Condor Project Computer Sciences Department University of Wisconsin-Madison Condor User Tutorial UK Condor Week NeSC 10 / 11 / 04

2 Morning Outline Background and principals User Tutorial: The Story of Frieda, the scientist Using Condor to manage jobs Using DAGMan to manage dependencies Condor-G Architecture and Mechanisms Globus Universe, Glide-In, etc.

3 The Condor Project (Established 85) Distributed High Throughput Computing research performed by a team of ~35 faculty, full time staff and students.

4 The Condor Project (Established 85) Distributed High Throughput Computing research performed by a team of ~35 faculty, full time staff and students who: face software engineering challenges in a distributed UNIX/Linux/NT environment are involved in national and international grid collaborations, actively interact with academic and commercial users, maintain and support large distributed production environments, and educate and train students. Funding – US Govt. (DoD, DoE, NASA, NSF, NIH), AT&T, IBM, INTEL, Microsoft, UW-Madison, …

5 A Multifaceted Project Harnessing the power of clusters - opportunistic and/or dedicated (Condor) Job management services for Grid applications (Condor-G, Stork) Fabric management services for Grid resources (Condor, GlideIns, NeST) Distributed I/O technology (Parrot, Kangaroo, NeST) Job-flow management (DAGMan, Condor, Hawk) Distributed monitoring and management (HawkEye) Technology for Distributed Systems (ClassAD, MW) Packaging and Integration (NMI, VDT)

6 Some software produced by the Condor Project Condor System ClassAd Library DAGMan Fault Tolerant Shell (FTSH) Hawkeye GCB MW NeST Stork Parrot Condor-G And others… all as open source

7 What is Condor? Condor converts collections of distributively owned workstations and dedicated clusters into a distributed high- throughput computing (HTC) facility. Condor manages both resources (machines) and resource requests (jobs) Condor has several unique mechanisms such as : ClassAd Matchmaking Process checkpoint/ restart / migration Remote System Calls Grid Awareness

8 Condor can manage a large number of jobs Managing a large number of jobs You specify the jobs in a file and submit them to Condor, which runs them all and keeps you notified on their progress Mechanisms to help you manage huge numbers of jobs (1000s), all the data, etc. Condor can handle inter-job dependencies (DAGMan) Condor users can set job priorities Condor administrators can set user priorities

9 Condor can manage Dedicated Resources… Dedicated Resources Compute Clusters Grid Resources Manage Node monitoring, scheduling Job launch, monitor & cleanup

10 …and Condor can manage non-dedicated resources Non-dedicated resources examples: Desktop workstations in offices Workstations in student labs Non-dedicated resources are often idle --- ~70% of the time! Condor can effectively harness the otherwise wasted compute cycles from non-dedicated resources

11 Meet Frieda. She is a scientist. But she has a big problem.

12 Friedas Application … Simulate the behavior of F(x,y,z) for 20 values of x, 10 values of y and 3 values of z (20*10*3 = 600 combinations) F takes on the average 3 hours to compute on a typical workstation ( total = 1800 hours ) F requires a moderate (128MB) amount of memory F performs moderate I/O - (x,y,z) is 5 MB and F(x,y,z) is 50 MB

13 I have 600 simulations to run. Where can I get help?

14 Install a Personal Condor!

15 Installing Condor Download Condor for your operating system Available as a free download from Stable –vs- Developer Releases Naming scheme similar to the Linux Kernel… Available for most Unix platforms and Windows NT

16 Or install from distributions Install from NMI: Condor-G only Install from VDT: Install from ROCKS: Condor can be installed on your own workstation, no root access required, no system administrator intervention needed

17 So Frieda Installs Personal Condor on her machine… What do we mean by a Personal Condor? Condor on your own workstation, no root access required, no system administrator intervention needed So after installation, Frieda submits her jobs to her Personal Condor…

18 your workstation personal Condor 600 Condor jobs

19 Personal Condor?! Whats the benefit of a Condor Pool with just one user and one machine?

20 Your Personal Condor will... … keep an eye on your jobs and will keep you posted on their progress … implement your policy on the execution order of the jobs … keep a log of your job activities … add fault tolerance to your jobs … implement your policy on when the jobs can run on your workstation

21 Getting Started: Submitting Jobs to Condor Choosing a Universe for your job Just use VANILLA for now Make your job batch-ready Creating a submit description file Run condor_submit on your submit description file

22 Making your job ready Must be able to run in the background: no interactive input, windows, GUI, etc. Can still use STDIN, STDOUT, and STDERR (the keyboard and the screen), but files are used for these instead of the actual devices Organize data files

23 Creating a Submit Description File A plain ASCII text file Tells Condor about your job: Which executable, universe, input, output and error files to use, command-line arguments, environment variables, any special requirements or preferences (more on this later) Can describe many jobs at once (a cluster) each with different input, arguments, output, etc.

24 Simple Submit Description File # Simple condor_submit input file # (Lines beginning with # are comments) # NOTE: the words on the left side are not # case sensitive, but filenames are! Universe = vanilla Executable = my_job Queue

25 Running condor_submit You give condor_submit the name of the submit file you have created condor_submit parses the file, checks for errors, and creates a ClassAd that describes your job(s) Sends your jobs ClassAd(s) and executable to the condor_schedd, which stores the job in its queue Atomic operation, two-phase commit View the queue with condor_q

26 Running condor_submit % condor_submit my_job.submit-file Submitting job(s). 1 job(s) submitted to cluster 1. % condor_q -- Submitter: perdita.cs.wisc.edu : : ID OWNER SUBMITTED RUN_TIME ST PRI SIZE CMD 1.0 frieda 6/16 06: :00:00 I my_job 1 jobs; 1 idle, 0 running, 0 held %

27 Another Submit Description File # Example condor_submit input file # (Lines beginning with # are comments) # NOTE: the words on the left side are not # case sensitive, but filenames are! Universe = vanilla Executable = /home/wright/condor/my_job.condor Input = my_job.stdin Output = my_job.stdout Error = my_job.stderr Arguments = -arg1 -arg2 InitialDir = /home/wright/condor/run_1 Queue

28 Clusters and Processes If your submit file describes multiple jobs, we call this a cluster Each job within a cluster is called a process or proc If you only specify one job, you still get a cluster, but it has only one process A Condor Job ID is the cluster number, a period, and the process number (23.5) Process numbers always start at 0

29 Example Submit Description File for a Cluster # Example condor_submit input file that defines # a cluster of two jobs with different iwd Universe = vanilla Executable = my_job Arguments = -arg1 -arg2 InitialDir = run_0 Queue Becomes job 2.0 InitialDir = run_1 Queue Becomes job 2.1

30 % condor_submit my_job.submit-file Submitting job(s). 2 job(s) submitted to cluster 2. % condor_q -- Submitter: perdita.cs.wisc.edu : : ID OWNER SUBMITTED RUN_TIME ST PRI SIZE CMD 1.0 frieda 6/16 06: :02:11 R my_job 2.0 frieda 6/16 06: :00:00 I my_job 2.1 frieda 6/16 06: :00:00 I my_job 3 jobs; 2 idle, 1 running, 0 held %

31 Submit Description File for a BIG Cluster of Jobs The initial directory for each job is specified with the $(Process) macro, and instead of submitting a single job, we use Queue 600 to submit 600 jobs at once $(Process) will be expanded to the process number for each job in the cluster (from 0 up to 599 in this case), so well have run_0, run_1, … run_599 directories All the input/output files will be in different directories!

32 Submit Description File for a BIG Cluster of Jobs # Example condor_submit input file that defines # a cluster of 600 jobs with different iwd Universe = vanilla Executable = my_job Arguments = -arg1 –arg2 InitialDir = run_$(Process) Queue 600

33 Using condor_rm If you want to remove a job from the Condor queue, you use condor_rm You can only remove jobs that you own (you cant run condor_rm on someone elses jobs unless you are root) You can give specific job IDs (cluster or cluster.proc), or you can remove all of your jobs with the -a option.

34 Temporarily halt a Job Use condor_hold to place a job on hold Kills job if currently running Will not attempt to restart job until released Use condor_release to remove a hold and permit job to be scheduled again

35 Using condor_history Once your job completes, it will no longer show up in condor_q You can use condor_history to view information about a completed job The status field (ST) will have either a C for completed, or an X if the job was removed with condor_rm

36 Getting from Condor By default, Condor will send you when your jobs completes With lots of information about the run If you dont want this , put this in your submit file: notification = never If you want every time something happens to your job (preempt, exit, etc), use this: notification = always

37 Getting from Condor (contd) If you only want in case of errors, use this: notification = error By default, the is sent to your account on the host you submitted from. If you want the to go to a different address, use this: notify_user =

38 A Jobs life story: The User Log file A UserLog must be specified in your submit file: Log = filename You get a log entry for everything that happens to your job: When it was submitted, when it starts executing, preempted, restarted, completes, if there are any problems, etc. Very useful! Highly recommended!

39 Sample Condor User Log 000 ( ) 05/25 19:10:03 Job submitted from host: ( ) 05/25 19:12:17 Job executing on host: ( ) 05/25 19:13:06 Job terminated. (1) Normal termination (return value 0) Usr 0 00:00:37, Sys 0 00:00:00 - Run Remote Usage Usr 0 00:00:00, Sys 0 00:00:05 - Run Local Usage Usr 0 00:00:37, Sys 0 00:00:00 - Total Remote Usage Usr 0 00:00:00, Sys 0 00:00:05 - Total Local Usage Run Bytes Sent By Job Run Bytes Received By Job Total Bytes Sent By Job Total Bytes Received By Job...

40 Uses for the User Log Easily read by human or machine C++ library and Perl Module for parsing UserLogs is available log_xml=True – XML formatted Event triggers for meta-schedulers Like DagMan… Visualizations of job progress Condor JobMonitor Viewer

Condor JobMonitor Screenshot

42 Job Priorities w/ condor_prio condor_prio allows you to specify the order in which your jobs are started Higher the prio #, the earlier the job will start % condor_q -- Submitter: perdita.cs.wisc.edu : : ID OWNER SUBMITTED RUN_TIME ST PRI SIZE CMD 1.0 frieda 6/16 06: :02:11 R my_job % condor_prio % condor_q -- Submitter: perdita.cs.wisc.edu : : ID OWNER SUBMITTED RUN_TIME ST PRI SIZE CMD 1.0 frieda 6/16 06: :02:13 R my_job

43 Want other Scheduling possibilities? Use the Scheduler Universe In addition to VANILLA, another job universe is the Scheduler Universe. Scheduler Universe jobs run on the submitting machine and serve as a meta-scheduler. DAGMan meta-scheduler included

44 DAGMan Directed Acyclic Graph Manager DAGMan allows you to specify the dependencies between your Condor jobs, so it can manage them automatically for you. (e.g., Dont run job B until job A has completed successfully.)

45 What is a DAG? A DAG is the data structure used by DAGMan to represent these dependencies. Each job is a node in the DAG. Each node can have any number of parent or children nodes – as long as there are no loops! Job A Job BJob C Job D

46 A DAG is defined by a.dag file, listing each of its nodes and their dependencies: # diamond.dag Job A a.sub Job B b.sub Job C c.sub Job D d.sub Parent A Child B C Parent B C Child D each node will run the Condor job specified by its accompanying Condor submit file Defining a DAG Job A Job BJob C Job D

47 Submitting a DAG To start your DAG, just run condor_submit_dag with your.dag file, and Condor will start a personal DAGMan daemon which to begin running your jobs: % condor_submit_dag diamond.dag condor_submit_dag submits a Scheduler Universe Job with DAGMan as the executable. Thus the DAGMan daemon itself runs as a Condor job, so you dont have to baby-sit it.

48 DAGMan Running a DAG DAGMan acts as a meta-scheduler, managing the submission of your jobs to Condor based on the DAG dependencies. Condor Job Queue C D A A B.dag File

49 DAGMan Running a DAG (contd) DAGMan holds & submits jobs to the Condor queue at the appropriate times. Condor Job Queue C D B C B A

50 DAGMan Running a DAG (contd) In case of a job failure, DAGMan continues until it can no longer make progress, and then creates a rescue file with the current state of the DAG. Condor Job Queue X D A B Rescue File

51 DAGMan Recovering a DAG Once the failed job is ready to be re-run, the rescue file can be used to restore the prior state of the DAG. Condor Job Queue C D A B Rescue File C

52 DAGMan Recovering a DAG (contd) Once that job completes, DAGMan will continue the DAG as if the failure never happened. Condor Job Queue C D A B D

53 DAGMan Finishing a DAG Once the DAG is complete, the DAGMan job itself is finished, and exits. Condor Job Queue C D A B

54 Additional DAGMan Features Provides other handy features for job management… nodes can have PRE & POST scripts failed nodes can be automatically re- tried a configurable number of times job submission can be throttled

55 Another sample DAGMan submit file # Filename: diamond.dag Job A A.condor Job B B.condor Job C C.condor Job D D.condor Script PRE A top_pre.csh Script PRE B mid_pre.perl $JOB Script POST B mid_post.perl $JOB $RETURN Script PRE C mid_pre.perl $JOB Script POST C mid_post.perl $JOB $RETURN Script PRE D bot_pre.csh PARENT A CHILD B C PARENT B C CHILD D Retry C 3 Job A Job BJob C Job D

56 DAGMan, cont. DAGMan can help w/ visualization of the DAG Can create input files for AT&Ts graphviz package (dot input). Why not just use make? In the works: dynamic DAGs.

57 And Even Bigger: 744 Files, 387 Nodes Argonne National Laboratory

58 Weve seen how Condor will … keep an eye on your jobs and will keep you posted on their progress … implement your policy on the execution order of the jobs … keep a log of your job activities … add fault tolerance to your jobs ?

59 What if each job needed to run for 20 days? What if I wanted to interrupt a job with a higher priority job?

60 Condors Standard Universe to the rescue! Condor can support various combinations of features/environments in different Universes Different Universes provide different functionality for your job: Vanilla – Run any Serial Job Scheduler – Plug in a meta-scheduler Standard – Support for transparent process checkpoint and restart

61 Process Checkpointing Condors Process Checkpointing mechanism saves all the state of a process into a checkpoint file Memory, CPU, I/O, etc. The process can then be restarted from right where it left off Typically no changes to your jobs source code needed – however, your job must be relinked with Condors Standard Universe support library

62 Relinking Your Job for submission to the Standard Universe To do this, just place condor_compile in front of the command you normally use to link your job: condor_compile gcc -o myjob myjob.c OR condor_compile f77 -o myjob filea.f fileb.f OR condor_compile make –f MyMakefile

63 Limitations in the Standard Universe Condors checkpointing is not at the kernel level. Thus in the Standard Universe the job may not Fork() Use kernel threads Use some forms of IPC, such as pipes and shared memory Many typical scientific jobs are OK

64 When will Condor checkpoint your job? Periodically, if desired For fault tolerance To free the machine to do a higher priority task (higher priority job, or a job from a user with higher priority) Preemptive-resume scheduling When you explicitly run condor_checkpoint, condor_vacate, condor_off or condor_restart command

65 Standalone Checkpointing Can use Condor Projects checkpoint technology outside of Condor… SIGTSTP = checkpoint and exit SIGUSR2 = periodic checkpoint condor_compile cc myapp.c –o myapp myapp -_condor_ckpt foo-image.ckpt … myapp -_condor_restart foo-image.ckpt

66 Checkpoint Library Interface void init image with file name( char *ckpt file name ) void init image with file descriptor( int fd ) void ckpt() void ckpt and exit() void restart() void condor ckpt disable() void condor ckpt enable() int condor warning config( const char *kind,const char *mode) extern int condor compress ckpt

67 What Condor Daemons are running on my machine, and what do they do?

68 Condor Daemon Layout Personal Condor / Central Manager master collector negotiator scheddstartd = Process Spawned

69 condor_master Starts up all other Condor daemons If there are any problems and a daemon exits, it restarts the daemon and sends to the administrator Checks the time stamps on the binaries of the other Condor daemons, and if new binaries appear, the master will gracefully shutdown the currently running version and start the new version master

70 condor_master (contd) Acts as the server for many Condor remote administration commands: condor_reconfig, condor_restart, condor_off, condor_on, condor_config_val, etc.

71 condor_startd Represents a machine to the Condor system Responsible for starting, suspending, and stopping jobs Enforces the wishes of the machine owner (the owners policy… more on this soon) master startd

72 condor_schedd Represents users to the Condor system Maintains the persistent queue of jobs Responsible for contacting available machines and sending them jobs Services user commands which manipulate the job queue: condor_submit,condor_rm, condor_q, condor_hold, condor_release, condor_prio, … master scheddstartd

73 condor_collector Collects information from all other Condor daemons in the pool Directory Service / Database for a Condor pool Each daemon sends a periodic update called a ClassAd to the collector Services queries for information: Queries from other Condor daemons Queries from users (condor_status) schedd collector master startd

74 condor_negotiator Performs matchmaking in Condor Gets information from the collector about all available machines and all idle jobs Tries to match jobs with machines that will serve them Both the job and the machine must satisfy each others requirements master collector negotiator scheddstartd

75 Happy Day! Friedas organization purchased a Beowulf Cluster! Frieda Installs Condor on all the dedicated Cluster nodes, and configures them with her machine as the central manager… Now her Condor Pool can run multiple jobs at once

76 your workstation personal Condor 600 Condor jobs Condor Pool

77 Layout of the Condor Pool Central Manager (Friedas) master collector negotiator schedd startd = ClassAd Communication Pathway = Process Spawned Cluster Node master startd Cluster Node master startd

78 condor_status % condor_status Name OpSys Arch State Activity LoadAv Mem ActvtyTime haha.cs.wisc. IRIX65 SGI Unclaimed Idle :00:04 antipholus.cs LINUX INTEL Unclaimed Idle :28:42 coral.cs.wisc LINUX INTEL Claimed Busy :27:21 doc.cs.wisc.e LINUX INTEL Unclaimed Idle :20:04 dsonokwa.cs.w LINUX INTEL Claimed Busy :01:45 ferdinand.cs. LINUX INTEL Claimed Suspended :00:55 LINUX INTEL Unclaimed Idle :03:28 LINUX INTEL Unclaimed Idle :03:29

79 Frieda tries out static parallel jobs: MPI Universe Schedule and start an MPICH job on dedicated resources ## MPI example submit description file universe = MPI executable = simplempi log = logfile input = infile.$(NODE) output = outfile.$(NODE) error = errfile.$(NODE) machine_count = 4 queue

80 The Boss says Frieda can add her co-workers desktop machines into her Condor pool as well… but only if they can also submit jobs. (Boss Fat Cat)

81 Layout of the Condor Pool Central Manager (Friedas) master collector negotiator schedd startd = ClassAd Communication Pathway = Process Spawned Desktop schedd startd master Desktop schedd startd master Cluster Node master startd Cluster Node master startd

82 Some of the machines in the Pool do not have enough memory or scratch disk space to run my job!

83 Specify Requirements! An expression (syntax similar to C or Java) Must evaluate to True for a match to be made Universe = vanilla Executable = my_job InitialDir = run_$(Process) Requirements = Memory >= 256 && Disk > Queue 600

84 Specify Rank! All matches which meet the requirements can be sorted by preference with a Rank expression. Higher the Rank, the better the match Universe = vanilla Executable = my_job Arguments = -arg1 –arg2 InitialDir = run_$(Process) Requirements = Memory >= 256 && Disk > Rank = (KFLOPS*10000) + Memory Queue 600

85 What attributes can I reference in Requirements/Rank ? Answer: Any attributes that appear in the machine or job classad Out of the box, Condor has ~70 attributes per machine classad and ~70 attributes per job classad Sites can add their own custom attributes to machine or job classads To see all ad attributes: condor_status –long (for machine classads) condor_q –long (for job classads)

86 Condor ClassAds ClassAds are at the heart of Condor ClassAds are a set of uniquely named expressions; each expression is called an attribute combine query and data semi-structured : no fixed schema extensible

87 Sample ClassAd MyType = "Machine" TargetType = "Job" Machine = "froth.cs.wisc.edu" Arch = "INTEL" OpSys = "SOLARIS251" Disk = Memory = 128 KeyboardIdle = 173 LoadAvg = Requirements = TARGET.Owner=="smith" || LoadAvg 15*60

88 ClassAds, cont. Attributes consist of An attribute name (case-insensitive!) An attribute value, composed of literals and/or attribute references connected by operators. Requirements = KeyboardIdle > 300

89 ClassAds, cont. Literals Integers, Reals Booleans TRUE (=1) and FALSE (=0) Strings Enclosed in double quotations Use backslash (\) to escape Lastname = \Smith\ UNDEFINED (three-valued logic) Example: Beefymachine is UNDEFINED if Memory attribute does not exist: BeefyMachine = Memory > 1024 ERROR Functions Can be supplied via a shared library

90 ClassAds, cont Operators - (unary negation) (high precedence) * / + - (addition, subtraction) = > == != =?= =!= && || (low precedence)

91 ClassAds, cont. Meta-operators =?= and =!= == and != can return True, False, Undefined, or Error =?= and =!= can return True or False; think of them like is identical and is not identical Examples: 10 == UNDEFINED is UNDEFINED UNDEFINED == UNDEFINED is UNDEFINED 10 =?= UNDEFINED is FALSE UNDEFINED =?= UNDEFINED is TRUE

92 ClassAds, cont. Attribute References Scope Prefix? If the prefix is MY., the attribute is looked up in ClassAd A. If the named attribute does not exist in A, the value of the reference is UNDEFINED. If the prefix is TARGET., the attribute is looked up in ClassAd B. If the named attribute does not exist in B, the value of the reference is UNDEFINED. No scope prefix? First try ad A, then B. If it is not found in either, then UNDEFINED. Special attribute: CurrentTime, which evaluates to the integer Unix epoch time (number of seconds since Jan 1 st, 1970). If the reference refers to an expression that is itself in the process of being evaluated, there is a circular dependency in the evaluation. The value of the reference is ERROR.

93 ClassAd Matching Two ClassAds are said to match if the Requirements expression from both ads evaluates to True when evaluated within the context of each other. The Rank expression is the goodness of the match (higher is better).

94 How can my jobs access their data files?

95 Access to Data in Condor Use Shared Filesystem if available No shared filesystem? Remote System Calls (in the Standard Universe) Condor File Transfer Service Can automatically send back changed files Atomic transfer of multiple files Remote I/O Proxy Socket

96 Standard Universe Remote System Calls I/O System calls trapped and sent back to submit machine Allows Transparent Migration Across Administrative Domains Checkpoint on machine A, restart on B No Source Code changes required Language Independent Opportunities For Application Steering Example: Condor tells customer process how to open files For compression on the fly More…

97 Customer Job Job Startup Submit Schedd Shadow Startd Starter Condor Syscall Lib

98 condor_q -io c01(69)% condor_q -io -- Submitter: c01.cs.wisc.edu : : c01.cs.wisc.edu ID OWNER READ WRITE SEEK XPUT BUFSIZE BLKSIZE 72.3 edayton [ no i/o data collected yet ] 72.5 edayton 6.8 MB 0.0 B KB/s KB 32.0 KB 73.0 edayton 6.4 MB 0.0 B KB/s KB 32.0 KB 73.2 edayton 6.8 MB 0.0 B KB/s KB 32.0 KB 73.4 edayton 6.8 MB 0.0 B KB/s KB 32.0 KB 73.5 edayton 6.8 MB 0.0 B KB/s KB 32.0 KB 73.7 edayton [ no i/o data collected yet ] 0 jobs; 0 idle, 0 running, 0 held

99 Condor File Transfer Set Should_Transfer_Files YES : Always transfer files to execution site NO : Rely on a shared filesystem IF_NEEDED : will automatically transfer the files if the submit and execute machine are not in the same FileSystemDomain Set When_To_Transfer_Output ON_EXIT or ON_EXIT_OR_VACATE Universe = vanilla Executable = my_job Requirements = Memory >= 256 && Disk > Should_Transfer_Files = IF_NEEDED When_To_Transfer_Output = IF_NEEDED Transfer_input_files = dataset$(Process), common.data Transfer_output_files = TheAnswer.dat Queue 600

100 Remote I/O Socket Job can request that the condor_starter process on the execute machine create a Remote I/O Proxy Socket Used for online access of file on submit machine – without Standard Universe. Use in Vanilla, Java, … Libraries provided for Java and for C, e.g. : Java: FileInputStream -> ChirpInputStream C : open() -> chirp_open() Or use Parrot!

