diff --git a/guides/source/configuring.md b/guides/source/configuring.md index 5f170474eeadef349c5651f97cb3cc427eb654cc..c499cd0727822812a0b38a235dc7166514ae5df3 100644 --- a/guides/source/configuring.md +++ b/guides/source/configuring.md @@ -759,4 +759,15 @@ Since the connection pooling is handled inside of Active Record by default, all Any one request will check out a connection the first time it requires access to the database, after which it will check the connection back in, at the end of the request, meaning that the additional connection slot will be available again for the next request in the queue. +If you try to use more connections than are available, Active Record will block +and wait for a connection from the pool. When it cannot get connection, a timeout +error similar to given below will be thrown. + +```ruby +ActiveRecord::ConnectionTimeoutError - could not obtain a database connection within 5 seconds. The max pool size is currently 5; consider increasing it: +``` + +If you get the above error, you might want to increase the size of connection +pool by incrementing the `pool` option in `database.yml` + NOTE. If you have enabled `Rails.threadsafe!` mode then there could be a chance that several threads may be accessing multiple connections simultaneously. So depending on your current request load, you could very well have multiple threads contending for a limited amount of connections. diff --git a/railties/lib/rails/generators/rails/app/templates/config/databases/postgresql.yml b/railties/lib/rails/generators/rails/app/templates/config/databases/postgresql.yml index eb569b7dabc3b3140ea5d3895b75e04513119e56..0194dce6f373ab4933ec6284ee7e1072098fe9f2 100644 --- a/railties/lib/rails/generators/rails/app/templates/config/databases/postgresql.yml +++ b/railties/lib/rails/generators/rails/app/templates/config/databases/postgresql.yml @@ -55,6 +55,8 @@ production: adapter: postgresql encoding: unicode database: <%= app_name %>_production + # For details on connection pooling, see rails configration guide + # http://guides.rubyonrails.org/configuring.html#database-pooling pool: 5 username: <%= app_name %> password: