Question

我正在尝试测试Lambda和RDS实例之间的连通性。我将它们都放在同一私有子网中，并在安全组中打开了所有端口。当我触发Lambda时，我确实看到RDS实例上打开了一个连接。但是，Lambda在4分钟40秒后超时。 PG环境变量在Lambda配置中设置。

const { Client } = require('pg');
const client = new Client();

var hello = [
  { name: 'test', description: 'testerface' }
];

exports.handler = async (event, context, callback) => {
    // Postgres Connect
    client.connect();
    const res = client.query('SELECT $1::text as message', ['Hello world!']);
    console.log(res);
    var response = {
        "statusCode": 200,
        "headers": {
            "Content-Type" : "application/json"
        },
        "body": JSON.stringify(hello),
        "isBase64Encoded": false
    };
    callback(null, response);
};

如何从Lambda的日志中获取连接的响应-甚至在响应正文中更好？

Answer 1

您需要更好地处理客户端连接。这意味着捕获客户端可能通过的任何异常并正确释放连接。这段代码会将查询的输出返回到响应主体：

const pg = require('pg')
const pool = new pg.Pool()

async function query (q) {
  const client = await pool.connect()
  let res
  try {
    await client.query('BEGIN')
    try {
      res = await client.query(q)
      await client.query('COMMIT')
    } catch (err) {
      await client.query('ROLLBACK')
      throw err
    }
  } finally {
    client.release()
  }
  return res
}

exports.handler = async (event, context, callback) => {
    try {
      const { rows } = await query("select * from pg_tables")
      console.log(JSON.stringify(rows[0]))
      var response = {
          "statusCode": 200,
          "headers": {
              "Content-Type" : "application/json"
          },
          "body": JSON.stringify(rows),
          "isBase64Encoded": false
      };
      callback(null, response);
    } catch (err) {
      console.log('Database ' + err)
      callback(null, 'Database ' + err);
    }
};

AWS Lambda NodeJS连接到RDS Postgres数据库

1 个答案: