英文:
Lost connection to MySQL server during aggregate UDF execution
问题
我在C++中创建了一个MySQL UDF，并将其上传到MySQL的插件目录中。我能够在MySQL中安装这个UDF，但当我尝试调用它时，MySQL服务器会停止。我在Windows 10操作系统上使用Visual Studio 2019来创建共享库（在Windows上是.dll文件）。
我在我的MySQL C++ UDF中从Java中调用了一个方法，我使用GraalVM从C++函数调用Java方法。
我将我的Java代码制作成了一个共享库，并在我的C++代码中使用它们来访问我的Java方法。
MySQL UDF 代码：DemoAgg.cpp
#ifdef STANDARD
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#ifdef __WIN__
typedef unsigned __int64 ulonglong;
typedef __int64 longlong;
#else
typedef unsigned long long ulonglong;
typedef long long longlong;
#endif /*__WIN__*/
#endif
#include <mysql.h>
#include <iostream>
#include <ctype.h>
#include <demolibmysqlagg.h>
extern "C" bool test_agg_init(UDF_INIT * initid, UDF_ARGS * args, char* message)
{
long long* i = new long long;
*i = 0;
initid->ptr = (char*)i;
std::cout << "in init func" << std::endl;
if (args->arg_count != 1)
{
strcpy_s(message, 50, "testagg() requires one arguments");
return 1;
}
if (args->arg_type[0] != INT_RESULT)
{
strcpy_s(message, 50, "testagg() requires one integer");
return 1;
}
return 0;
}
extern "C" void test_agg_deinit(UDF_INIT * initid)
{
std::cout << "in deinit func" << std::endl;
delete (long long*)initid->ptr;
}
extern "C" void test_agg_clear(UDF_INIT* initid, char* is_null, char* error)
{
std::cout << "in clear func" << std::endl;
*((long long*)initid->ptr) = 0;
}
extern "C" void test_agg_add(UDF_INIT* initid, UDF_ARGS* args, char* is_null, char* error)
{
graal_isolate_t* isolate = NULL;
graal_isolatethread_t* thread = NULL;
std::cout << "in add func" << std::endl;
long long int_val;
int_val = *((long long*)initid->ptr);
long long int_val2;
int_val2 = *((long long*)args->args[0]);
long long sum;
sum = aggadd(thread, int_val, int_val2); //my java method which i call from this program
std::cout << sum;
*((long long*)initid->ptr) = sum;
}
extern "C" long long test_agg(UDF_INIT* initid, UDF_ARGS* args, char* is_null, char* error)
{
std::cout << "in main func" << std::endl;
return *((long long*)initid->ptr);
}
我的模块定义文件：DemoAgg.def
LIBRARY testagg
EXPORTS
test_agg_init
test_agg_deinit
test_agg_clear
test_agg_add
test_agg
我的Java代码：
package testmysql;
import org.graalvm.nativeimage.IsolateThread;
import org.graalvm.nativeimage.c.function.CEntryPoint;
public class demo_mysqlagg {
@CEntryPoint (name = "aggadd")
public static int aggadd(IsolateThread thread, int x, int y) {
return x + y;
}
}
在构建完我的C++项目后，我得到一个dll文件，然后将其复制到MySQL的插件目录中。
我使用以下查询来安装UDF：
create aggregate function test_agg returns integer soname 'testagg.dll';
我使用以下查询来调用我的UDF：
select test_agg(c1) from demo_agg;
其中，
demo_agg是只有一列的表。c1是整数类型的列名。
但是，当我执行上述查询时，会出现以下错误：
18:52:53 select test_agg(c1) from demo_agg LIMIT 0, 1000 Error Code: 2013. Lost connection to MySQL server during query 0.063 sec
我的错误日志：
2020-09-29T14:41:24.584058Z 0 [Warning] [MY-010915] [Server] 'NO_ZERO_DATE', 'NO_ZERO_IN_DATE' and 'ERROR_FOR_DIVISION_BY_ZERO' sql modes should be used with strict mode. They will be merged with strict mode in a future release.
