{"id":23278491,"url":"https://github.com/hdfgroup/vol-log-based","last_synced_at":"2026-03-04T08:03:02.589Z","repository":{"id":37384160,"uuid":"361057404","full_name":"HDFGroup/vol-log-based","owner":"HDFGroup","description":"Log VOL - an HDF5 VOL connector for storing data in a time-log layout in files","archived":false,"fork":false,"pushed_at":"2025-02-20T03:37:29.000Z","size":3757,"stargazers_count":3,"open_issues_count":9,"forks_count":7,"subscribers_count":6,"default_branch":"master","last_synced_at":"2026-01-02T12:36:34.699Z","etag":null,"topics":["hdf5","hpc","mpi","parallel-io","vol"],"latest_commit_sha":null,"homepage":"","language":"C++","has_issues":true,"has_wiki":null,"has_pages":null,"mirror_url":null,"source_name":null,"license":"other","status":null,"scm":"git","pull_requests_enabled":true,"icon_url":"https://github.com/HDFGroup.png","metadata":{"files":{"readme":"README.md","changelog":null,"contributing":null,"funding":null,"license":null,"code_of_conduct":null,"threat_model":null,"audit":null,"citation":null,"codeowners":null,"security":null,"support":null,"governance":null,"roadmap":null,"authors":null,"dei":null,"publiccode":null,"codemeta":null,"zenodo":null}},"created_at":"2021-04-24T03:01:30.000Z","updated_at":"2025-09-08T20:35:59.000Z","dependencies_parsed_at":"2023-02-14T03:01:20.924Z","dependency_job_id":"31a74bba-da84-47b7-bd7b-30a028f49fdb","html_url":"https://github.com/HDFGroup/vol-log-based","commit_stats":{"total_commits":1013,"total_committers":7,"mean_commits":"144.71428571428572","dds":0.3879565646594274,"last_synced_commit":"e3cb362c05e61722f6854d54b14270b33ec7c49a"},"previous_names":["hdfgroup/vol-log-based","datalib-ecp/vol-log-based"],"tags_count":5,"template":false,"template_full_name":null,"purl":"pkg:github/HDFGroup/vol-log-based","repository_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/HDFGroup%2Fvol-log-based","tags_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/HDFGroup%2Fvol-log-based/tags","releases_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/HDFGroup%2Fvol-log-based/releases","manifests_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/HDFGroup%2Fvol-log-based/manifests","owner_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners/HDFGroup","download_url":"https://codeload.github.com/HDFGroup/vol-log-based/tar.gz/refs/heads/master","sbom_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/HDFGroup%2Fvol-log-based/sbom","scorecard":null,"host":{"name":"GitHub","url":"https://github.com","kind":"github","repositories_count":286080680,"owners_count":30075922,"icon_url":"https://github.com/github.png","version":null,"created_at":"2022-05-30T11:31:42.601Z","updated_at":"2026-03-04T08:01:56.766Z","status":"ssl_error","status_checked_at":"2026-03-04T08:00:42.919Z","response_time":59,"last_error":"SSL_connect returned=1 errno=0 peeraddr=140.82.121.5:443 state=error: unexpected eof while reading","robots_txt_status":"success","robots_txt_updated_at":"2025-07-24T06:49:26.215Z","robots_txt_url":"https://github.com/robots.txt","online":false,"can_crawl_api":true,"host_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub","repositories_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories","repository_names_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repository_names","owners_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners"}},"keywords":["hdf5","hpc","mpi","parallel-io","vol"],"created_at":"2024-12-19T22:31:56.687Z","updated_at":"2026-03-04T08:03:02.573Z","avatar_url":"https://github.com/HDFGroup.png","language":"C++","funding_links":[],"categories":[],"sub_categories":[],"readme":"## Log VOL - an HDF5 VOL connector for storing data in a time-log layout in files\n\nThis software repository contains source codes implementing Log VOL connector, an\n[HDF5](https://www.hdfgroup.org) Virtual Object Layer\n([VOL](https://portal.hdfgroup.org/display/HDF5/Virtual+Object+Layer)) plugin\nthat stores HDF5 datasets in a storage layout similar to the time log. When using\nthe Log VOL connector, write requests from an MPI process are appended one after\nanother (as logs) in a contiguous space in the file. The contiguous spaces of\nmultiple processes are appended one after another following the increasing order\nof processes' MPI rank IDs. Such a log layout I/O strategy avoids the expensive\ninter-process communication required when storing data in the canonical order.\nOne of the pwoerful features of HDF5 VOL is to allow applications to make use\na VOL connector by setting two environment variables without changing the\napplication source codes. Using the Log VOL connector, exist HDF5 programs can\nachieve a better parallel write performance with no changes to their codes.\nFiles created by the Log VOL conform with the HDF5 file format specification,\nbut require the Log VOL to read them back.\n\n* Current build status:\n  * [![Ubuntu_mpich](https://github.com/HDFGroup/vol-log-based/actions/workflows/ubuntu_mpich.yml/badge.svg)](https://github.com/HDFGroup/vol-log-based/actions/workflows/ubuntu_mpich.yml)\n  * [![Ubuntu with OpenMPI](https://github.com/HDFGroup/vol-log-based/actions/workflows/ubuntu_openmpi.yml/badge.svg)](https://github.com/HDFGroup/vol-log-based/actions/workflows/ubuntu_openmpi.yml)\n  * [![Mac with MPICH](https://github.com/HDFGroup/vol-log-based/actions/workflows/mac_mpich.yml/badge.svg)](https://github.com/HDFGroup/vol-log-based/actions/workflows/mac_mpich.yml)\n\n### HDF5 VOL Connector ID\n* This Log VOL connector has been registered with the HDF group with\n  [Connector Identifier 514](https://support.hdfgroup.org/documentation/hdf5-docs/registered_vol_connectors.html).\n \n### Documents\n* [doc/userguide.md](doc/userguide.md) contains the compile and run instructions.\n* [doc/design.md](doc/design.md) outlines the design of Log VOL connector.\n* [doc/api.md](doc/api.md) describes the new APIs introduced in this VOL.\n\n### Application Case Studies and Experimental Results\n* [E3SM I/O case study](case_studies/E3SM_IO.md) - Energy Exascale Earth System Model ([E3SM](https://github.com/E3SM-Project/E3SM)).\n* [WRF I/O case study](case_studies/WRF.md) - Weather Research and Forecasting Model ([WRF](https://github.com/wrf-model/WRF)).\n\n### Developers\n* Wei-keng Liao \u003c\u003cwkliao@northwestern.edu\u003e\u003e\n* Kai-yuan Hou \u003c\u003ckai-yuanhou2020@u.northwestern.edu\u003e\u003e\n* Zanhua Huang \u003c\u003czanhua@u.northwestern.edu\u003e\u003e\n\nCopyright (C) 2022, Northwestern University.\nSee [COPYRIGHT](COPYRIGHT) notice in top-level directory.\n\n### Project funding supports:\nOngoing development and maintenance of the Log VOL connector are supported by the\nExascale Computing Project (17-SC-20-SC), a joint project of the U.S.\nDepartment of Energy's Office of Science and National Nuclear Security\nAdministration, responsible for delivering a capable exascale ecosystem,\nincluding software, applications, and hardware technology, to support the\nnation's exascale computing imperative.\n\n","project_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Fhdfgroup%2Fvol-log-based","html_url":"https://awesome.ecosyste.ms/projects/github.com%2Fhdfgroup%2Fvol-log-based","lists_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Fhdfgroup%2Fvol-log-based/lists"}