Google Drive performance: ~280x faster recursive listing with OpenDAL batch queries

[mro68]

Summary

OpenDAL's Google Drive backend now supports efficient batch recursive listing, improving performance by ~280x compared to the previous implementation. This issue tracks when rustic_core can benefit from this improvement.

Problem

When using rustic with Google Drive via OpenDAL (opendal:gdrive), operations like repoinfo, check, or backup were extremely slow compared to using rclone:gdrive.

Root cause: OpenDAL's generic FlatLister made one API call per directory. For a repository with 256 data/XX/ subdirectories + other dirs, this meant ~260+ sequential API calls.

Solution (implemented in OpenDAL)

A custom GdriveFlatLister was implemented that uses Google Drive's OR query syntax to batch multiple directory lookups:

('id1' in parents or 'id2' in parents or 'id3' in parents ...)

This is the same approach rclone uses for its ListR implementation.

Performance Results

Tested with rustic repoinfo against a real Google Drive repository (~2100 files, 130 GiB):

Metric	Before	After	Improvement
Scanning time	14 minutes	3 seconds	~280x faster
API calls	~260+	~12	~20x fewer

Dependencies

This improvement requires two OpenDAL PRs to be merged and released:

1. fix(services/gdrive): include size and modifiedTime in list() metadata apache/opendal#7058 - fix(services/gdrive): include size and modifiedTime in list() metadata

   • Required for rustic to work at all (without this, file sizes are missing)

2. feat(services/gdrive): implement batch recursive listing for ~200x performance improvement apache/opendal#7059 - feat(services/gdrive): implement batch recursive listing

   • The performance improvement itself

Timeline

1. ⏳ Wait for OpenDAL PRs to be reviewed and merged
2. ⏳ Wait for OpenDAL release (0.55.1 or 0.56.0)
3. 🔧 Update rustic_core's OpenDAL dependency (see Update OpenDAL integration for 0.55+ (Scheme enum removed) #442 for API changes needed)
4. ✅ Benefit from improved Google Drive performance

Related Issues

• Update OpenDAL integration for 0.55+ (Scheme enum removed) #442 - OpenDAL 0.55+ API changes (Scheme enum removed)
• bug: services/gdrive: list() returns size=0 for all files - missing size field in API call and metadata mapping apache/opendal#7057 - Original bug report for missing metadata
• fix(services/gdrive): include size and modifiedTime in list() metadata apache/opendal#7058 - PR fixing metadata
• feat(services/gdrive): implement batch recursive listing for ~200x performance improvement apache/opendal#7059 - PR for batch listing performance

Notes

For users who need this fix now, you can use a patched OpenDAL version by adding to your Cargo.toml:

[patch.crates-io]
opendal = { git = "https://github.com/mro68/opendal", branch = "feat/gdrive-batch-recursive-listing" }

This branch includes both the metadata fix and the performance improvement.

[aawsome]

Hi @mro68!
Thanks a lot for the summary! We'll wait for the next opendal release and update the version then ASAP.

[mro68]

Hi @aawsome — thanks for the quick triage!

FYI: both OpenDAL PRs (#7058 and #7059) have been merged and OpenDAL v0.55 includes the metadata fix (size in list()) and the batch recursive listing improvement. You can bump the opendal dependency to 0.55 now (see also #442 for the small API changes).

If helpful, I can open a PR that:

• updates opendal → 0.55,
• applies the API adjustments from Update OpenDAL integration for 0.55+ (Scheme enum removed) #442 (Scheme enum removal), and
• adds a small integration test to prevent regressions.

Shall I prepare that PR?

[aawsome]

Hi @mro68 - we are already at opendal 0.55 (updated in #446) - but I fear that this does not yet include the two fixes you have mentioned.
I think we just wait for opendal 0.55.1 or 0.56 (whatever the name will be) and then simply bump the dependency version...

[mro68]

Status Update

Both OpenDAL PRs have been merged ✅

PR	Status	Merged
apache/opendal#7058 - size/modifiedTime metadata fix	✅ Merged	2025-12-18
apache/opendal#7059 - batch recursive listing	✅ Merged	2025-12-19

Next Steps

1. ⏳ Waiting for OpenDAL release - Current release is v0.55.0 (2025-11-24). These changes will be included in the next release (likely v0.56.0).
2. 🔧 Once released, bump OpenDAL dependency in rustic_core to pick up the GDrive improvements.

I've set up release notifications on the OpenDAL repo and will follow up here when v0.56.0 is available.