Lost Connection During Query

[vkamadan]

Hi,
I'm working on MyDAC 4.40.0.25 with MySQL 5.0 and MySQL 4.0.18,
My problem is,

Code: Select all

//My system date set is 26.09.2007
myQuery.Open;
//successfully
//My system date set is 27.09.2007
myQuery.Close;
myQuery.Open;
//raise exception Lost Connection During Query

What's wrong?
Solution please.

Best Regards.

[Antaeus]

Please specify the following information:
- do you use the FetchAll=False mode?
- does the problem appear if you run your application out of debugger control?
- does the problem appear when you open the query second time, or when you close the first query?
- does your query contain BLOB fields?
- how much data do your queries return?

[vkamadan]

Please specify the following information:
- do you use the FetchAll=False mode?
- does the problem appear if you run your application out of debugger control?
- does the problem appear when you open the query second time, or when you close the first query?
- does your query contain BLOB fields?
- how much data do your queries return?

Hi,
I'm test project is very simple , my form include just, 1 TMyConnection, 1 TMyQuery , 1 TDataSource and 1 TDbGrid objects, my test table include just 1 row data.

Please try a following step,

1. Application run,
2.Query Open
3.System date set a tomorrow (Application must be is already run)
4.Query Close
5.Query open , Raise Exception


But ,

1. Application run,
2.Query Open
3.System date set a tomorrow (Application must be is already run)
4.MyCOnneciton.Disconnect
5.MyCOnneciton.Connect;
6.Query open , successfuly executed my query

but, it is not a solution for me, this is not enough.

Thank's for feedback ,my best regards.

[vkamadan]

Hi again,

Please view my problem a following video,

http://www.polisoftonline.com/download/ ... roblem.wmv

[Antaeus]

Thank you for such detailed description of the problem.
This is not an issue of MyDAC. This depends on settings of your server, specifically on the interactive_timeout parameter. It is measures in seconds. MySQL closes connections which are inactive more than the interval specified in this parameter.
Try to restart your MySQL setting this parameter to a greater value. The maximum possible value is 31536000, which equals to one year.
You can set value of this parameter in the configuration file of MySQL (my.ini), or in the command line:

Code: Select all

  %MySQL_inst_dir%\mysqld.exe --interactive_timeout=31536000

[vkamadan]

Thank's for urgently feedback,

I'm add follawing parametres in my.ini solve my problem

interactive_timeout = 31536000
wait_timeout = 31536000
net_read_timeout = 31536000
net_write_timeout = 31536000
slave_net_timeout = 31536000

Thank you for your offer a solution.

Foot note;
but at the some time, without new parameters, issueless ODBC based database access.this exception raise is just mydac direct connection metod.


My best regards.

[eduardosic]

Thank's for urgently feedback,

I'm add follawing parametres in my.ini solve my problem

interactive_timeout = 31536000
wait_timeout = 31536000
net_read_timeout = 31536000
net_write_timeout = 31536000
slave_net_timeout = 31536000

Thank you for your offer a solution.

Foot note;
but at the some time, without new parameters, issueless ODBC based database access.this exception raise is just mydac direct connection metod.


My best regards.

my my.ini file for all...

Code: Select all

[client]
port	                             = 3306

[mysqld]

port		                     = 3306
connect_timeout                      = 31536000
interactive_timeout		     = 31536000
wait_timeout                         = 31536000
net_read_timeout                     = 31536000
net_write_timeout                    = 31536000
slave_net_timeout                    = 31536000
max_connections                      = 31536000
max_user_connections                 = 31536000

basedir                              = "F:/mySQL/"
datadir                              = "F:/mySQL/Data/"
language                             = "F:/mySQL/share/portuguese"

default-character-set                = latin1
default-storage-engine               = INNODB
server-id	                     = 1
tmpdir		                     = C:/Temp
max_allowed_packet                   = 16M


#Influencia no uso da memória virtual
key_buffer_size                      = 64M


# INNODB 

innodb_data_file_path                = ibdata1:2000M:autoextend
innodb_data_home_dir                 = "F:/mySQL/InnoDB"
innodb_log_group_home_dir            = "F:/MySQL/InnoDB"
innodb_log_arch_dir                  = "F:/MySQL/InnoDB"


#Influencia no uso da memória virtual
innodb_buffer_pool_size              = 512M


#Influencia no uso da memória virtual
innodb_additional_mem_pool_size      = 16M


#Influencia no uso da memória virtual
innodb_log_buffer_size               = 64M

innodb_log_file_size                 = 64M

innodb_lock_wait_timeout             = 50
innodb_flush_log_at_trx_commit       = 1
innodb_file_io_threads               = 4

[Antaeus]

Such exception may be raised in many other cases.
We introduced support for handling such situations in MyDAC 5 (Local Failover and Disconnected Model features). You can consider upgrading to MyDAC 5 if this is important for you.

[eduardosic]

Such exception may be raised in many other cases.
We introduced support for handling such situations in MyDAC 5 (Local Failover and Disconnected Model features). You can consider upgrading to MyDAC 5 if this is important for you.

Hi, Antaeus is rigth, after the MyDAC 5 never more I had problems, mainly in access it saw unstable Internet and nets.

localfailover, Disconnected Model and Pooling, very very good.

[vkamadan]

@eduardosic ,thank's for support.

My best regards.