This document provides an overview of the iRODS Globus Connector, which allows data stored in iRODS to be accessed via the Globus data transfer service. It discusses how the connector implements the Globus plugin interface to perform operations like file transfers, checksum validation, and directory listings. Recent enhancements to the connector include migrating the code to C++, improving checksum calculation, and multithreaded transfers to boost performance up to 555 MiB/s for downloads. The connector provides a way to integrate iRODS storage with the Globus ecosystem for secure collaboration and data sharing across organizational boundaries.

1. iRODS Globus Connector
iRODS Globus Connector
Justin James
Applications Engineer
iRODS Consortium
May 11, 2022
GlobusWorld 2022
Chicago, IL and Virtual
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2. Quick iRODS Overview
iRODS - Integrated Rule Oriented Data System
Open source
Distributed
Metadata Driven
A flexible framework for the abstraction of infrastructure
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3. iRODS as the Integration Layer
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4. iRODS Overview - Data Virtualization
Logical Path
Physical Path(s)
- POSIX file systems
- Object Stores (S3)
- Tape
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5. iRODS Overview - Data Discovery
Attach metadata to any first class entity
within the iRODS Zone
Data Objects
Collections
Users
Storage Resources
The Namespace
iRODS provides automated and user-provided
metadata which makes your data and infrastructure
more discoverable, operational and valuable.
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6. Metadata Everywhere
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7. iRODS Overview - Workflow Automation
Integrated scripting language which is triggered
by any operation within the framework
Authentication
Storage Access
Database Interaction
Network Activity
Extensible RPC API
The iRODS rule engine provides the ability to capture real world
policy as computer actionable rules which may allow, deny, or
add context to operations within the system.
Rules can be written in C++, Python, or the native rule language.
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8. Dynamic Policy Enforcement Points
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9. Secure Collaboration
iRODS allows for collaboration across
administrative boundaries after deployment
No need for common infrastructure
No need for shared funding
Affords temporary collaborations
iRODS provides the ability to federate namespaces across
organizations without pre-coordinated funding or effort.
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10. iRODS Globus Connector - Overview
Provides access to iRODS storage resources from a Globus Connect Server
iRODS appears as a filesystem to Globus despite the storage type used underneath
Based on work from EUDAT
European Data Collaborative with enhancements by UNC/RENCI and our Globus partners
The connector is a plugin for the Globus Connect Server and a client to the iRODS servers
All Globus requests use the iRODS C++ client API to get information and transfer data to iRODS
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11. iRODS Globus Connector - Globus Plugin Interface
The iRODS Globus Connector implements the globus_gfs_storage_iface_t interface.
The connector implements the following interface functions:
INIT - Called when a new session is initiated. Reads the user environment and calls clientLogin().
DESTROY - Called at the end of the session. Cleans up and calls rcDisconnect().
SEND - Called when client requests to receive a file. Calls rcDataObjRead().
RECEIVE - Called when client requests to transfer a file to the server. Calls rcDataObjWrite().
COMMAND - Called when a client sends a command to the server (see next slide).
STAT - Called when the server needs information about the file. Calls rcObjStat().
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12. iRODS Globus Connector - Globus Client Commands
The following client commands are implemented:
GLOBUS_GFS_CMD_MKD - Creates a collection in iRODS. Calls rcCollCreate().
GLOBUS_GFS_CMD_RMD - Removes a collection. Calls rcRmColl().
GLOBUS_GFS_CMD_DELE - Deletes an object. Calls rcDataObjUnlink().
GLOBUS_GFS_CMD_CKSM - Gets the checksum for an object (see next slide).
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13. iRODS Globus Connector - Recent Enhancements / Fixes
Migrated the code from C to C++.
Used RAII concepts for memory and resource cleanup.
Changed how file hashing works (see next slide).
Improved upload and download performance (see last slide).
Support incremental directory listings for very large directories.
After either X number of entries are encountered or Y seconds have passed since the last partial
listing, send additional entries via globus_gridftp_server_finished_stat_partial().
Implemented heartbeats for long running checksum operations.
Implemented the realpath feature so that alternate paths don't allow users to bypass path restrictions.
Fixed some memory leaks in existing code and other minor bug fixes / performance improvements.
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14. iRODS Globus Connector - Checksum/Hashing
Original implementation relied on the default hashing scheme in iRODS.
iRODS only supports MD5 and SHA256 and the algorithm used is system wide.
To support client-requested hashing and a larger set of hashing algorithms, the hash files are now
calculated by the iRODS Globus Connector and stored in metadata as follows:
AVU Name - Globus::<algorithm>
AVU Value - <checksum value>
AVU Units - epoch time when the checksum was calculated
If the file has been updated since the last hash has been calculated, a new hash will be calculated.
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15. iRODS Globus Connector - File Transfer Improvements
The original connector did not use multithreaded transfers and had some
performance bottlenecks.
iRODS mechanism for multithreaded transfer differs from Globus.
To implement multithreaded transfers, the iRODS Globus Connector needed to
bridge these two methodologies.
Average performance comparison for a 5G file using 3 threads using local storage:
Upload - Improved from 31.6 seconds to 9.9 seconds!
Download - Improved from 28 seconds to 11 seconds!
Download performance peaked at 555 MiB/s (9 seconds) using six threads.
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16. Questions?
Thank you!
Justin James
Applications Engineer
iRODS Consortium
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