Parallel_tests database does not exist

Question

I am using parallel_tests gem for running my rails 6 app tests in CI. In logs, I see all 9 databases with ENV[TEST_ENV_NUMBER] are being created, and then it just fails saying that these databases do not exist.

The commands I run are:

bin/bundle install
bin/bundle exec rake parallel:setup
bin/bundle exec rake parallel:spec

Logs are the following:

Created database 'my_db_name4'
 set_config 
------------
 
(1 row)
Created database 'my_db_name'
 set_config 
------------
 
(1 row)
Created database 'my_db_name2'
 set_config 
------------
 
(1 row)
Created database 'my_db_name5'
 set_config 
------------
 
(1 row)
Created database 'my_db_name7'
 set_config 
------------
 
(1 row)
Created database 'my_db_name8'
 set_config 
------------
 
(1 row)
Created database 'my_db_name6'
 set_config 
------------
 
(1 row)
Created database 'my_db_name3'
 set_config 
------------
 
(1 row)

bin/bundle exec rake parallel:spec

rake aborted!
ActiveRecord::NoDatabaseError: FATAL:  database "my_db_name1" does not exist
/usr/local/bundle/gems/activerecord-6.0.3/lib/active_record/connection_adapters/postgresql_adapter.rb:50:in `rescue in postgresql_connection'
/usr/local/bundle/gems/activerecord-6.0.3/lib/active_record/connection_adapters/postgresql_adapter.rb:33:in `postgresql_connection'
/usr/local/bundle/gems/activerecord-6.0.3/lib/active_record/connection_adapters/abstract/connection_pool.rb:887:in `new_connection'
/usr/local/bundle/gems/activerecord-6.0.3/lib/active_record/connection_adapters/abstract/connection_pool.rb:931:in `checkout_new_connection'
/usr/local/bundle/gems/activerecord-6.0.3/lib/active_record/connection_adapters/abstract/connection_pool.rb:910:in `try_to_checkout_new_connection'
/usr/local/bundle/gems/activerecord-6.0.3/lib/active_record/connection_adapters/abstract/connection_pool.rb:871:in `acquire_connection'
/usr/local/bundle/gems/activerecord-6.0.3/lib/active_record/connection_adapters/abstract/connection_pool.rb:593:in `checkout'
/usr/local/bundle/gems/activerecord-6.0.3/lib/active_record/connection_adapters/abstract/connection_pool.rb:437:in `connection'
/usr/local/bundle/gems/activerecord-6.0.3/lib/active_record/connection_adapters/abstract/connection_pool.rb:1119:in `retrieve_connection'
/usr/local/bundle/gems/activerecord-6.0.3/lib/active_record/connection_handling.rb:221:in `retrieve_connection'
/usr/local/bundle/gems/activerecord-6.0.3/lib/active_record/connection_handling.rb:189:in `connection'
/usr/local/bundle/gems/activerecord-6.0.3/lib/active_record/railties/databases.rake:261:in `block (3 levels) in <main>'
/usr/local/bundle/gems/activerecord-6.0.3/lib/active_record/railties/databases.rake:258:in `each'
/usr/local/bundle/gems/activerecord-6.0.3/lib/active_record/railties/databases.rake:258:in `flat_map'
/usr/local/bundle/gems/activerecord-6.0.3/lib/active_record/railties/databases.rake:258:in `block (2 levels) in <main>'
/usr/local/bundle/gems/parallel_tests-3.0.0/lib/parallel_tests/tasks.rb:71:in `block in check_for_pending_migrations'
/usr/local/bundle/gems/parallel_tests-3.0.0/lib/parallel_tests/tasks.rb:69:in `each'
/usr/local/bundle/gems/parallel_tests-3.0.0/lib/parallel_tests/tasks.rb:69:in `check_for_pending_migrations'
/usr/local/bundle/gems/parallel_tests-3.0.0/lib/parallel_tests/tasks.rb:183:in `block (3 levels) in <main>'
bin/bundle:113:in `load'
bin/bundle:113:in `<main>'
Caused by:
PG::ConnectionBad: FATAL:  database "my_db_name1" does not exist
/usr/local/bundle/gems/pg-1.2.3/lib/pg.rb:58:in `initialize'
/usr/local/bundle/gems/pg-1.2.3/lib/pg.rb:58:in `new'
/usr/local/bundle/gems/pg-1.2.3/lib/pg.rb:58:in `connect'
/usr/local/bundle/gems/activerecord-6.0.3/lib/active_record/connection_adapters/postgresql_adapter.rb:46:in `postgresql_connection'
/usr/local/bundle/gems/activerecord-6.0.3/lib/active_record/connection_adapters/abstract/connection_pool.rb:887:in `new_connection'
/usr/local/bundle/gems/activerecord-6.0.3/lib/active_record/connection_adapters/abstract/connection_pool.rb:931:in `checkout_new_connection'
/usr/local/bundle/gems/activerecord-6.0.3/lib/active_record/connection_adapters/abstract/connection_pool.rb:910:in `try_to_checkout_new_connection'
/usr/local/bundle/gems/activerecord-6.0.3/lib/active_record/connection_adapters/abstract/connection_pool.rb:871:in `acquire_connection'
/usr/local/bundle/gems/activerecord-6.0.3/lib/active_record/connection_adapters/abstract/connection_pool.rb:593:in `checkout'
/usr/local/bundle/gems/activerecord-6.0.3/lib/active_record/connection_adapters/abstract/connection_pool.rb:437:in `connection'
/usr/local/bundle/gems/activerecord-6.0.3/lib/active_record/connection_adapters/abstract/connection_pool.rb:1119:in `retrieve_connection'
/usr/local/bundle/gems/activerecord-6.0.3/lib/active_record/connection_handling.rb:221:in `retrieve_connection'
/usr/local/bundle/gems/activerecord-6.0.3/lib/active_record/connection_handling.rb:189:in `connection'
/usr/local/bundle/gems/activerecord-6.0.3/lib/active_record/railties/databases.rake:261:in `block (3 levels) in <main>'
/usr/local/bundle/gems/activerecord-6.0.3/lib/active_record/railties/databases.rake:258:in `each'
/usr/local/bundle/gems/activerecord-6.0.3/lib/active_record/railties/databases.rake:258:in `flat_map'
/usr/local/bundle/gems/activerecord-6.0.3/lib/active_record/railties/databases.rake:258:in `block (2 levels) in <main>'
/usr/local/bundle/gems/parallel_tests-3.0.0/lib/parallel_tests/tasks.rb:71:in `block in check_for_pending_migrations'
/usr/local/bundle/gems/parallel_tests-3.0.0/lib/parallel_tests/tasks.rb:69:in `each'
/usr/local/bundle/gems/parallel_tests-3.0.0/lib/parallel_tests/tasks.rb:69:in `check_for_pending_migrations'
/usr/local/bundle/gems/parallel_tests-3.0.0/lib/parallel_tests/tasks.rb:183:in `block (3 levels) in <main>'
bin/bundle:113:in `load'
bin/bundle:113:in `<main>'
Tasks: TOP => db:abort_if_pending_migrations
(See full trace by running task with --trace)```

Am I doing something wrong? I suspect databases are being destroyed somewhere, but I don't know where to look.

Answer 1

So, that was quite easy, but hard to find =( I found out that I had TEST_ENV_NUMBER env variable set to 1 in CI. So, it tried to connect to the database my_db_name1 from every process, I guess. Once I removed this variable, everything started to work just fine. It's still interesting for me why this database has not been created as pointed by @cdadityang in the comments.