101 Job Fork startershadow Home File System I/O Library I/O ServerI/O Proxy Secure Remote I/O Local System Calls Local I/O (Chirp) Execution Site Submission Site

102 I am adding nodes to the Cluster… but the Engineering Department has priority on these nodes. (Boss Fat Cat) Policy Configuration

103 Machine Policy coming tomorrow… Ooohhhh… the suspense!

104 The Cluster is fine. But not the desktop machines. Condor can only use the desktops when they would otherwise be idle. (Boss Fat Cat) Policy Configuration, cont

105 Machine Policy coming tomorrow… Ooohhhh… the suspense!

106 I want to use Java. Is there any easy way to run Java programs via Condor?

107 Java Universe Job universe = java executable = Main.class jar_files = MyLibrary.jar input = infile output = outfile arguments = Main queue condor_submit

108 Why not use Vanilla Universe for Java jobs? Java Universe provides more than just inserting java at the start of the execute line Knows which machines have a JVM installed Knows the location, version, and performance of JVM on each machine Provides more information about Java job completion than just JVM exit code Program runs in a Java wrapper, allowing Condor to report Java exceptions, etc.

109 Java support, cont. condor_status -java Name JavaVendor Ver State Activity LoadAv Mem aish.cs.wisc. Sun Microsy Owner Idle anfrom.cs.wis Sun Microsy Owner Idle babe.cs.wisc. Sun Microsy Claimed Busy

110 My MPI programs are running on the dedicated nodes. Can I run parallel jobs on the non-dedicated nodes?

111 PVM Universe Allows dynamic, opportunistic PVM Number of nodes can change dynamically Specify a minimum and maximum number of nodes Works well for Master/Worker paradigm Differences from regular PVM pvm_addhost() is non-blocking pvm_notify enhanced w/ suspend state PVM arch string enhanced Can also use MW … does all the work for you.

112 Non-dedicated Parallel Job: PVM Universe, Cont. # The job is a PVM universe job. universe = PVM # The executable of the master PVM program is ``master.exe''. executable = master.exe input = "in.dat" output = "out.dat" error = "err.dat" ################### Machine class 0 ################## Requirements = (Arch == "INTEL") && (OpSys == "LINUX") # We want at least 2 machines in class 0 before starting the # program. We can use up to 4 machines. machine_count = 2..4 queue ################### Machine class 1 ################## Requirements = (Arch == "SUN4x") && (OpSys == "SOLARIS26") # We can use up to 50 more…. machine_count = queue

113 General User Commands condor_status View Pool Status condor_qView Job Queue condor_submitSubmit new Jobs condor_rmRemove Jobs condor_prioIntra-User Prios condor_historyCompleted Job Info condor_submit_dagSpecify Dependencies condor_checkpointForce a checkpoint condor_compileLink Condor library

114 Administrator Commands condor_vacateLeave a machine now condor_onStart Condor condor_offStop Condor condor_reconfigReconfig on-the-fly condor_config_valView/set config condor_userprioUser Priorities condor_statsView detailed usage accounting stats

115 CondorView Usage Graph

116 Some of the command-line tools more in depth: condor_submit condor_submit [options] submit-file Some useful options -d Disable file permission checks -n Submit to a specific schedd -v Verbose: display Job Ads submitted Can read from stdin; example: cat myjob.sub | condor_submit –d is the same as condor_submit –d myjob.sub

117 Job Submit files: Built-in and Defined Macros Macros are resolved by condor_submit before creating the Job ClassAd. Weve seen the $(Process) built-in macro. There are others: $(Cluster) $ENV(foo) $RANDOM_CHOICE(x,y,z,…) $(Dollar) User Defined macros can be defined anytime in the submit file with the syntax = and then used with the form $(macro_name).

118 Job Submit File Example # Run foo –mem 512 –seed [0|1|2] # Universe = vanilla Executable = foo Memory = 512 +MyHomeDir = $ENV(HOME) Requirements = Memory > $(Memory) Arguments = -mem $(Memory) \ -seed $RANDOM_CHOICE(0,1,2) output = log.$(cluster).$(process) Queue 100

119 Sad fact: Macros improve your spelling. Consider this submit file: Universe = vanilla Executable = foo Requirments = Memory > 512 Out = foo.out Err = foo.err Queue Notice any problems? Hint: stdout is still remapped to /dev/null stderr is still remapped to /dev/null the job may run on a 128meg machine And because of Macros, condor_submit will not report any errors…

120 Job submit files: Match Ad Substitution macros A substitution macro takes the value of the expression from the resource (machine ClassAd) after a match has been made. These macros look like: $$(attribute) An alternate form looks like: $$(attribute:string_if_attribute_undefined)

121 Example Submit File # Run on Solaris or Linux Universe = vanilla Requirements = Opsys==Linux || Opsys == Solaris Executable = foo.$$(opsys) Arguments = -textures $$(texturedir:/usr/local/alias/textures) queue

122 Submit file general entries Universe – Runtime environment (vanilla, standard, scheduler, pvm, mpi, globus, … ) Executable – Name of binary to run Input – file to redirect as stdin, or the keyboard (defaults to /dev/null) Output – file to redirect stdout (defaults to /dev/null) Error – file to redirect stderr (defaults to /dev/null) Note: do not use the same filename for output & error.

