HTCondor
HTCondor is a free, open-source system for coordinating networked machines to run submitted computing jobs.
What HTCondor is
HTCondor is a free, open-source system for coordinating networked machines to run submitted computing jobs. It finds available machines for jobs and can restart a job elsewhere if its current machine becomes unavailable. The system can distribute large batches, including thousands of runs across multiple data sets, and make use of otherwise idle machines in a pool. ClassAds match machine resource offers with each job’s requirements and preferences. Users do not need login accounts on the machines running their jobs; HTCondor uses file transfers and split execution. It can draw on clusters, cloud resources, and international grids, while flocking can connect multiple HTCondor installations. File transfer to and from S3-compatible storage is supported, including Google Cloud Storage through its S3 interoperability API, but whole buckets or directories cannot be transferred. HTCondor includes Python bindings and provides user and administrator guides. It is licensed under Apache License 2.0. Community support is available through a mailing list; fee-based contract support offers guaranteed problem resolution and faster turnaround.
Good
- Matches jobs and machines using ClassAds.
- Can restart jobs when a machine becomes unavailable.
- Does not require job users to have machine login accounts.
- Supports S3-compatible file transfers.
- Free under Apache License 2.0.
Watch out
- Cannot transfer entire buckets or directories.
- Older LTS releases eventually stop receiving bug fixes.
- Guaranteed support requires a fee-based contract.
Who it suits
HTCondor suits academic, government, and commercial organizations managing computational workloads across networked machines. It is especially relevant when jobs can use available pool, cluster, cloud, or grid resources.
Verdict
HTCondor coordinates workloads across available computing resources and can recover jobs when a machine goes offline. Its file-transfer support has limits, and guaranteed support is a paid option.
The facts
Each one read from HTCondor's own pages, with the date it was checked.
What it does
- Access model
- HTCondor does not require users to have a login account on the machines where their jobs run, using file transfer and split execution mechanisms.checked 30 Sep 2026
- Audience
- The site says HTCSS is used by academic, government, and commercial organizations to manage computational workloads.checked 30 Sep 2026
- Cloud and grid use
- The overview says HTCondor can use clusters, cloud resources, or international grids, and the product page describes flocking multiple HTCondor installations together.checked 29 Sep 2026
- Cloud storage integration
- HTCondor supports file transfers to and from S3-compatible storage, including Google Cloud Storage through its S3 interoperability API, but does not support transferring entire buckets or directories.checked 29 Sep 2026
- Community support
- Free, community-based best-effort support is available through the htcondor-users mailing list.checked 29 Sep 2026
- Contract support
- Fee-based internal support offers guaranteed problem resolution, faster turnaround, telephone access, and a high-priority email address.checked 29 Sep 2026
- Documentation
- The site provides user and administrator quick-start guides and a manual that can be viewed online or downloaded.checked 30 Sep 2026
- Execution model
- HTCondor can run jobs without requiring users to have login accounts on the machines where the jobs run.checked 29 Sep 2026
- HTCondor-CE integration
- HTCondor-CE supports Grid Engine, HTCondor, LSF, PBS Pro, Torque, and Slurm as local batch systems.checked 30 Sep 2026
- Job scheduling
- Users submit jobs to HTCondor, which finds available machines and starts running the jobs there.checked 30 Sep 2026
- License
- HTCondor Software Suite is licensed under Apache License, Version 2.0.checked 29 Sep 2026
- Purpose
- HTCondor creates a High-Throughput Computing environment by using the computing power of networked machines, clusters, cloud resources, and international grids.checked 30 Sep 2026
- Python
- The site says HTCondor comes with Python bindings.checked 30 Sep 2026
- Recovery
- If a machine running a job becomes unavailable, HTCondor can automatically restart the job on another machine.checked 30 Sep 2026
- Release channels
- The download page describes feature releases for new features and bug fixes, and LTS releases for bug fixes to a fixed feature set.checked 30 Sep 2026
- Resource matching
- HTCondor uses ClassAds to match and rank resource offers against job requests, considering resource properties and priority values.checked 30 Sep 2026
- Scale
- The overview describes using HTCondor to submit many jobs at once, including thousands of runs across multiple data sets.checked 29 Sep 2026
- Security support
- HTCondor provides security fixes for the current feature version and current LTS version, and supports the previous LTS for approximately twelve months after a new LTS release.checked 30 Sep 2026
- Security updates
- The security page says fixes are provided for the current feature and LTS versions and, after a new LTS release, for the previous LTS version for approximately twelve months.checked 29 Sep 2026
- Upgrade limits
- The site says older LTS channels eventually stop receiving additional bug fixes and that changing to a new LTS feature set requires a manual decision.checked 30 Sep 2026
- Vulnerability reporting
- The security page asks people to report suspected or confirmed vulnerabilities to [email protected] and says the team will coordinate a disclosure timeline with the reporter.checked 30 Sep 2026
- Workload scale
- HTCondor is useful for running jobs thousands of times across different data sets, and can run jobs on otherwise idle machines in the pool.checked 30 Sep 2026
The company
- Headquarters
- Madison, Wisconsin, United Stateschecked 28 Sep 2026
Where it runs
- Platforms
- The product page says Linux, macOS, and Windows are supported.checked 29 Sep 2026
