Editing HTCondor

{{short description|High-throughput computing software}}
{{Infobox software
| name = HTCondor
| logo = 
| screenshot = 
| caption = 
| developer = [[University of Wisconsin–Madison]]
| latest release version = 24.4.0
| latest release date = {{Start date and age|2025|02|06}}
| operating system = [[Microsoft Windows]], [[Mac OS X]], [[Linux]], [[FreeBSD]]
| programming language = [[C++]], [[Python (programming language)|Python]], [[Perl]]
| genre = [[High-Throughput Computing]]
| license = [[Apache License]] 2.0
| website = {{URL|htcondor.org}}
}}

'''HTCondor''' is an [[open-source software|open-source]] [[high-throughput computing]] software framework for coarse-grained distributed parallelization of computationally intensive tasks.<ref>
{{cite journal
  | last1 = Thain    | first1 = Douglas
  | last2 = Tannenbaum | first2 = Todd
  | last3 = Livny     | first3 = Miron
  |authorlink3 = Miron Livny
  | journal = Concurrency and Computation: Practice and Experience
  | title = Distributed Computing in Practice: the Condor Experience
  | volume = 17
  | issue = 2–4
  | pages = 323–356
  | year = 2005
  | url = http://www.cs.wisc.edu/condor/doc/condor-practice.pdf
  | doi = 10.1002/cpe.938
  | citeseerx = 10.1.1.6.3035
  | s2cid = 15450656
 }}
</ref>
It can be used to manage workload on a dedicated [[Computer cluster|cluster of computers]], or to farm out work to idle desktop computers{{spaced ndash}}so-called [[CPU scavenging|cycle scavenging]].  HTCondor runs on [[Linux]], [[Unix]], [[Mac OS X]], [[FreeBSD]], and [[Microsoft Windows]] [[operating system]]s.  HTCondor can integrate both dedicated resources (rack-mounted clusters) and non-dedicated desktop machines (cycle scavenging) into one computing environment.

HTCondor is developed by the HTCondor team at the [[University of Wisconsin–Madison]] and is freely available for use.  HTCondor follows an [[open-source software|open-source]] philosophy and is licensed under the [[Apache License]] 2.0.<ref>{{cite web|url=http://research.cs.wisc.edu/htcondor/license.html|title=HTCondor - License Information|website=research.cs.wisc.edu}}</ref>

While HTCondor makes use of unused computing time, leaving computers turned on for use with HTCondor will increase energy consumption and associated costs. Starting from version 7.1.1, HTCondor can hibernate and wake machines based on user-specified policies, a feature previously available only via third-party software.

==History==
The development of HTCondor started in 1988.

HTCondor was formerly known as Condor; the name was changed in October 2012 to resolve a trademark lawsuit.<ref>{{cite web|last=Tannenbaum|first=Todd|title="Condor" name changing to "HTCondor"|url=https://lists.cs.wisc.edu/archive/htcondor-users/2012-October/msg00110.shtml|accessdate=11 March 2013}}</ref>

HTCondor was the scheduler software used to distribute jobs for the first draft assembly of the Human Genome.

==Example of use==
The [[NASA Advanced Supercomputing facility]] (NAS) HTCondor pool consists of approximately 350 [[Silicon Graphics|SGI]] and [[Sun Microsystems|Sun]] workstations purchased and used for software development, visualization, email, document preparation, and other tasks. Each workstation runs a [[daemon (computer software)|daemon]] that watches user [[input/output|I/O]] and CPU load. When a workstation has been idle for two hours, a job from the batch queue is assigned to the workstation and will run until the daemon detects a keystroke, mouse motion, or high non-HTCondor CPU usage. At that point, the job will be removed from the workstation and placed back on the batch queue.

==Features==
HTCondor can run both sequential and parallel jobs. Sequential jobs can be run in several different "universes", including "vanilla" which provides the ability to run most "batch ready" programs, and "standard universe" in which the target application is re-linked with the HTCondor I/O library which provides for remote job I/O and job checkpointing. HTCondor also provides a "local universe" which allows jobs to run on the "submit host".

In the world of parallel jobs, HTCondor supports the standard [[Message Passing Interface]] and [[Parallel Virtual Machine]] (Goux, et al. 2000) in addition to its own Master Worker "MW" library for extremely parallel tasks.

''HTCondor-G'' allows HTCondor jobs to use resources not under its direct control.
It is mostly used to talk to [[grid computing|grid]] and [[cloud computing|cloud]] resources, like pre-WS and WS Globus, [[Advanced Resource Connector|Nordugrid ARC]], [[UNICORE]] and [[Amazon Elastic Compute Cloud]].
But it can also be used to talk to other batch systems, like [[Portable Batch System|Torque/PBS]] and [[Load Sharing Facility|LSF]]. Support for [[Sun Grid Engine]] is currently under development as part of the [[European Grid Infrastructure|EGEE]] project.{{fact|date=September 2019}}

HTCondor supports the [[DRMAA]] job API. This allows DRMAA compliant clients to submit and monitor HTCondor jobs. The [[SAGA C++ Reference Implementation]] provides an HTCondor plug-in (adaptor), which makes HTCondor job submission and monitoring available via SAGA's Python and C++ APIs.

Other HTCondor features include "[[DAGMan]]" which provides a mechanism to describe job dependencies.

== See also ==
{{Portal|Free and open-source software}}
* [[List of volunteer computing projects]]
* [[Sun Grid Engine]]
* [[IBM Spectrum LSF]]
* [[High-throughput computing]]

==References==
{{Reflist}}

==External links==
* {{Official website|research.cs.wisc.edu/htcondor/}}

[[Category:Free software programmed in C++]]
[[Category:Parallel computing]]
[[Category:Grid computing]]
[[Category:Job scheduling]]