123 Submit file: File Transfer Mechanism options Should_Transfer_Files When_To_Transfer_Output Transfer_input_files Transfer_output_files

124 Submit File: Job Failure Policy Expressions You can supply job failure policy expressions in the submit file. Can be used to describe a successful run, or what to do in the face of failure. on_exit_remove = on_exit_hold = periodic_remove = periodic_hold = periodic_release =

125 Job Failure Policy Examples Do not remove from queue (i.e. reschedule) if exits with a signal: on_exit_remove = ExitBySignal == False Place on hold if exits with nonzero status or ran for less than an hour: on_exit_hold = ((ExitBySignal==False) && (ExitSignal != 0)) || ((CurrentTime – JobStartDate) < 3600) Place on hold if job has spent more than 50% of its time suspended: periodic_hold = CumulativeSuspensionTime > (RemoteWallClockTime / 2.0)

126 Submit file: Options to move the executable Copy_to_spool = [True | False] Defaults to be True; often not needed, and often slows down submit considerably. Transfer_executable = [True | False] Defaults to be True; could be wasteful if executable is pre-staged on execute machine.

127 Submit file: Job Environment Environment = var=val; var1=val1; … Getenv = [True | False] Defaults to be false. Often GetEnv=TRUE fixes problems due to an empty environment, BUT Be wary – the submit machines environment may not make sense on the execute machine! Note: job will always be started with a CONDOR_SCRATCH_DIR environment variable to a subdir that is removed when the job leaves.

128 Submit file: priority settings Nice_user = [true | false] - use a priority factor of 1,000,000, so everyone can run ahead of this job Priority = - specify job prio ala condor_prio +AccountingGroup = foo - use a specified accounting principle, instead of the user.

129 How are user priorities handled in Condor?

130 User Priorities A users effective priority determines their usage Like golf : lower number is better Machines are allocated as an inverse ratio of priority Effective Priority = Real Priority * Priority Factor Real Priority = Set by Condor Priority Factor = Set by Administrator

131 User Priorities, cont. To view user priority information, use condor_userprio –all This will show info for all current users of the system. To see the entire accounting database, do condor_userprio –all –allusers (see output)

132 What is a negotiation cycle ?

133 What happens if the workstation running the Central Manager crashes?

134 What happens if the workstation running my job (execute machine) crashes?

135 What happens if the workstation running my schedd (submit machine) crashes?

136 Disconnected Shadow/Starter Once upon a time, only one answer: job restarts. Now for Vanilla and Java universe jobs, Condor now supports reestablishing the connection between the submitting and executing machines. To take advantage of this feature, the user must put the following line into their jobs submit description file: +JobLeaseDuration = For example: +JobLeaseDuration = 1200

137 Why is my job not running?

138 Troubleshooting stuck jobs Try condor_q –analyze Check ClassAd requirements Maybe user priority? Check job log or ShadowLog – maybe job is starting and failing right away.

139 Back to the Story… Frieda Needs Remote Resources…

140 Frieda Builds a Grid! First Frieda takes advantage of her Condor friends! She knows people with their own Condor pools, and gets permission to access their resources flock She then configures her Condor pool to flock to these pools

141 your workstation Friendly Condor Pool personal Condor 600 Condor jobs Condor Pool

142 How Flocking Works Add a line to your condor_config : FLOCK_HOSTS = Pool-Foo, Pool-Bar Schedd Collector Negotiator Central Manager (CONDOR_HOST ) Collector Negotiator Pool-Foo Central Manager Collector Negotiator Pool-Bar Central Manager Submit Machine

143 Condor Flocking Remote pools are contacted in the order specified until jobs are satisfied The list of remote pools is a property of the Schedd, not the Central Manager So different users can Flock to different pools And remote pools can allow specific users User-priority system is flocking-aware A pools local users can have priority over remote users flocking in.

144 Condor Flocking, cont. Flocking is Condor specific technology… Frieda also has access to Globus resources she wants to use She has certificates and access to Globus gatekeepers at remote institutions But Frieda wants Condors queue management features for her Globus jobs! She installs Condor-G so she can submitGlobus Universe jobs to Condor

145 Condor-G: Access non-Condor Grid resources Globus middleware deployed across entire Grid remote access to computational resources dependable, robust data transfer Condor job scheduling across multiple resources strong fault tolerance with checkpointing and migration layered over Globus as personal batch system for the Grid

146 Frieda Submits a Globus Universe Job In her submit description file, she specifies: Universe = Globus Which Globus Gatekeeper to use Optional: Location of file containing your Globus certificate universe = globus globusscheduler = beak.cs.wisc.edu/jobmanager executable = progname queue

147 How It Works Schedd LSF Personal CondorGlobus Resource

148 How It Works Schedd LSF Personal CondorGlobus Resource 600 Globus jobs

149 How It Works Schedd LSF Personal CondorGlobus Resource GridManager 600 Globus jobs

150 How It Works Schedd JobManager LSF Personal CondorGlobus Resource GridManager 600 Globus jobs

151 How It Works Schedd JobManager LSF User Job Personal CondorGlobus Resource GridManager 600 Globus jobs

152 Condor Globus Universe

153 Globus Universe Concerns What about Fault Tolerance? Local Crashes What if the submit machine goes down? Network Outages What if the connection to the remote Globus jobmanager is lost? Remote Crashes What if the remote Globus jobmanager crashes? What if the remote machine goes down?

