Commit 8aa5be2f02c3b4b9b5b3b86acbf5f2b0467438f4 | the-knife

author	Theo Browne <me@t3.gg> 2026-09-25 19:28:02-07:00
committer	GitHub <noreply@github.com> 2026-09-25 19:28:02-07:00
log	8aa5be2f02c3b4b9b5b3b86acbf5f2b0467438f4
tree	3f4e87fcc78c144a11ec954447a647962f380eaa
parent	7c901a37c4e8f35c408a27dbd1bd2efea06a74f5
signature	Signed by PGP key B5690EEEBB952194

fix(server): the SQLite WAL file shrinks back after large writes (#13684)

Co-authored-by: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

2 files changed, 37 insertions(+), 1 deletions(-)

apps
- server
  - src
    persistence
    Layers
    Sqlite.test.ts
    Sqlite.ts

apps/server/src/persistence/Layers/Sqlite.test.ts+31-1

...	@@ -10,7 +10,11 @@ import * as Effect from "effect/Effect";	...	@@ -10,7 +10,11 @@ import * as Effect from "effect/Effect";
10	import * as Layer from "effect/Layer";	10	import * as Layer from "effect/Layer";
11	import * as SqlClient from "effect/unstable/sql/SqlClient";	11	import * as SqlClient from "effect/unstable/sql/SqlClient";
12		12
13	import { SqlitePersistenceMemory, makeSqlitePersistenceLive } from "./Sqlite.ts";	13	import {
		14	SqlitePersistenceMemory,
		15	WAL_SIZE_LIMIT_BYTES,
		16	makeSqlitePersistenceLive,
		17	} from "./Sqlite.ts";
14		18
15	const lockHolderSource = `	19	const lockHolderSource = `
16	const { DatabaseSync } = require("node:sqlite");	20	const { DatabaseSync } = require("node:sqlite");
...	@@ -57,6 +61,32 @@ it.effect("waits out a concurrent writer instead of failing with SQLITE_BUSY", (	...	@@ -57,6 +61,32 @@ it.effect("waits out a concurrent writer instead of failing with SQLITE_BUSY", (
57	);	61	);
58	});	62	});
59		63
		64	it.effect("shrinks the WAL file back to the size limit after a large write", () => {
		65	const tempDir = NodeFS.mkdtempSync(NodePath.join(NodeOS.tmpdir(), "t3-sqlite-wal-"));
		66	const dbPath = NodePath.join(tempDir, "state.sqlite");
		67	const walFileSize = () => NodeFS.statSync(`${dbPath}-wal`).size;
		68	// About 25% more 4 KB rows than the limit holds, in one transaction.
		69	const rowCount = Math.ceil((WAL_SIZE_LIMIT_BYTES * 1.25) / 4000);
		70
		71	return Effect.gen(function* () {
		72	const sql = yield* SqlClient.SqlClient;
		73	yield* sql`CREATE TABLE wal_probe(payload BLOB)`;
		74	yield* sql`
		75	WITH RECURSIVE n(i) AS (SELECT 1 UNION ALL SELECT i + 1 FROM n WHERE i < ${rowCount})
		76	INSERT INTO wal_probe(payload) SELECT randomblob(4000) FROM n
		77	`;
		78	assert.isAbove(walFileSize(), WAL_SIZE_LIMIT_BYTES);
		79
		80	// The auto-checkpoint after the large commit copied every frame into the
		81	// database, so the next commit restarts the WAL and cuts the file back.
		82	yield* sql`INSERT INTO wal_probe(payload) VALUES (x'00')`;
		83	assert.isAtMost(walFileSize(), WAL_SIZE_LIMIT_BYTES);
		84	}).pipe(
		85	Effect.provide(makeSqlitePersistenceLive(dbPath).pipe(Layer.provide(NodeServices.layer))),
		86	Effect.ensuring(Effect.sync(() => NodeFS.rmSync(tempDir, { recursive: true, force: true }))),
		87	);
		88	});
		89
60	it.effect("applies busy_timeout in the shared persistence setup", () =>	90	it.effect("applies busy_timeout in the shared persistence setup", () =>
61	Effect.gen(function* () {	91	Effect.gen(function* () {
62	const sql = yield* SqlClient.SqlClient;	92	const sql = yield* SqlClient.SqlClient;

apps/server/src/persistence/Layers/Sqlite.ts+6

 @@ -8,6 +8,9 @@ import * as NodeSqliteClient from "@t3tools/shared/nodeSqliteClient";
 import { runMigrations } from "../Migrations.ts";
 import { ServerConfig } from "../../config.ts";
+// Size the -wal file is cut back to on the first commit after a WAL reset.
+export const WAL_SIZE_LIMIT_BYTES = 32 * 1024 * 1024;
 const setup = Layer.effectDiscard(
   Effect.gen(function* () {
     const sql = yield* SqlClient.SqlClient;
 @@ -15,6 +18,9 @@ const setup = Layer.effectDiscard(
     yield* sql`PRAGMA busy_timeout = 5000;`;
     yield* sql`PRAGMA foreign_keys = ON;`;
     yield* sql`PRAGMA journal_mode = WAL;`;
+    // PASSIVE checkpoints never shrink the -wal file, so it otherwise keeps its
+    // largest size until the last connection closes.
+    yield* sql.unsafe(`PRAGMA journal_size_limit = ${WAL_SIZE_LIMIT_BYTES};`);
     yield* runMigrations();
   }),
 );