Using grunt to read a config/database.yml, I've added connection pool options.

var conn = grunt.file.readYAML('config/database.yml')[process.env.NODE_ENV];

defaults: &defaults
host: localhost
username: mark
password: whatever
idle: 30000
reap: 1000

development:
<<: *defaults
database: whatever_development
min: 10
max: 50

production:
host: production.host

database: whatever_production

In lib/pool.js the changes are just ......

pool = genericPool.Pool({
name: name,
min: clientConfig.min || defaults.poolSize,
max: clientConfig.max || defaults.poolSize,
idleTimeoutMillis: clientConfig.idle || defaults.poolIdleTimeout,

reapIntervalMillis: clientConfig.reap || defaults.reapIntervalMillis,

Fancy adding that?