优化：降低访问日志噪声并增加日志文件轮转

apps/backend/src/utils/logger.test.ts

@@ -77,6 +77,16 @@ test('resolveExpiredLogFilenames supports explicit retention days', () => {
   assert.deepEqual(expired, ['app-2026-04-07.log'])
 })
 
+test('resolveExpiredLogFilenames includes rotated files', () => {
+  const expired = resolveExpiredLogFilenames(
+    ['app-2026-04-14.1.log', 'app-2026-04-07.5.log', 'app-2026-04-14.log'],
+    '2026-04-14',
+    7,
+  )
+
+  assert.deepEqual(expired, ['app-2026-04-07.5.log'])
+})
+
 test('formatLogTimestamp renders readable local timestamp with timezone offset', () => {
   const rendered = formatLogTimestamp('2026-04-14T10:36:24.974Z')
   assert.match(rendered, /^\d{4}-\d{2}-\d{2} \d{2}:\d{2}:\d{2}\.\d{3} [+-]\d{2}:\d{2}$/)

apps/backend/src/utils/logger.ts

@@ -56,6 +56,11 @@ const ACTIVE_INTEGRATION_LOG_LEVEL = normalizeLogLevel(
 )
 const DEFAULT_LOG_RETENTION_DAYS = 30
 const LOG_RETENTION_DAYS = normalizeLogRetentionDays(runtimeConfig.logging?.retentionDays)
+const DEFAULT_LOG_MAX_FILE_SIZE_MB = 20
+const DEFAULT_LOG_MAX_FILES = 5
+const LOG_MAX_FILE_SIZE_BYTES =
+  normalizeLogMaxFileSizeMb(runtimeConfig.logging?.maxFileSizeMb) * 1024 * 1024
+const LOG_MAX_FILES = normalizeLogMaxFiles(runtimeConfig.logging?.maxFiles)
 const LEGACY_LOG_FILES = new Set(['app.log', 'integration.log'])
 const SENSITIVE_KEY_PATTERN =
   /token|secret|password|passwd|pwd|cookie|authorization|credential|card|cards|cardno|cardpwd|apikey|api_key|devicekey|session|x-sign|(?:^|[_-])sign(?:ature)?(?:[_-]|$)/i
@@ -181,6 +186,7 @@ function enqueueFileWrite(
   writeQueue = writeQueue
     .then(async () => {
       await fs.mkdir(LOG_DIR, { recursive: true })
+      await rotateLogFileIfNeeded(filePath, Buffer.byteLength(`${line}\n`, 'utf8'))
       await fs.appendFile(filePath, `${line}\n`, 'utf8')
       await cleanupExpiredLogsIfNeeded(dateKey)
     })
@@ -666,12 +672,78 @@ function normalizeLogRetentionDays(value: unknown): number {
   return Math.max(1, Math.floor(parsed))
 }
 
+function normalizeLogMaxFileSizeMb(value: unknown): number {
+  const parsed = Number(value)
+  if (!Number.isFinite(parsed)) {
+    return DEFAULT_LOG_MAX_FILE_SIZE_MB
+  }
+
+  return Math.max(1, Math.floor(parsed))
+}
+
+function normalizeLogMaxFiles(value: unknown): number {
+  const parsed = Number(value)
+  if (!Number.isFinite(parsed)) {
+    return DEFAULT_LOG_MAX_FILES
+  }
+
+  return Math.max(2, Math.floor(parsed))
+}
+
+async function rotateLogFileIfNeeded(filePath: string, nextLineBytes: number): Promise<void> {
+  if (!filePath.endsWith('.log') || LOG_MAX_FILE_SIZE_BYTES <= 0) {
+    return
+  }
+
+  let currentSize = 0
+  try {
+    currentSize = (await fs.stat(filePath)).size
+  } catch (error) {
+    if (isFileMissingError(error)) {
+      return
+    }
+    throw error
+  }
+
+  if (currentSize === 0 || currentSize + nextLineBytes <= LOG_MAX_FILE_SIZE_BYTES) {
+    return
+  }
+
+  for (let index = LOG_MAX_FILES - 1; index >= 1; index -= 1) {
+    await renameIfPresent(
+      rotatedLogFilePath(filePath, index),
+      rotatedLogFilePath(filePath, index + 1),
+    )
+  }
+  await renameIfPresent(filePath, rotatedLogFilePath(filePath, 1))
+}
+
+function rotatedLogFilePath(filePath: string, index: number): string {
+  return filePath.replace(/\.log$/, `.${index}.log`)
+}
+
+async function renameIfPresent(source: string, target: string): Promise<void> {
+  try {
+    await fs.rename(source, target)
+  } catch (error) {
+    if (!isFileMissingError(error)) {
+      throw error
+    }
+  }
+}
+
+function isFileMissingError(error: unknown): boolean {
+  return Boolean(error && typeof error === 'object' && 'code' in error && error.code === 'ENOENT')
+}
+
 function shouldDeleteLogFileByDate(fileName: unknown, cutoffDateKey: string): boolean {
   if (LEGACY_LOG_FILES.has(String(fileName || '').trim())) {
     return true
   }
 
-  const matched = /^([a-z0-9-]{1,40})-(\d{4}-\d{2}-\d{2})\.log$/.exec(String(fileName || '').trim())
+  const matched = /^([a-z0-9-]{1,40})-(\d{4}-\d{2}-\d{2})(?:\.\d+)?\.log$/.exec(
+    String(fileName || '').trim(),
+  )
 
   if (!matched) {
     return false