Condor J2 + Developer APIs to Condor + A Tutorial on Condor’s Web Service Interface

1. Condor J2+Developer APIs to Condor+A Tutorial on Condor’s Web Service Interface

2. CondorJ2 • Quill/Quill++: Database reflects state of Condor pool • Condor J2: Database is the state of Condor pool • Overview of CondorJ2 • Use database to maintain operational data (workflow state, machine state, config policies, etc.) • Implement workflow management, resource management and resource allocation in J2EE Application Server environment • Modify master, startd and starter to be web service clients • Provide web interface for all system services (workflow submission, machine reconfiguration etc.)

3. Motivation • Flexibility • Centralized Administratibility • Attempt to leverage standard “enterprise” technology in this space • Scalability • As big as you want if you are willing to pay the big $$$

4. Java Application Servers • Industrial strength middleware for high performance & scalable web applications • Widely deployed systems • Oracle AS 10g, IBM WebSphere, BEA WebLogic, JBoss (open source) • Key features • Database connection pooling • Support for transactions • Web service interfaces • Support for clustering (for scalability) • Pluggable security models / role based authorization • Backend database independence

5. Condor Database JDBC Application Server Machine Modules Matchmaking Modules Workflow Modules Condor Pool Web Site Condor Web Services HTTP SOAP over HTTP User’s Web Browser User’s Custom Tools master startd starter Web Service Clients Execute Machines

6. Pool Database JDBC Application Server Application Server Application Server Load Balancer Firewall NAT SOAP over HTTP startd startd startd starter starter starter job job job Execute Machines

7. What can do in CondorJ2 via browsers and web services? • Where do we stand now? • Add and configure new machines • Reconfigure machines on the fly • Specify, submit, monitor and manage workflows • Monitor global system state • No matchmaking (yet) • Is currently research work. When will it ship? Will it ever ship? Only time will tell.

8. Interfacing Applications w/ Condor • Suppose you have an application which needs a lot of compute cycles • You want this application to utilize a pool of machines • How can this be done?

9. Some Condor APIs • MW (previous talk) • Command Line tools • condor_submit, condor_q, etc • DRMAA • Condor GAHP • Condor Perl Module • SOAP

10. Command Line Tools • Don’t underestimate them! • Your program can create a submit file on disk and simply invoke condor_submit: system(“echo universe=VANILLA > /tmp/condor.sub”); system(“echo executable=myprog >> /tmp/condor.sub”); . . . system(“echo queue >> /tmp/condor.sub”); system(“condor_submit /tmp/condor.sub”);

11. Command Line Tools • Your program can create a submit file and give it to condor_submit through stdin: PERL: fopen(SUBMIT, “|condor_submit”); print SUBMIT “universe=VANILLA\n”; . . . C/C++: int s = popen(“condor_submit”, “r+”); write(s, “universe=VANILLA\n”, 17/*len*/); . . .

12. Command Line Tools • Using the +Attribute with condor_submit: universe = VANILLA executable = /bin/hostname output = job.out log = job.log +webuser = “zmiller” queue

13. Command Line Tools • Use -constraint and –format with condor_q: % condor_q -constraint ‘webuser==“zmiller”’ -- Submitter: bio.cs.wisc.edu : <128.105.147.96:37866> : bio.cs.wisc.edu ID OWNER SUBMITTED RUN_TIME ST PRI SIZE CMD 213503.0 zmiller 10/11 06:00 0+00:00:00 I 0 0.0 hostname % condor_q -constraint 'webuser=="zmiller"' -format "%i\t" ClusterId -format "%s\n" Cmd 213503 /bin/hostname

14. Command Line Tools • condor_wait will watch a job log file and wait for a certain (or all) jobs to complete: system(“condor_wait job.log”); • can specify a timeout

15. Command Line Tools • condor_q and condor_status –xml option • So it is relatively simple to build on top of Condor’s command line tools alone, and can be accessed from many different languages (C, PERL, python, PHP, etc). • However…

16. DRMAA • DRMAA is a GGF standardized job-submission API • Has C (and now Java) bindings • Is not Condor-specific -- your app could submit to any job scheduler with minimal changes (probably just linking in a different library) • SourceForge Project http://sourceforge.net/projects/condor-ext

17. DRMAA • Easy to use, but • Unfortunately, the DRMAA API does not support some very important features, such as: • Two-phase commit • Fault tolerance • Transactions

18. Condor GAHP • The Condor GAHP is a relatively low-level protocol based on simple ASCII messages through stdin and stdout • Supports a rich feature set including two-phase commits, transactions, and optional asynchronous notification of events • Is available in Condor 6.7.X

19. GAHP, cont Example: R: $GahpVersion: 1.0.0 Nov 26 2001 NCSA\ CoG\ Gahpd $ S: GRAM_PING 100 vulture.cs.wisc.edu/fork R: E S: RESULTS R: E S: COMMANDS R: S COMMANDS GRAM_JOB_CANCEL GRAM_JOB_REQUEST GRAM_JOB_SIGNAL GRAM_JOB_STATUS GRAM_PING INITIALIZE_FROM_FILE QUIT RESULTS VERSION S: VERSION R: S $GahpVersion: 1.0.0 Nov 26 2001 NCSA\ CoG\ Gahpd $ S: INITIALIZE_FROM_FILE /tmp/grid_proxy_554523.txt R: S S: GRAM_PING 100 vulture.cs.wisc.edu/fork R: S S: RESULTS R: S 0 S: RESULTS R: S 1 R: 100 0 S: QUIT R: S

20. Condor Perl Module • Perl module to parse the “job log file” • Recommended instead of polling w/ condor_q • Call-back event model • (Note: job log can be written in XML)

21. SOAP • Simple Object Access Protocol • Mechanism for doing RPC using XML (typically over HTTP or HTTPS) • A World Wide Web Consortium (W3C) standard • SOAP Toolkit: Transform a WSDL to a client library

22. Benefits of a Condor SOAP API • Condor becomes a service • Can be accessed with standard web service tools • Condor accessible from platforms where its command-line tools are not supported • Talk to Condor with your favorite language and SOAP toolkit

23. Condor SOAP API functionality • Submit jobs • Retrieve job output • Remove/hold/release jobs • Query machine status • Query job status

24. SOAP over HTTP Getting machine status via SOAP Your program condor_collector queryStartdAds() Machine List SOAP library

25. Lets get some details…

26. The API • Core API, described with WSDL, is designed to be as flexible as possible • File transfer is done in chunks • Transactions are explicit • Wrapper libraries aim to make common tasks as simple as possible • Currently in Java and C# • Expose an object-oriented interface

27. Condor setup • Start with a working condor_config • The SOAP interface is off by default • Turn it on by adding ENABLE_SOAP=TRUE • Access to the SOAP interface is denied by default • Set ALLOW_SOAP and DENY_SOAP, they work like ALLOW_READ/WRITE/… • See section 3.7.4 of the v6.7 manual for a description • Example: ALLOW_SOAP=*/*.cs.wisc.edu • If using HTTP, must set QUEUE_ALL_USERS_TRUSTED=TRUE • (not needed/wanted with HTTPS)

28. Necessary tools • You need a SOAP toolkit • Apache Axis (Java) - http://ws.apache.org/axis/ • Microsoft .Net - http://microsoft.com/net/ • gSOAP (C/C++) - http://gsoap2.sf.net/ • ZSI (Python) - http://pywebsvcs.sf.net/ • SOAP::Lite (Perl) - http://soaplite.com/ • You need Condor’s WSDL files • Find them in lib/webservice/ in your Condor release • Put the two together to generate a client library • $ java org.apache.axis.wsdl.WSDL2Java condorSchedd.wsdl • Compile that client library • $ javac condor/*.java All our examples are in Java using Apache Axis

29. Helpful tools • The core API has some complex spots • A wrapper library is available in Java and C# • Makes the API a bit easier to use (e.g. simpler file transfer & job ad submission) • Makes the API more OO, no need to remember and pass around transaction ids • We are going to use the Java wrapper library for our examples • You can download it from http://www.cs.wisc.edu/condor/birdbath/birdbath.jar • Will be included in Condor release

30. Explicit bits Implicit bits Submitting a job • The CLI way… cp.sub: universe = vanilla executable = /bin/cp arguments = cp.sub cp.worked should_transfer_files = yes transfer_input_files = cp.sub when_to_transfer_output = on_exit queue 1 clusterid = X procid = Y owner = matt requirements = Z $ condor_submit cp.sub

31. Submitting a job • The SOAP way… • Begin transaction • Create cluster • Create job • Send files • Describe job • Commit transaction Repeat to submit multiple clusters Repeat to submit multiple jobs in a single cluster

32. 1. Begin transaction 2. Create cluster 3. Create job 4&5. Send files & describe job 6. Commit transaction Submission from Java Schedd schedd = new Schedd(“http://…”); Transaction xact = schedd.createTransaction(); xact.begin(30); int cluster = xact.createCluster(); int job = xact.createJob(cluster); File[] files = { new File(“cp.sub”) }; xact.submit(cluster, job, “owner”, UniverseType.VANILLA, “/bin/cp”, “cp.sub cp.worked”, “requirements”, null, files); xact.commit();