...
...
(in init func)
(in clear func)
(in add func)
...
...
我添加了一些cout语句以了解我在哪个函数中。
请问有谁能帮我解决这个问题吗？我在这里做错了什么？任何形式的帮助或建议都将非常有帮助。
英文:
I created a MySQL UDF in C++ and uploaded it into the MySQL's plugin directory.
I am able to install the UDF in MySQL, but when I try to call it, the MySQL server stops.
I am using visual studio 2019 to create the shared library(.dll in windows) on windows 10 operating system.
I am calling a method from java in my MySQL C++ UDF, I am using graalVM to call the java methods from C++ functions.
I created a shared library out of my java code and I use them in my C++ code to access my java methods.
MySQL UDF code:DemoAgg.cpp
#ifdef STANDARD
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#ifdef __WIN__
typedef unsigned __int64 ulonglong;
typedef __int64 longlong;
#else
typedef unsigned long long ulonglong;
typedef long long longlong;
#endif /*__WIN__*/
#endif
#include <mysql.h>
#include <iostream>
#include <ctype.h>
#include <demolibmysqlagg.h>
extern "C" bool test_agg_init(UDF_INIT * initid, UDF_ARGS * args, char* message)
{
long long* i = new long long;
*i = 0;
initid->ptr = (char*)i;
std::cout << "in init func" << std::endl;
if (args->arg_count != 1)
{
strcpy_s(message, 50, "testagg() requires one arguments");
return 1;
}
if (args->arg_type[0] != INT_RESULT)
{
strcpy_s(message, 50, "testagg() requires one integer");
return 1;
}
return 0;
}
extern "C" void test_agg_deinit(UDF_INIT * initid)
{
std::cout << "in deinit func" << std::endl;
delete (long long*)initid->ptr;
}
extern "C" void test_agg_clear(UDF_INIT* initid, char* is_null, char* error)
{
std::cout << "in clear func" << std::endl;
*((long long*)initid->ptr) = 0;
}
extern "C" void test_agg_add(UDF_INIT* initid, UDF_ARGS* args, char* is_null, char* error)
{
graal_isolate_t* isolate = NULL;
graal_isolatethread_t* thread = NULL;
std::cout << "in add func" << std::endl;
long long int_val;
int_val = *((long long*)initid->ptr);
long long int_val2;
int_val2 = *((long long*)args->args[0]);
long long sum;
sum = aggadd(thread, int_val, int_val2); //my java method which i call from this program
std::cout << sum;
*((long long*)initid->ptr) = sum;
}
extern "C" long long test_agg(UDF_INIT* initid, UDF_ARGS* args, char* is_null, char* error)
{
std::cout <<"in main func"<<std::endl;
return *((long long*)initid->ptr);
}
My Module Definition File:DemoAgg.def
LIBRARY testagg
EXPORTS
test_agg_init
test_agg_deinit
test_agg_clear
test_agg_add
test_agg
My java code:
package testmysql;
import org.graalvm.nativeimage.IsolateThread;
import org.graalvm.nativeimage.c.function.CEntryPoint;
public class demo_mysqlagg {
@CEntryPoint (name = "aggadd")
public static int aggadd(IsolateThread thread, int x, int y) {
return x+y;
}
}
After building my C++ project, I get a dll file which I copy to the MySQL's plugin directory.
I install the UDF using the following query:
create aggregate function test_agg returns integer soname 'testagg.dll';
I call my UDF using the following query:
select test_agg(c1) from demo_agg;
where,
> demo_agg is a table with only one column.
> c1 is the column name of type integer.
But when I execute the above query, the following error pops up:
18:52:53 select test_agg(c1) from demo_agg LIMIT 0, 1000 Error Code: 2013. Lost connection to MySQL server during query 0.063 sec
My error log:
2020-09-29T14:41:24.584058Z 0 [Warning] [MY-010915] [Server] 'NO_ZERO_DATE', 'NO_ZERO_IN_DATE' and 'ERROR_FOR_DIVISION_BY_ZERO' sql modes should be used with strict mode. They will be merged with strict mode in a future release.
