Change the thread connection

rubyonrails-core
1

How can I change the connection of one thread? I want do that:

slow query process at background

Thread.new do 100000.times { User.first.update_attributes(some_field: (rand * 100).to_i) } end

more slow query process

100000.times { User.first.update_attributes(some_field_2: (rand * 100).to_i) }

``

I want that these 2 threads runs asynchronously but I discover that Rails uses one single connection to do this. I had tried the below too, but although Rails create a new connection, the “User” don’t use it:

slow query process at background

Thread.new do conn = ActiveRecord::Base.connection_pool.checkout() 100000.times { User.first.update_attributes(some_field: (rand * 100).to_i) } ActiveRecord::Base.connection_pool.checkin(conn) end

``

I had tried to set “ActiveRecord::Base.connection = conn” but didn’t work too.

It is possible to each thread have your own connection? How can I set the thread connection?

2

Ok, I got it. But I had to make a little hack on “retrieve_connection” to achieve this:

module ActiveRecord module ConnectionAdapters class ConnectionHandler def retrieve_connection(klass) #:nodoc: pool = retrieve_connection_pool(klass) raise ConnectionNotEstablished, “No connection pool for #{klass}” unless pool conn = Thread.current[“connection”] || pool.connection raise ConnectionNotEstablished, “No connection for #{klass} in connection pool” unless conn conn end end end end

``

I just modify the “conn = pool.connection” to “conn = Thread.current[“connection”] || pool.connection”. This allows me to define the connection using a custom thread variable. With this hack, my code looked like this:

slow query process at background

Thread.new do Thread.current[“connection”] = ActiveRecord::Base.connection_pool.checkout() 100000.times { User.first.update_attributes(some_field: (rand * 100).to_i) } ActiveRecord::Base.connection_pool.checkin(Thread.current[“connection”]) end

more slow query process

100000.times { User.first.update_attributes(some_field_2: (rand * 100).to_i) }

``

This meets my needs, but I wonder if there isn’t a native method to change the connection of a thread. The way I’ve done was so ugly :confused: