log service in db

db/log_client.py

@@ -0,0 +1,152 @@
+"""
+统一日志客户端 — 各服务共用。
+
+设计要点：
+  - 使用 urllib.request（标准库，不引入 requests）
+  - 异步非阻塞：内存队列 + 后台线程批量推送，不拖慢业务
+  - fail-safe：db 服务不可用时静默丢弃，绝不影响业务
+  - 缓冲批量：队列满 50 条或超时 2 秒时自动 flush
+
+用法：
+    from log_client import logs
+
+    logs.info("dnfs", "节点新增成功 id=42")
+    logs.error("dnfs", "数据库连接失败", extra={"errno": 2002})
+    logs.push("gateway", "WARNING", "登录失败次数超限",
+              trace_id="req-abc", extra={"ip": "1.2.3.4"})
+"""
+
+import json
+import threading
+import queue
+import time
+import urllib.request
+import urllib.error
+import atexit
+
+# ── 配置 ──────────────────────────────────────────────────────────────
+
+DB_LOG_URL = 'http://127.0.0.1:8005/log/ingest'
+
+_BATCH_SIZE = 50         # 队列满 50 条时 flush
+_FLUSH_INTERVAL = 2.0    # 超时 2 秒强制 flush
+_TIMEOUT = 5             # HTTP 请求超时（秒）
+
+
+class LogClient:
+    """异步批量日志推送客户端。"""
+
+    def __init__(self, url=DB_LOG_URL, batch_size=_BATCH_SIZE,
+                 flush_interval=_FLUSH_INTERVAL):
+        self._url = url
+        self._batch_size = batch_size
+        self._flush_interval = flush_interval
+        self._queue = queue.Queue()
+        self._stop = threading.Event()
+        self._thread = threading.Thread(target=self._flush_loop,
+                                        daemon=True, name='log-client')
+        self._thread.start()
+        atexit.register(self._shutdown)
+
+    # ── 公开接口 ────────────────────────────────────────────────────────
+
+    def push(self, service, level, message, trace_id=None, extra=None):
+        """推送一条日志（非阻塞，立即返回）。"""
+        self._queue.put({
+            'service': service,
+            'level': level,
+            'message': message,
+            'trace_id': trace_id,
+            'extra': extra,
+        })
+
+    def debug(self, service, message, **kw):
+        self.push(service, 'DEBUG', message, **kw)
+
+    def info(self, service, message, **kw):
+        self.push(service, 'INFO', message, **kw)
+
+    def warning(self, service, message, **kw):
+        self.push(service, 'WARNING', message, **kw)
+
+    def error(self, service, message, **kw):
+        self.push(service, 'ERROR', message, **kw)
+
+    def critical(self, service, message, **kw):
+        self.push(service, 'CRITICAL', message, **kw)
+
+    def flush(self):
+        """手动 flush 队列中剩余的日志。"""
+        batch = []
+        while True:
+            try:
+                batch.append(self._queue.get_nowait())
+                if len(batch) >= self._batch_size:
+                    self._send(batch)
+                    batch = []
+            except queue.Empty:
+                break
+        if batch:
+            self._send(batch)
+
+    # ── 内部实现 ────────────────────────────────────────────────────────
+
+    def _flush_loop(self):
+        """后台线程：积攒到 batch_size 或超时 flush_interval 时发送。"""
+        batch = []
+        last_flush = time.monotonic()
+
+        while not self._stop.is_set():
+            timeout = max(0, self._flush_interval - (time.monotonic() - last_flush))
+            try:
+                item = self._queue.get(timeout=timeout)
+                batch.append(item)
+                # 继续非阻塞地取，直到满 batch_size
+                while len(batch) < self._batch_size:
+                    try:
+                        batch.append(self._queue.get_nowait())
+                    except queue.Empty:
+                        break
+            except queue.Empty:
+                pass  # 超时，没有新日志
+
+            # 满了或超时了就发
+            should_flush = (
+                len(batch) >= self._batch_size or
+                (batch and time.monotonic() - last_flush >= self._flush_interval)
+            )
+            if should_flush:
+                self._send(batch)
+                batch = []
+                last_flush = time.monotonic()
+
+        # 退出前 flush 剩余
+        if batch:
+            self._send(batch)
+
+    def _send(self, batch):
+        """发送一批日志到 db 服务。失败时静默丢弃。"""
+        data = json.dumps({'logs': batch}).encode('utf-8')
+        req = urllib.request.Request(
+            self._url, data=data,
+            headers={'Content-Type': 'application/json'},
+            method='POST'
+        )
+        try:
+            with urllib.request.urlopen(req, timeout=_TIMEOUT) as resp:
+                resp.read()  # 消费响应体
+        except (urllib.error.URLError, urllib.error.HTTPError, OSError):
+            # fail-safe：日志服务不可用，静默丢弃，不影响业务
+            pass
+        except Exception:
+            pass
+
+    def _shutdown(self):
+        """进程退出时 flush 剩余日志。"""
+        self._stop.set()
+        self.flush()
+
+
+# ── 全局单例 ──────────────────────────────────────────────────────────
+
+logs = LogClient()