| ARCSUB(1) | NorduGrid Users Manual | ARCSUB(1) |
arcsub - ARC Submission
The arcsub command is used for submitting jobs to Grid enabled computing resources.
arcsub [options] [filename ...]
arcsub is the key command when submitting jobs to Grid enabled computing resources with the ARC client. As default arcsub is able to submit jobs to A-REX, CREAM and EMI ES enabled computing elements (CEs), and as always for successful submission you need to be authenticated at the targeted computing services. Since arcsub is build on a modular library, modules can be installed which enables submission to other targets, e.g. the classic ARC CE Grid-Manager.
Job submission can be accomplished by specifying a job description file to submit as an argument. arcsub will then by default perform resource discovery on the Grid and then the discovered resources will be matched to the job description and ranked according to the chosen broker (--broker option). If no Grid environment has been configured, please contact your system administrator, or setup one yourself in the client configuration file (see files section). Another option is to explicitly specify a registry service (or multiple) to arcsub using the --index option, which accepts an URL, alias or group. Alternatively a specific CE (or multiple) can be targeted by using the --cluster option. If such a scenario is the most common, it is worthwhile to specify those CEs in the client configuration as default services, which makes it superfluous to specify them as argument. In the same manner aliases and groups, defined in the configuration file, can be utilized, and can be used as argument to the --cluster or --index options. In all of the above scenarios arcsub obtains resource information from the services which is then used for matchmaking against the job description, however that step can be avoided by specifying the --direct option, in which case the job description is submitted directly to first specified endpoint.
The format of a classic GRIDFTP-based cluster URLs:
[ldap://]<hostname>[:2135/nordugrid-cluster-name=<hostname>,Mds-Vo-name=local,o=grid]
Only the hostname part has to be specified, the rest of the URL is
automatically generated.
The format of an A-REX URL is:
[https://]<hostname>[:<port>][/<path>]
Here the port is 443 by default, but the path cannot be guessed, so if it is
not specified, then the service is assumed to live on the root path.
Job descriptions can also be specified using the --jobdescrfile option which expect the file name of the description as argument, or the --jobdescrstring option which expect as argument the job description as a string, and both options can be specified multiple times and one does not exclude the other. The default supported job description languages are xRSL and EMIES ADL.
If the job description is successfully submitted a job-ID is returned and printed. This job-ID uniquely identifies the job while it is being executed. On the other hand it is also possible that no CEs matches the constraints defined in the description in which case no submission will be done. Upon successful submission, the job-ID along with more technical job information is stored in the job-list file (described below). The stored information enables the job management commands of the ARC client to manage jobs easily, and thus the job-ID need not to be saved manually. By default the job-list file is stored in the .arc directory in the home directory of the user, however another location can be specified using the --joblist option taking the location of this file as argument. If the --joblist option was used during submission, it should also be specified in the consecutive commands when managing the job. If a Computing Element has multiple job submission interfaces (e.g. gridftp, EMI-ES, BES), then the brokering algorithm will choose one of them. With the --submissioninterface option the requested interface can be specified, and in that case only those Computing Elements will be considered which has that specific interface, and only that interface will be used to submit the jobs.
As mentioned above registry or index services can be specified with the --index option. Specifying one or multiple index servers instructs the arcsub command to query the servers for registered CEs, the returned CEs will then be matched against the job description and those matching will be ranked by the chosen broker (see below) and submission will be tried in order until successful or reaching the end. From the returned list of CEs it might happen that a troublesome or undesirable CE is selected for submission, in that case it possible to reject that cluster using the --rejectdiscovery option and providing the URL (or just the hostname) of the CE, which will disregard that CE as a target for submission.
When multiple CEs are targeted for submission, the resource broker will be used to filter out CEs which do not match the job description requirements and then rank the remaining CEs. The broker used by default will rank the CEs randomly, however a different broker can be chosen by using the --broker option, which takes the name of the broker as argument. The broker type can also be specified in client.conf. The brokers available can be seen using arcsub -P. By default the following brokers are available:
Before submission, arcsub performs an intelligent modification of the job description (adding or modifying attributes, even converting the description language to fit the needs of the CE) ensuring that it is valid. The modified job description can be printed by specifying the --dumpdescription option. The format, i.e. job description language, of the printed job description cannot be specified, and will be that which will be sent to and accepted by the chosen target. Further information from arcsub can be obtained by increasing the verbosity, which is done with the --debug option where the default verbosity level is WARNING. Setting the level to DEBUG will show all messages, while setting it to FATAL will only show fatal log messages.
To validate your job description without actually submitting a job, use the --dryrun option: it will capture possible syntax or other errors, but will instruct the site not to submit the job for execution. Only the grid-manager (ARC0) and A-REX (ARC1) CEs support this feature.
Submission of a job description file "helloworld.adl" to
the Grid
arcsub helloworld.adl
A information index server (registry) can also be queried for CEs
to submit to:
arcsub -g registry.example.com helloworld.adl
Submission of a job description file "helloworld.adl" to
ce.example.com:
arcsub -c ce.example.com helloworld.adl
Direct submission to a CE is done as:
arcsub --direct -c cd.example.com helloworld.adl
The job description can also be specified directly on the command
line as shown in the example, using the XRSL job description language:
arcsub -c example.com/arex -e \
´&(executable="/bin/echo")(arguments="Hello
World!")´
When submitting against CEs retrieved from information index
servers it might be useful to do resource brokering:
arcsub -g registry.example.com -b FastestQueue helloworld.adl
If the job has a large input data set, it can be useful to send it
to a CE where those files are already cached. The ACIX broker can be used
for this:
arcsub -g registry.example.com -b
PythonBroker:ACIXBroker.ACIXBroker:https://cacheindex.ndgf.org:6443/data/index
helloworld.adl
Disregarding a specific CE for submission submitting against an
information index server:
arcsub -g registry.example.com -R badcomputingelement.com/arex
helloworld.adl
Dumping the job description is done as follows:
arcsub -c example.com/arex -x helloworld.adl
APACHE LICENSE Version 2.0
ARC software is developed by the NorduGrid Collaboration (http://www.nordugrid.org), please consult the AUTHORS file distributed with ARC. Please report bugs and feature requests to http://bugzilla.nordugrid.org
arccat(1), arcclean(1), arccp(1), arcget(1), arcinfo(1), arckill(1), arcls(1), arcmkdir(1), arcproxy(1), arcrenew(1), arcresub(1), arcresume(1), arcrm(1), arcstat(1), arcsync(1), arctest(1)
| 2021-02-24 | NorduGrid ARC 6.10.2 |