154 Changes to the Globus JobManagerfor Fault Tolerance Ability to restart a JobManager Enhanced two-phase commit submit protocol

155 Globus Universe Fault-Tolerance: Submit-side Failures All relevant state for each submitted job is stored persistently in the Condor job queue. This persistent information allows the Condor GridManager upon restart to read the state information and reconnect to JobManagers that were running at the time of the crash. If a JobManager fails to respond…

156 Globus Universe Fault-Tolerance: Lost Contact with Remote Jobmanager Can we contact gatekeeper? Yes – network was down No – machine crashed or job completed Yes - jobmanager crashedNo – retry until we can talk to gatekeeper again… Can we reconnect to jobmanager? Has job completed? No – is job still running? Yes – update queue Restart jobmanager

157 Globus Universe Fault-Tolerance: Credential Management Authentication in Globus is done with limited-lifetime X509 proxies Proxy may expire before jobs finish executing Condor can put jobs on hold and user to refresh proxy Todo: Interface with MyProxy…

158 But Frieda Wants More… She wants to run standard universe jobs on Globus-managed resources For matchmaking and dynamic scheduling of jobs For job checkpointing and migration For remote system calls

159 One Solution: Condor-G GlideIn Frieda can use the Globus Universe to run Condor daemons on Globus resources When the resources run these GlideIn jobs, they will temporarily join her Condor Pool She can then submit Standard, Vanilla, PVM, or MPI Universe jobs and they will be matched and run on the Globus resources

160 your workstation Friendly Condor Pool personal Condor 600 Condor jobs Globus Grid PBS LSF Condor Condor Pool glide-in jobs

161 your workstation Remote Condor Pool personal Condor 600 Condor jobs Globus Grid PBS LSF Condor Local Condor Pool glide-in jobs

162 Gate Keeper Local Job Scheduler Job Manager Grid Man Customer AG Condor-G CondorSubmit X 2 Globus Resource App AG Glide in Application Match Maker

163

164 GlideIn Concerns What if a Globus resource kills my GlideIn job? That resource will disappear from your pool and your jobs will be rescheduled on other machines Standard universe jobs will resume from their last checkpoint like usual What if all my jobs are completed before a GlideIn job runs? If a GlideIn Condor daemon is not matched with a job in 10 minutes, it terminates, freeing the resource

165 In Review With Condor-G Frieda can… … manage her compute job workload … access remote compute resources on the Grid via Globus Universe jobs … carve out her own personal Condor Pool from the Grid with GlideIn technology

166 Condor-G Matchmaking Alternative to Glidein: Use Condor-G matchmaking with globus universe jobs Allows Condor-G to dynamically assign computing jobs to grid sites An example of lazy planning

167 Condor-G Matchmaking, cont. Normally a globus universe job must specify the site in the submit description file via the globusscheduler attribute like so: Executable = foo Universe = globus Globusscheduler = beak.cs.wisc.edu/jobmanager-pbs queue

168 Condor-G Matchmaking, cont. With matchmaking, globus universe jobs can use requirements and rank: Executable = foo Universe = globus Globusscheduler = $$(GatekeeperUrl) Requirements = arch == LINUX Rank = NumberOfNodes Queue The $$(x) syntax inserts information from the target ClassAd when a match is made.

169 Condor-G Matchmaking, cont. Where do these target ClassAds representing Globus gatekeepers come from? Several options: Simple script on gatekeeper publishes an ad via condor_advertise command-line utility (method used by D0 JIM, USCMS) Program to query Globus MDS and convert information into ClassAd (method used by EDG) Run HawkEye with appropriate plugins on the gatekeeper An explanation of Condor-G matchmaking setup see

170 Some Recent Condor-G Features Condor-G can submit and manage jobs not only in Condor and Globus managed grids, but also to Nordugrid ( Oracle Database (using Oracle Call Interface [OCI] API) UNICORE PBS LSF

171 Some recent or soon to arrive Condor-G / DAGMan features, cont. Multi-Tier job submission Allows jobs to be submitted from a machine which need not be always connected to the network (e.g. a laptop) condor_submit sends job Classad and job sandbox to a remote condor_schedd condor_fetch_sandbox used to retrieve output from remote condor_schedd when job completes SOAP interface Job submission to additional remote systems Full support for matchmaking

172 I want to create a portal to Condor. Is there a developer API to Condor?

173 Developer API Do not underestimate the flexibility of the command line tools! Other possibilities Condor Perl Module DRMAA Condor GAHP Condor SOAP (Web Service) Interface ClassAd Library (C++ and Java)

174 Thank you!