Files
orca/cloud/apps/relay/src/assignment-row-lock-order-postgres.test.ts
T
Jinwoo Hong 030a1e0c77 fix(relay): stop holding a cell row across the whole control accept (#21563)
* fix(relay): stop holding a cell row across the whole control accept

The cell accept path took the host's cell row FOR UPDATE at its first
supersession statement and held it to COMMIT across a dozen round trips,
which capped a cell far from Postgres at a couple of accepts a second.
Fold every cell-row change on the path into one conditional delta write
issued last, so the contended row is held only across the commit.

* fix(relay): give relay_cells one global row lock order, taken last

Moving the accept's cell-row write to the end of its transaction put it
after the host's relay_control_connection_reservations rows, while every
director path that reads the inventory took those rows the other way
round. Pin one order for both roles -- host rows, then the shared cell
row -- by locking the host's reservation rows before the inventory in the
nine director paths that take both, document the tiers next to
CellInventoryLockMode, and add a census that fails on a new path taking
relay_cells first.
2026-09-18 23:16:15 -04:00

139 lines
4.7 KiB
TypeScript

import { afterAll, beforeAll, describe, expect, it } from 'vitest'
import { RelayAssignmentStore } from './assignment-store.js'
import { openRelayDatabase, type RelayDatabase } from './database.js'
const databaseUrl = process.env.ORCA_RELAY_TEST_POSTGRES_URL
const describePostgres = databaseUrl ? describe : describe.skip
const cells = [
{
id: 'row-lock-order-a',
url: 'https://row-lock-order-a.example.com',
capacityRequests: 200,
connectionHardCap: 600 as const,
connectionUnobservedBound: 50
},
{
id: 'row-lock-order-b',
url: 'https://row-lock-order-b.example.com',
capacityRequests: 200,
connectionHardCap: 600 as const,
connectionUnobservedBound: 50
}
]
const userId = 'row-lock-order-user'
const hosts = ['rowlockhost00001', 'rowlockhost00002', 'rowlockhost00003', 'rowlockhost00004'].map(
(relayHostId) => ({ userId, relayHostId })
)
// Why a deadlock counter and not "it eventually succeeded": the transaction
// wrapper retries 40P01 three times, so a cycle that fires on every wave still
// reports success to the caller while burning the retry budget that turns into
// a 503 under load. PostgreSQL counts every detected cycle in pg_stat_database,
// which sees through the retry.
describePostgres('PostgreSQL row lock order', () => {
const databases: RelayDatabase[] = []
beforeAll(async () => {
for (let index = 0; index < 4; index++) {
databases.push(await openRelayDatabase({ databaseUrl, dataDir: '' }))
}
})
async function removeTestRows(database: RelayDatabase): Promise<void> {
await database.query(
`DELETE FROM relay_control_connection_reservations WHERE user_id = ?`,
[userId]
)
for (const table of [
'relay_control_capabilities',
'relay_assignment_activity_leases',
'relay_post_drain_migration_pins',
'relay_assignment_migration_incarnations',
'relay_assignment_migrations',
'relay_assignments'
]) {
await database.query(`DELETE FROM ${table} WHERE user_id = ?`, [userId])
}
for (const cell of cells) {
for (const table of [
'relay_cell_connection_snapshots',
'relay_cell_connection_runtime',
'relay_cell_connection_limits',
'relay_cell_runtime',
'relay_cells'
]) {
await database.query(`DELETE FROM ${table} WHERE cell_id = ?`, [cell.id])
}
}
}
afterAll(async () => {
if (databases[0]) await removeTestRows(databases[0])
for (const connection of databases) await connection.close()
})
async function deadlockCount(): Promise<number> {
const rows = await databases[0]!.query(
`SELECT deadlocks FROM pg_stat_database WHERE datname = current_database()`
)
return Number(rows[0]!.deadlocks)
}
it('runs the cell accept and the placement retry concurrently without a cycle', async () => {
await removeTestRows(databases[0]!)
const stores = databases.map((database) => new RelayAssignmentStore(database, () => 100))
await stores[0]!.reconcileCells(cells)
for (const cell of cells) {
await stores[0]!.recordCellHeartbeat({
cellId: cell.id,
cellUrl: cell.url,
cellIncarnation: '11111111-1111-4111-8111-111111111111',
startedAt: 50,
ready: true,
observedRequests: 0,
totalConnections: 0,
inFlightConnections: 0,
reservedConnectionUnits: 0,
enforcedConnectionUnits: 0,
connectionInclusionWatermark: 1,
connectionHardCap: 600,
connectionUnobservedBound: 50
})
}
const placements = new Map<string, { cellId: string; assignmentEpoch: number }>()
for (const identity of hosts) {
const assignment = await stores[0]!.assign(identity)
placements.set(identity.relayHostId, assignment)
}
const before = await deadlockCount()
// The accept path (host rows, then the cell row last) against the paths
// that must read the inventory first: placement and evacuation.
for (let round = 0; round < 12; round++) {
await Promise.allSettled(
hosts.flatMap((identity, index) => {
const placement = placements.get(identity.relayHostId)!
const store = stores[index % stores.length]!
const other = stores[(index + 1) % stores.length]!
return [
store.activateControl(identity, {
cellId: placement.cellId,
assignmentEpoch: placement.assignmentEpoch,
generation: round + 2
}),
other.assign(identity),
other.startEvacuation(
identity,
placement.cellId === cells[0]!.id ? cells[1]!.id : cells[0]!.id
)
]
})
)
}
const after = await deadlockCount()
expect(after - before).toBe(0)
}, 120_000)
})