我的nodejs web服务出现以下错误

Question

这个错误是在我的web服务连续运行8-10个小时后出现的。

{
    "date": "Wed Sep 13 2017 21:22:25 GMT+0000 (UTC)",
    "process": {
        "pid": 24337,
        "uid": 1000,
        "gid": 1000,
        "cwd": "/path/to/my/file/",
        "execPath": "/path/to/my/nvm/.nvm/versions/node/v4.4.5/bin/node",
        "version": "v4.4.5",
        "argv": ["/path/to/my/nvm/.nvm/versions/node/v4.4.5/bin/node", "/path/to/my/file/app.js"],
        "memoryUsage": {
            "rss": 133083136,
            "heapTotal": 83753568,
            "heapUsed": 71120576
        }
    },
    "os": {
        "loadavg": [0.0029296875, 0.0146484375, 0.04541015625],
        "uptime": 397147
    },
    "trace": [{
        "column": 13,
        "file": "/path/to/my/file/node_modules/mysql/lib/protocol/Protocol.js",
        "function": "Protocol.end",
        "line": 109,
        "method": "end",
        "native": false
    }, {
        "column": 28,
        "file": "/path/to/my/file/node_modules/mysql/lib/Connection.js",
        "function": "",
        "line": 102,
        "method": null,
        "native": false
    }, {
        "column": 20,
        "file": "events.js",
        "function": "emitNone",
        "line": 72,
        "method": null,
        "native": false
    }, {
        "column": 7,
        "file": "events.js",
        "function": "Socket.emit",
        "line": 166,
        "method": "emit",
        "native": false
    }, {
        "column": 12,
        "file": "_stream_readable.js",
        "function": "endReadableNT",
        "line": 913,
        "method": null,
        "native": false
    }, {
        "column": 9,
        "file": "node.js",
        "function": "nextTickCallbackWith2Args",
        "line": 442,
        "method": null,
        "native": false
    }, {
        "column": 17,
        "file": "node.js",
        "function": "process._tickDomainCallback",
        "line": 397,
        "method": "_tickDomainCallback",
        "native": false
    }],
    "stack": ["Error: Connection lost: The server closed the connection.", "    at Protocol.end (/path/to/my/file/node_modules/mysql/lib/protocol/Protocol.js:109:13)", "    at Socket.<anonymous> (/path/to/my/file/node_modules/mysql/lib/Connection.js:102:28)", "    at emitNone (events.js:72:20)", "    at Socket.emit (events.js:166:7)", "    at endReadableNT (_stream_readable.js:913:12)", "    at nextTickCallbackWith2Args (node.js:442:9)", "    at process._tickDomainCallback (node.js:397:17)"],
    "level": "error",
    "message": "uncaughtException: Connection lost: The server closed the connection.",
    "timestamp": "2017-09-13T21:22:25.271Z"
}

找不到为什么会发生这种情况？我还检查了我的数据库是否空闲，但我的数据库是完美的，它没有空闲。那么还有什么在杀死我的节点进程呢？我已经做了几次研究，我不知道.then，我开始通过api记录请求，然后我发现了这个错误消息，这是在连续几个小时的处理之后才出现的。

Answer 1

您可以在该堆栈跟踪中看到，MySQL服务器本身正在关闭与MySQL数据库的连接。

This issue介绍了服务器可能断开连接的原因，以及如何增加MySQL服务器超时。

描述如何在您的Node.js应用程序本身中处理此特定错误事件的Here is a similar question。这对于在断开连接时动态地重新连接到MySQL服务器非常有用。

如果按照第二个链接中的示例安全地重新连接，则应该能够防止应用程序出现这些数据库超时。与简单地延长超时长度相比，这是一种更严格的解决方案，尤其是当您不必完全依赖应用程序外部的行为时。