Threads and Accessing MySQL

rubyonrails-talk
1

Hi,

I have a function which when called triggers a thread. The function returns after starting the thread.

Thread should access database update few tables and then should end. But I am getting an error when Thread tries to access the database:

Mysql::Error: Lost connection to MySQL server during query: BEGINe[0m

Do i have to open up a new database connection for threads? If so how do I do it?

Any suggestions?

Regards, Sandeep G

2

And if i don't invoke this thread, whole app works fine. So MYSQL connection is intact in main thread, but on spawned thread hits the block with: Mysql::Error: Lost connection to MySQL server during query: BEGINe[0m

Sandeep Gudibanda wrote:

3

And if i don't invoke this thread, whole app works fine. So MYSQL connection is intact in main thread, but on spawned thread hits the block with: Mysql::Error: Lost connection to MySQL server during query: BEGIN [0m

Have you set ActiveRecord::Base.allow_concurency to true ?

Fred

4

AFAIK this is a problem with the mysql connector supplied with Rails. Install mysql gem and then use it in the thread to connect to mysql. MySQL new connections are very light weight and hence there should be no problem with opening extra connection(I may be wrong here)

5

Frederick Cheung wrote:

And if i don't invoke this thread, whole app works fine. So MYSQL connection is intact in main thread, but on spawned thread hits the block with: Mysql::Error: Lost connection to MySQL server during query: BEGIN [0m

Have you set ActiveRecord::Base.allow_concurency to true ?

Fred

If I set this in environment.rb, app fails totally :frowning: Below is the error. #<NoMethodError: undefined method `requires_reloading?' for {}:Hash>

I tried doing , ActiveRecord::Base.establish_connection with in thread. Though it doesn't fail when i do so, i dont see any actions being performed on database though.

I am totally lost! How do I set this allow_concurrency? My develoment machine is windows and I am using webrick.

6

Piyush Ranjan wrote:

AFAIK this is a problem with the mysql connector supplied with Rails. Install mysql gem and then use it in the thread to connect to mysql. MySQL new connections are very light weight and hence there should be no problem with opening extra connection(I may be wrong here)

On Thu, Mar 27, 2008 at 12:41 AM, Frederick Cheung <

Hi Piyush,

I installed mysql-gem (win32) . Do I need to do some intialization in the thread before accessing the database?

Regards, Sandeep G

7

yes you need to do establish_connection

8

Is there an easy way to tell if your app is using the mysql connected supplied with rails? or the compiled version?

Piyush Ranjan wrote: