Storage schema upgrade failure involving LevelDB prevents Atom from starting

Question

Storage schema upgrade failure involving LevelDB prevents Atom from starting
When Atom encounters a storage schema version mismatch at startup, it runs a migration script; if the script throws an exception, the process aborts and the storage database is left in a partially migrated state, blocking further launches until the user manually deletes or repairs the storage directory.
This behavior leaves no automatic rollback, risks loss of window state and workspace layouts, and raises the question of whether a versioned backup‑and‑restore strategy should be introduced for storage migrations.

Should Atom implement a versioned backup‑and‑restore mechanism for storage migrations?
What degree of automation is acceptable for rolling back a failed migration?
How can Atom verify migration success before committing the schema change?

Tasadduq Burney · Answer

Yes. Atom should implement a versioned backup-and-restore mechanism for LevelDB storage migrations, with fully automatic rollback that is transparent to the user.
Confirmed facts

On startup with a storage schema version mismatch, Atom runs a migration script.
If the script throws, the process aborts and the storage database is left in a partially migrated state.
Further launches are blocked until the user manually deletes or repairs the storage directory.
There is currently no automatic rollback and window state and workspace layouts can be lost.

Likely explanation
The migration is applied in place to the live LevelDB directory without a transactional snapshot or pre-migration copy. An exception during the in-place write therefore leaves the store in an inconsistent state that persists across restarts.
Steps needed for this case

Before migration, with Atom not running, copy the entire LevelDB storage directory to a versioned backup folder named by the source schema version and timestamp.
Run the migration against the live directory inside a try block.
On success, verify migration before committing: open the database, confirm the schema version key is updated to the target version, and perform a lightweight integrity read of critical keys such as window state and workspace layout.
If verification passes, allow startup to continue and schedule cleanup of old backups after a successful launch.
If migration throws or verification fails, restore the LevelDB directory from the versioned backup, retain the failed migration artifacts for limited-time diagnostics, and allow startup to proceed with the previous schema.

Automation should be full and transparent: copy before change, restore automatically on error, and only remove the backup after verified success. Do not delete failed artifacts immediately.
One diagnostic detail that changes the recommendation: does the storage layer already perform an atomic filesystem snapshot outside the application? If an external atomic snapshot is guaranteed, an in-app backup may be redundant. Confirm whether such a snapshot exists before adding duplicate copy logic.

Storage schema upgrade failure involving LevelDB prevents Atom from starting

Storage schema upgrade failure involving LevelDB prevents Atom from starting

1 answer

Confirmed facts

Likely explanation

Steps needed for this case

Your perspective belongs here.

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