monitor those jobs with a convenient interface • receive notification when jobs complete or fail • maintain your Globus credentials which may expire while a job runs • Condor-G is a fault-tolerant system:If your machine crashes, you can still perform all of these functions when your machine returns to life. Globus with Condor-G

24. Condor-G from Condor eyes • Condor-G is a Globus-enabled version of the Condor scheduler.It uses Globus to handle inter-organizational problems like: • Security • Resource management for supercomputers, • Executable staging. Hence: The same Condor tools that access local resources are now able to use the Globus protocols to access resources at multiple sites. • Condor-G manages both a queue of jobs and the resources from one or more sites where those jobs can execute. It communicates with these resources and transfers files to and from these resources using Globus mechanisms, such as: • GSI • GRAM protocol for job submission, • and a local GASS server for file transfers. • The mutual look: Condor can be used to submit jobs to systems managed by Globus. Globus tools can be used to submit jobs to systems managed by Condor. Globus with Condor-G

25. how Condor-G interacts with Globus protocols Figure 5.1: Remote Execution by Condor-G on Globus managed resources Globus with Condor-G

26. Submitting a job to Condor-G: example 1 Run your compiled program on a different Globus resource: • Make sure your Condor server service is running on the Condor server. (Not explained here) • Make sure you have your Grid credentials, create a proxy:grid-proxy-init • To submit a job: condor_ submit < submit-description-file-name> • The following sample runs a job on the Origin2000 at NCSA: executable = test globusscheduler = modi4.ncsa.uiuc.edu/jobmanager universe = globus output = test.out log = test.log queue • The executable for this example is transferred from the local machine to the remote machine. • By default, Condor transfers the executable, as well as any files specified by the input command. • This executable must be compiled for the correct intended platform. Globus with Condor-G

27. Submitting a job to Condor-G example 1 cont. • The globusscheduler command is dependent on the scheduling software available on remote resource. This required command will change based on the Grid resource intended for execution of the job. • All Condor-G jobs are submitted to the globus universe. Hence:universe= globusis always required in the submit description file. • IO:No input file is specified for this example job. Any output (file specified by the output) or error (file specified by the error) is transferred from the remote machine to the local machine as it is produced. This implies that these files may be incomplete in the case where the executable does not finish running on the remote resource. The job log file is maintained on the local machine. • To submit this job to Condor-G for execution on the remote machine, use: condor_submit test.submitwhere test.submit is the name of the submit description file. Globus with Condor-G

28. Submitting a job to Condor-G example 1 cont. Example output from condor_ q for this submission looks like: % condor_q -- Submitter: wireless48.cs.wisc.edu : <128.105.48.148:33012> : wireless48.cs.wi ID OWNER SUBMITTED RUN_TIME ST PRI SIZE CMD 7.0 epaulson 3/26 14:08 0+00:00:00 I 0 0.0 test 1 jobs; 1 idle, 0 running, 0 held After a short time, Globus accepts the job. Again running condor_ q will now result in % condor_q -- Submitter: wireless48.cs.wisc.edu : <128.105.48.148:33012> : wireless48.cs.wi ID OWNER SUBMITTED RUN_TIME ST PRI SIZE CMD 7.0 epaulson 3/26 14:08 0+00:01:15 R 0 0.0 test 1 jobs; 0 idle, 1 running, 0 held Then, very shortly after that, the queue will be empty again, because the job has finished: % condor_q -- Submitter: wireless48.cs.wisc.edu : <128.105.48.148:33012> : wireless48.cs.wi ID OWNER SUBMITTED RUN_TIME ST PRI SIZE CMD 0 jobs; 0 idle, 0 running, 0 held Globus with Condor-G

29. Submitting a job to Condor-G example 2 Run the (prestaged) Unix ls program on a different Globus resource: executable = /bin/ls Transfer_Executable = false globusscheduler = vulture.cs.wisc.edu/jobmanager universe = globus output = ls-test.out log = ls-test.log queue • The executable is pre-staged. Being on the remote machine, there is no need to transfer it before execution. • The required globusscheduler and universe commands are present. • The command Transfer_Executable = FALSE identifies the executable as being pre-staged. In this case, the executable command gives the path to the executable on the remote machine. Globus with Condor-G

30. Submitting a job to Condor-G example 3 Submit a Perl script to be run as a Condor job. The Perl script both lists and sets environment variables for a job. • Save the following Perl script with the name env-test.pl, to be used as a Condor job executable: #!/usr/bin/env perl foreach $key (sort keys(%ENV)) { print "$key = $ENV{$key}\n" } exit 0; • Run the Unix command chmod 755 env-test.pl to make the Perl script executable. • Create the following submit description file executable = env-test.pl globusscheduler = biron.cs.wisc.edu/jobmanager universe = globus environment = foo=bar; zot=qux output = env-test.out log = env-test.log queue Globus with Condor-G

