chore(deps): bump ZB.MOM.WW.LocalDb 0.1.3 -> 0.2.1, correct the MaxBatchSize rationale

Closes the pin skew against ScadaBridge (which already pins 0.2.1). Pure pin
bump — no code change was required:

- `RegisterReplicated(string)` still delegates to `baselineExistingRows: false`,
  so `LocalDbSetup.OnReady` is byte-identical in behaviour.
- Everything 0.2.x added is additive (`DeregisterReplicated`, `MaxBatchBytes`,
  the `baselineExistingRows` overload); none of it is called here.
- The wire protocol is unchanged (0.1.x peers still sync) and the on-disk
  bookkeeping schema v1 -> v2 upgrades in place on open, so no rig, volume or
  operator action is needed.

The one thing that DID need reconciling is documentation. 0.2.0 made batching
byte-budgeted: `MaxBatchBytes` (2 MB default, under the 4 MB gRPC cap) now
bounds the wire message, and `MaxBatchSize` is demoted to a secondary row cap
plus the DB read-page size. The rig's `MaxBatchSize = 16` was chosen as a
hand-computed byte proxy ("row-count-only against gRPC's 4 MB cap"), and that
rationale is now wrong everywhere it appeared — appsettings, Configuration.md,
the pair-replication runbook, and both docker-dev site-a services.

The VALUE stays 16, for a different and still-real reason: OplogStore /
SnapshotStreamer materialise a whole read page in memory *before* the
byte-budget split runs, so 16 x ~171 KB artifact chunk rows bounds that
transient allocation at ~2.7 MB. Documented as such, with `MaxBatchBytes`
added to both config tables.

CLAUDE.md records the pin and two deliberate non-adoptions: this repo does not
take ScadaBridge's conditional-registration + boot-time `DeregisterReplicated`
self-heal (OnReady registers all four tables unconditionally, and
LocalDbSetupTests pins that set), and consequently does not use
`baselineExistingRows` either — so enabling replication on a long-running
default-OFF node converges on subsequent writes, not on rows already in the
file. Both are behaviour changes, out of scope for a pin bump.

Verification: solution builds clean; full suite run (57 projects). All 66
LocalDb tests in Host.IntegrationTests green. One unrelated failure,
RoslynVirtualTagEvaluatorTests.Evaluate_racing_ClearCompiledScripts_never_
fails_with_disposed — a Roslyn evaluator disposal race with no LocalDb in its
path, whose own comment documents that its "at most one clear per evaluation"
assumption depends on thread-pool pressure. It passed 3/3 re-runs in isolation
and fails only under full-solution parallel load; pre-existing test-design
fragility, not a regression from this bump.
This commit is contained in:
Joseph Doherty
2026-08-15 03:33:53 -04:00
parent 259d9621ba
commit a1a258d85d
6 changed files with 52 additions and 8 deletions
+2 -1
View File
@@ -364,7 +364,8 @@ replication stays inert until the sync port + peer are set.
| `LocalDb:SyncListenPort` | `0` | `0` = replication off (no sync listener). A non-zero port binds a dedicated **h2c** sync listener; set the **same** port on both pair nodes. Setting it makes the Host add an explicit Kestrel `Listen*` and re-bind the primary HTTP port (an explicit `Listen*` otherwise discards `ASPNETCORE_URLS`). |
| `LocalDb:Replication:PeerAddress` | `""` | The peer this node **dials** (`http://<peer>:<port>`). Set on the initiator only; leave empty on the passive node. The stream is bidirectional. |
| `LocalDb:Replication:ApiKey` | `""` | Bearer token for the sync stream. **Fail-closed:** no key ⇒ the passive endpoint refuses everything; a mismatch ⇒ the pair silently stops converging. **Must be byte-identical on both nodes.** Supply via `${secret:...}` / env — never a cleartext literal in production. |
| `LocalDb:Replication:MaxBatchSize` | (library default) | Rows per replication batch — **row-count-only** against gRPC's 4 MB cap. `16` for the artifact cache (chunk rows ≈171 KB, so 16 × 171 KB ≈ 2.7 MB). |
| `LocalDb:Replication:MaxBatchSize` | `500` (library) | **Secondary** row-count cap on a batch — *and* the DB read-page size. `16` on the replicating pair. Since LocalDb 0.2.0 the wire message is bounded by `MaxBatchBytes`, not by this, so it is no longer the hand-tuned byte proxy the 4 MB cap once forced. It still matters because `OplogStore.ReadBatchAboveAsync`/`SnapshotStreamer` materialise a whole read page **before** the byte-budget split runs — `16` bounds that transient allocation at ≈2.7 MB for ≈171 KB artifact chunk rows. |
| `LocalDb:Replication:MaxBatchBytes` | `2 MB` (library) | **Primary** cap on one outbound delta/snapshot message: the summed serialized size of its entries, sized under gRPC's 4 MB receive limit. Left unset across the fleet. A single row larger than the budget is sent **alone** rather than stalling the stream. Added in LocalDb 0.2.0; needs no wire change, so a node on this version interoperates with any earlier peer in both directions. |
Replication is **default-OFF** across the fleet; it is enabled per-pair as an opt-in. See
[`docs/operations/2026-07-20-localdb-pair-replication.md`](operations/2026-07-20-localdb-pair-replication.md)