Several machines, one bucket

Point each machine's config.toml (or POND_* env) at the same URL and credentials, and run pond sync on each.

Concurrent writers are safe: Lance serializes commits through the object store's conditional writes (optimistic concurrency), so two syncs at once cannot corrupt the dataset.

Within one machine, sync is single-flight: a second pond sync against the same store waits for the first (naming the holder), and the scheduled run passes --no-wait so ticks skip cleanly instead of queueing. pond status --hosts shows which machines feed the store - sessions and latest activity per ingest host.

Mixed versions

A release that changes the store schema (0.13.0 added materialized tool columns) migrates the store in place the first time the new binary opens it - a one-time backfill with a stderr notice - after which older binaries fail at open with a schema-mismatch error. When several machines share one bucket, upgrade pond on all of them together; a machine left on an older version stops syncing until it upgrades.