31. Submitting a job to Condor-G example 3 cont. • When the job has completed, the output file env-test.out should contain something like this: GLOBUS_GRAM_JOB_CONTACT = https://biron.cs.wisc.edu:36213/30905/1020633947/ GLOBUS_GRAM_MYJOB_CONTACT = URLx-nexus://biron.cs.wisc.edu:36214 GLOBUS_LOCATION = /usr/local/globus GLOBUS_REMOTE_IO_URL = /home/epaulson/.globus/.gass_cache/globus_gass_cache_1020633948 HOME = /home/epaulson LANG = en_US LOGNAME = epaulson X509_USER_PROXY = /home/epaulson/.globus/.gass_cache/globus_gass_cache_1020633951 foo = bar zot = qux Globus with Condor-G

32. Submitting a job to Condor-G example 3 cont. Of particular interest is GLOBUS_REMOTE_IO_URL environment variable: Condor-G automatically starts up a GASS remote I/O server on the submitting machine. Because of the potential for either side of the connection to fail, the URL for the server cannot be passed directly to the job. Instead, it is put into a file, and the GLOBUS_REMOTE_IO_URL environment variable points to this file. Remote jobs can read this file and use the URL it contains to access the remote GASS server running inside Condor-G. If the location of the GASS server changes (for example, if Condor-G restarts), Condor-G will contact the Globus gatekeeper and update this file on the machine where the job is running. It is therefore important that all accesses to the remote GASS server check this file for the latest location. Globus with Condor-G

33. Submitting a job to Condor-G last example A Perl script that uses the GASS server in Condor-G to copy input files to the execute machine. (the remote job counts the number of lines in a file.) #!/usr/bin/env perl use FileHandle; use Cwd; STDOUT->autoflush(); $gassUrl = `cat $ENV{GLOBUS_REMOTE_IO_URL}`; chomp $gassUrl; $ENV{LD_LIBRARY_PATH} = $ENV{GLOBUS_LOCATION}. "/lib"; $urlCopy = $ENV{GLOBUS_LOCATION}."/bin/globus-url-copy"; # globus-url-copy needs a full pathname $pwd = getcwd(); print "$urlCopy $gassUrl/etc/hosts file://$pwd/temporary.hosts\n\n"; `$urlCopy $gassUrl/etc/hosts file://$pwd/temporary.hosts`; open(file, "temporary.hosts"); while(<file>) { print $_; } exit 0; Globus with Condor-G

34. Submitting a job to Condor-G last example Cont. • The submit file: executable = gass-example.pl globusscheduler = biron.cs.wisc.edu/jobmanager universe = globus output = gass.out log = gass.log queue • There are two optional submit description file commands of note: x509userproxy and globusrsl. 1) The x509userproxy command specifies the path to an X.509 proxy, as: x509userproxy = /path/to/proxy • If this optional command is not present in the submit description file,then Condor-G checks the value of the environment variable X509_USER_PROXY for the location of the proxy. • If this environment variable is not present, then Condor-G looks for the proxy in the file /tmp/x509up_u0000, where the trailing zeros in this file name are replaced with the Unix user id. Globus with Condor-G

35. Submitting a job to Condor-G last example Cont. 2)The globusrsl command is used to add additional attribute settings to a job's RSL string, as: globusrsl = (name=value)(name=value) An example of this command in a submit description file globusrsl = (project=Test_Project) This example's attribute name for the additional RSL is project, and the value assigned is Test_Project. Globus with Condor-G

36. Limitations of Condor-G • No checkpoints. • No matchmaking. • File transfer is limited. There are no file transfer mechanisms for files other than the executable, stdin, stdout, and stderr. • No job exit codes. Job exit codes are not available. • Limited platform availability. Condor-G is only available on Linux, Solaris, Digital UNIX, and IRIX. HP-UX support will hopefully be available later. Globus with Condor-G

37. References • Globus Project www.globus.org • Overviews of Grid computing: Anatomy of the grid: http://www-fp.globus.org/research/papers.html#anatomy Physiology of the grid:http://www-fp.globus.org/research/papers.html#OGSA Older, extensive: The Grid: Blueprint for a New Computing Infrastructure, I. Foster and C. Kesselman (Eds), Morgan Kaufmann, 1999. • Globus FAQhttp://www-fp.globus.org/about/faq/general.html • Globus installationhttp://www-fp.globus.org/gt2/admin/guide-verify.html • Condor-G manual:http://www.cs.wisc.edu/condor/manual/v6.4/5_2Condor_G.html • A topical school on Grid computing will be held in Vico Equense, Italy during the last two weeks of July, 2003.For details, send an email togrid-chool@ggf.org. • Global Grid Forum www.gridforum.org Globus with Condor-G