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我有一个C＃Lambda函数，它在第一次执行时起作用，但在第二次执行时失败。 我创建了一些日志来帮助我排查问题出在哪里，但我正在努力弄清楚实际发生的事情。AWS Lambda函数在第一次运行时工作，但不是第二次
首先执行日志：
START RequestId: XXXXXXXXXXXXXXXXXXXXXXXXXXXXX Version: $LATEST
1. Connecion to Database is Open
2. Running Query: SELECT * FROM Employee3
3. Returning Results
4. Close connection
5. Close reader
6. Dispose cmd
7. Configure encoding and string to stream
END RequestId: XXXXXXXXXXXXXXXXXXXXXXXX
REPORT RequestId: XXXXXXXXXXXXXXXXXXXXXXXX Duration: 10097.73 ms Billed Duration: 10100 ms Memory Size: 128 MB Max Memory Used: 41 MB
响应：（我知道这是不是有效的JSON，这我最终的目标，但是这将是下一个项目我解决，一旦我算出这个 ）
Connecion to Database is Open
Joe
Bob
Mary
第二次执行日志：
START RequestId: XXXXXXXXXXXXXXXXXXXXXXXXXXXXX Version: $LATEST
1. Connecion to Database is Open
2. Running Query: SELECT * FROM Employee3
Connection must be valid and open.: InvalidOperationException
at MySql.Data.MySqlClient.MySqlCommand.Throw(Exception ex)
at MySql.Data.MySqlClient.MySqlCommand.CheckState()
at MySql.Data.MySqlClient.MySqlCommand.ExecuteReader(CommandBehavior behavior)
at LambdaDBTest.Function.returnRows(MySqlConnection connection)
at LambdaDBTest.Function.FunctionHandler(Stream input, ILambdaContext context)
at lambda_method(Closure , Stream , Stream , ContextInfo)
END RequestId: XXXXXXXXXXXXXXXXXXXXXXXX
REPORT RequestId: XXXXXXXXXXXXXXXXXXXXXXXX Duration: 1203.12 ms Billed Duration: 1300 ms Memory Size: 128 MB Max Memory Used: 47 MB
下面是我使用的代码：
using System;
using System.IO;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using MySql.Data.MySqlClient;
using Amazon.Lambda.Core;
using Amazon.Lambda.Serialization;
using System.Text;
// Assembly attribute to enable the Lambda function's JSON input to be converted into a .NET class.
[assembly: LambdaSerializerAttribute(typeof(Amazon.Lambda.Serialization.Json.JsonSerializer))]
namespace LambdaDBTest
{
public class Function
{
/// <summary>
/// A simple function that takes a string and does a ToUpper
/// </summary>
/// <param name="input"></param>
/// <param name="context"></param>
/// <returns></returns>
public Stream FunctionHandler(Stream input, ILambdaContext context)
{
var dbCon = DBConnection.Instance();
dbCon.Server = "AWS-URI";
dbCon.DatabaseName = "DBNAME";
dbCon.User = "DBUSER";
dbCon.Password = "DBPASS";
string textInput;
if (dbCon.IsConnect())
{
textInput = "Connecion to Database is Open";
LambdaLogger.Log("\n 1. " + textInput);
textInput += returnRows(dbCon.Connection);
}
else
{
textInput = "\n Connecion to Database is NOT Open";
}
dbCon.Close();
LambdaLogger.Log("\n 7. Configure encoding and string to stream\n");
input = new System.IO.MemoryStream(System.Text.Encoding.UTF8.GetBytes(textInput));
return input;
}
public static MemoryStream GenerateStreamFromString(string value)
{
return new MemoryStream(Encoding.UTF8.GetBytes(value ?? ""));
}
static string returnRows(MySqlConnection connection)
{
string output = null;
string query = @"SELECT * FROM Employee3";
LambdaLogger.Log("\n 2. Running Query: " + query);
var cmd = new MySqlCommand(query, connection);
var reader = cmd.ExecuteReader();
LambdaLogger.Log("\n 3. Returning Results");
while (reader.Read())
{
output += "\n" + (string)reader["Name"];
}
LambdaLogger.Log("\n 4. Close connection");
connection.Close();
LambdaLogger.Log("\n 5. Close reader");
reader.Close();
LambdaLogger.Log("\n 6. Dispose cmd");
cmd.Dispose();
return output + "\r";
}
}
}
因此，代码是非常基本的，并使用MySql.Data 6.10.1-β的Nu-获取软件包MySQL和有点剪切和粘贴工作AWS Lambda。
我不明白为什么我在第一次尝试而不是第二次执行时遇到问题。根据我的理解，Lambda的状态保存为零。
希望我做了一些愚蠢或缺少明显的东西，我很乐意收到通知。如果您需要更多信息，请告诉我。
编辑的代码：
所以修复被发现，如下图所示：
public Stream FunctionHandler(Stream input, ILambdaContext context)
{
var dbCon = DBConnection.Instance();
dbCon.Server = "######.rds.amazonaws.com";
dbCon.DatabaseName = "#####";
dbCon.User = "#####";
dbCon.Password = "######";
string textInput;
if (dbCon.IsConnect())
{
textInput = "Connecion to Database is Open";
LambdaLogger.Log("\n 1. " + textInput);
textInput += returnRows(dbCon.Connection);
}
else
{
textInput = "\n Connecion to Database is NOT Open";
}
// LambdaLogger.Log("\n 7. Close Database connection");
//dbCon.Close();
LambdaLogger.Log("\n 8. Configure encoding and string to stream\n");
input = new System.IO.MemoryStream(System.Text.Encoding.UTF8.GetBytes(textInput));
return input;
}
public static MemoryStream GenerateStreamFromString(string value)
{
return new MemoryStream(Encoding.UTF8.GetBytes(value ?? ""));
}
static string returnRows(MySqlConnection connection)
{
string output = null;
string query = @"SELECT * FROM Employee3";
LambdaLogger.Log("\n 2. Running Query: " + query);
var cmd = new MySqlCommand(query, connection);
var reader = cmd.ExecuteReader();
LambdaLogger.Log("\n 3. Returning Results");
while (reader.Read())
{
output += "\n" + (string)reader["Name"];
}
// LambdaLogger.Log("\n 4. Close connection");
//connection.Close();
LambdaLogger.Log("\n 5. Close reader");
reader.Close();
// LambdaLogger.Log("\n 6. Dispose cmd");
//cmd.Dispose();
return output + "\r";
}
过程reader被LAMBDA冻结，所以虽然我没有必要需要关闭MySQL连接因连接到.net MySQL驱动程序的连接池，我确实需要调用reader.Close();来终止冻结的进程。谢谢你Udo举行:)
现在可能要更改您的用户名和密码 – BurnsBA