2020-09-29T14:41:24.587014Z 0 [System] [MY-010116] [Server] C:\Program Files\MySQL\MySQL Server 8.0\bin\mysqld.exe (mysqld 8.0.21) starting as process 48276
2020-09-29T14:41:24.653757Z 1 [System] [MY-013576] [InnoDB] InnoDB initialization has started.
2020-09-29T14:41:28.123852Z 1 [System] [MY-013577] [InnoDB] InnoDB initialization has ended.
2020-09-29T14:41:28.958692Z 0 [System] [MY-011323] [Server] X Plugin ready for connections. Bind-address: '::' port: 33060
2020-09-29T14:41:30.249252Z 0 [Warning] [MY-010068] [Server] CA certificate ca.pem is self signed.
2020-09-29T14:41:30.250713Z 0 [System] [MY-013602] [Server] Channel mysql_main configured to support TLS. Encrypted connections are now supported for this channel.
2020-09-29T14:41:30.653518Z 0 [System] [MY-010931] [Server] C:\Program Files\MySQL\MySQL Server 8.0\bin\mysqld.exe: ready for connections. Version: '8.0.21' socket: '' port: 3306 MySQL Community Server - GPL.
in init func
in clear func
in add func
2020-09-29T14:42:49.045501Z 0 [Warning] [MY-010915] [Server] 'NO_ZERO_DATE', 'NO_ZERO_IN_DATE' and 'ERROR_FOR_DIVISION_BY_ZERO' sql modes should be used with strict mode. They will be merged with strict mode in a future release.
2020-09-29T14:42:49.053090Z 0 [System] [MY-010116] [Server] C:\Program Files\MySQL\MySQL Server 8.0\bin\mysqld.exe (mysqld 8.0.21) starting as process 188880
2020-09-29T14:42:49.102031Z 1 [System] [MY-013576] [InnoDB] InnoDB initialization has started.
2020-09-29T14:42:53.150956Z 1 [System] [MY-013577] [InnoDB] InnoDB initialization has ended.
2020-09-29T14:42:53.914379Z 0 [System] [MY-011323] [Server] X Plugin ready for connections. Bind-address: '::' port: 33060
2020-09-29T14:42:54.728381Z 0 [System] [MY-010229] [Server] Starting XA crash recovery...
2020-09-29T14:42:54.737801Z 0 [System] [MY-010232] [Server] XA crash recovery finished.
2020-09-29T14:42:55.464369Z 0 [Warning] [MY-010068] [Server] CA certificate ca.pem is self signed.
2020-09-29T14:42:55.465965Z 0 [System] [MY-013602] [Server] Channel mysql_main configured to support TLS. Encrypted connections are now supported for this channel.
2020-09-29T14:42:56.133327Z 0 [System] [MY-010931] [Server] C:\Program Files\MySQL\MySQL Server 8.0\bin\mysqld.exe: ready for connections. Version: '8.0.21' socket: '' port: 3306 MySQL Community Server - GPL.
I put some cout statements to know in which function I am.
Can anyone help me out here?
What I am doing here?
Any kind of help or suggestion will be of great help.
答案1
得分: 0
问题出在：
graal_isolate_t* isolate = NULL;
graal_isolatethread_t* thread = NULL;
它们是空的，所以无法调用 Java 方法，连接超时。
如果我像这样初始化它们：
if (graal_create_isolate(NULL, &isolate, &thread) != 0) {
fprintf(stderr, "initialization error\n");
return;
}
那么它就能正常工作。
英文:
the problem is with:
graal_isolate_t* isolate = NULL;
graal_isolatethread_t* thread = NULL;
they are null, that's why it is not able to call the java method and the connection is getting timed out.
if I initialize them like this:
if (graal_create_isolate(NULL, &isolate, &thread) != 0) {
fprintf(stderr, "initialization error\n");
return;
}
then it is working fine.
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