Cutover Workflow

A live migration doesn't have a single point where it's "done." Once it's caught up and verified, there's a defined path from there to actually cutting over, instead of a migrate run you either trust blindly or don't run at all.

Status

Every migration (a --from/--to pair) has a persisted operational status, alongside its checkpoint: not_started, syncing, paused, verified, cut_over, rolled_back, or cancelled.

vecparity migrate status --from pgvector://docs --to qdrant://docs

Pause and resume

vecparity migrate pause --from pgvector://docs --to qdrant://docs

This is cooperative, not a kill signal: a running migrate run --live process checks for a pause request once per poll and stops cleanly, checkpointing first. There's no separate daemon process to signal directly, so this only takes effect while a --live run is actually in progress; otherwise it just records the request until the next run.

Resuming is just re-running migrate run (without --fresh); it picks up from the checkpoint automatically.

Cancel

vecparity migrate cancel --from pgvector://docs --to qdrant://docs

Marks the migration cancelled. The checkpoint itself isn't deleted (use vecparity checkpoint clear for that); a future migrate run refuses to resume a cancelled migration unless you pass --fresh.

Cutover

vecparity cutover --from pgvector://docs --to qdrant://docs \
    --queries golden_queries.json --min-recall 0.95

Runs one final sync pass to close any last gap, then a final parity check. The migration is only marked cut_over if that check passes; if it fails, the command exits non-zero and the migration's status is left as-is.

Rollback

vecparity rollback --from pgvector://docs --to qdrant://docs

Marks a cut-over migration rolled back.

What this doesn't do: vecparity has no way to redirect your application's traffic, and rollback doesn't sync data back to the source, it isn't a two-way replication tool. Both commands track state and give you evidence, a real final parity check, for a decision you still make and act on yourself.