33. Schedd’s location Max time between calls (seconds) Job owner, e.g. “matt” Requirements, e.g. “OpSys==\“Linux\”” Extra attributes, e.g. Out=“stdout.txt” or Err=“stderr.txt” Submission from Java Schedd schedd = new Schedd(“http://…”); Transaction xact = schedd.createTransaction(); xact.begin(30); int cluster = xact.createCluster(); int job = xact.createJob(cluster); File[] files = { new File("cp.sub") }; xact.submit(cluster, job, “owner”, UniverseType.VANILLA, “/bin/cp”, “cp.sub cp.worked”, “requirements”, null, files); xact.commit();

34. Querying jobs • The CLI way… $ condor_q -- Submitter: localhost : <127.0.0.1:1234> : localhost ID OWNER SUBMITTED RUN_TIME ST PRI SIZE CMD 1.0 matt 10/27 14:45 0+02:46:42 C 0 1.8 sleep 10000 … 42 jobs; 1 idle, 1 running, 1 held, 1 unexpanded

35. Also, getJobAds given a constraint, e.g. “Owner==\“matt\”” Querying jobs • The SOAP way from Java… String[] statusName = { “”, “Idle”, “Running”, “Removed”, “Completed”, “Held” }; int cluster = 1; int job = 0; Schedd schedd = new Schedd(“http://…”); ClassAd ad = new ClassAd(schedd.getJobAd(cluster, job)); int status = Integer.valueOf(ad.get(“JobStatus”)); System.out.println(“Job is “ + statusName[status]);

36. Retrieving a job • The CLI way.. • Well, if you are submitting to a local Schedd, the Schedd will have all of a job’s output written back for you • If you are doing remote submission you need condor_transfer_data, which takes a constraint and transfers all files in spool directories of matching jobs

37. Discover available files Remote file Local file Retrieving a job • The SOAP way in Java… int cluster = 1; int job = 0; Schedd schedd = new Schedd(“http://…”); Transaction xact = schedd.createTransaction(); xact.begin(30); FileInfo[] files = xact.listSpool(cluster, job); for (FileInfo file : files) { xact.getFile(cluster, job, file.getName(), file.getSize(), new File(file.getName())); } xact.commit();

38. Authentication for SOAP • Authentication is done via mutual SSL authentication • Both the client and server have certificates and identify themselves • Possible in 6.7.20 • It is not always necessary, e.g. in some controlled environments (a portal) where the submitting component is trusted • A necessity in an open environment -- remember that the submit call takes the job’s owner as a parameter

39. Questions?

40. Authentication setup • Create and sign some certificates • Use OpenSSL to create a CA • CA.sh -newca • Create a server cert and password-less key • CA.sh -newreq && CA.sh -sign • mv newcert.pem server-cert.pem • openssl rsa -in newreq.pem -out server-key.pem • Create a client cert and key • CA.sh -newreq && CA.sh -sign && mv newcert.pem client-cert.pem && mv newreq.pem client-key.pem

41. Authentication config • Config options… • ENABLE_SOAP_SSL is FALSE by default • <SUBSYS>_SOAP_SSL_PORT • Set this to a different port for each SUBSYS you want to talk to over ssl, the default is a random port • Example: SCHEDD_SOAP_SSL_PORT=1980 • SOAP_SSL_SERVER_KEYFILE is required and has no default • The file containing the server’s certificate AND private key, i.e. “keyfile” after cat server-cert.pem server-key.pem > keyfile

42. Authentication config • Config options continue… • SOAP_SSL_CA_FILE is required • The file containing public CA certificates used in signing client certificates, e.g. demoCA/cacert.pem • All options except SOAP_SSL_PORT have an optional SUBSYS_* version • For instance, turn on SSL for everyone except the Collector with • ENABLE_SOAP_SSL=TRUE • COLLECTOR_ENABLE_SOAP_SSL=FALSE

43. One last bit of config • The certificates we generated have a principal name, which is not standard across many authentication mechanisms • Condor maps authenticated names (here, principal names) to canonical names that are authentication method independent • This is done through mapfiles, given by SEC_CANONICAL_MAPFILE and SEC_USER_MAPFILE • Canonical map: • SSL .*emailAddress=(.*) \1 • “SSL” is the authentication method, “.*emailAddress….*” is a pattern to match against authenticated names, and “\1” is the canonical name, in this case the username on the email in the principal

44. HTTPS with Java • Setup keys… • keytool -import -keystore truststore -trustcacerts -file demoCA/cacert.pem • openssl pkcs12 -export -inkey client-key.pem -in client-cert.pem -out keystore • All the previous code stays the same, just set some properties • javax.net.ssl.trustStore, javax.net.ssl.keyStore, javax.net.ssl.keyStoreType, javax.net.ssl.keyStorePassword • Example: java -Djavax.net.ssl.trustStore=truststore -Djavax.net.ssl.keyStore=keystore -Djavax.net.ssl.keyStoreType=PKCS12 -Djavax.net.ssl.keyStorePassword=pass