feat(remote): send read freshness headers for remote table consistency (#3439)

Closes client side work of #3370 

### Summary
- Plumbs `read_consistency_interval` from `ConnectBuilder` through
`RestfulLanceDbClient` so remote reads attach an
`x-lancedb-min-timestamp` freshness header. None = no header (default),
zero = "now", positive = `now - interval`.
- Adds per-table `FreshnessState` on `RemoteTable`: write responses
(`update`, `delete`, `merge_insert`, `add_columns`, `alter_columns`,
`drop_columns`) track the committed version, and the next read sends
`x-lancedb-min-version` so the server's cache honors read-your-write.
- `checkout(v)` / `checkout_tag(t)` / `checkout_latest()` / `restore()`
reset the freshness state appropriately; the validating `/describe/` and
tag-resolve requests are sent without freshness headers so they don't
carry stale state.
- Updates Rust, Python, and Node docstrings and calls out that stronger
consistency raises per-read latency and cost.

### Testing
- Unit tests cover default behavior, interval=0, positive interval,
checkout_latest baseline, min_version-after-write, checkout clears
state, and the two no-stale-header invariants on `checkout(v)` and
`checkout_tag(t)`.
- Ran smoke tests against local remote table to verify functionality
This commit is contained in:
Brendan Clement
2026-05-26 13:38:07 -07:00
committed by GitHub
parent df2b6d3dd4
commit 15e75804c4
9 changed files with 621 additions and 101 deletions

View File

@@ -70,16 +70,20 @@ client used by manifest-enabled native connections.
optional readConsistencyInterval: number;
```
(For LanceDB OSS only): The interval, in seconds, at which to check for
updates to the table from other processes. If None, then consistency is not
checked. For performance reasons, this is the default. For strong
consistency, set this to zero seconds. Then every read will check for
updates from other processes. As a compromise, you can set this to a
non-zero value for eventual consistency. If more than that interval
has passed since the last check, then the table will be checked for updates.
Note: this consistency only applies to read operations. Write operations are
The interval, in seconds, at which to check for updates to the table
from other processes. If None, then consistency is not checked. For
performance reasons, this is the default. For strong consistency, set
this to zero seconds. Then every read will check for updates from other
processes. As a compromise, you can set this to a non-zero value for
eventual consistency. If more than that interval has passed since the
last check, then the table will be checked for updates. Note: this
consistency only applies to read operations. Write operations are
always consistent.
Stronger consistency is not free. The smaller the interval, the more
often each read pays the cost of checking for updates against object
storage, raising per-read latency and cost.
***
### region?