Run Phinx migrations parallel on multiple database exhaust the CPU

[Mubasher-iqbal]

• While running phinx migration on multiple databases always exhaust the database CPU

Use Case
1 database has 17 migrations to execute and there are total of 500 database, I am running 20 in PARALLEL but it always throw below error after executing few.
PDOException: SQLSTATE[HY000] [2002] Connection refused in /composer/vendor/robmorgan/phinx/src/Phinx/Db/Adapter/PdoAdapter.php:83 Stack trace: #0 /composer/vendor/robmorgan/phinx/src/Phinx/Db/Adapter/PdoAdapter.php(83): PDO->__construct('mysql:host=127....', 'dbuser', 'dbpassword', Array)