Configure DB Connection Poolling

[btylerburton]

User Story

In order to avoid running into a connection error with our Postgres DB, datagovteam wants to configure the connection from flask -> db correctly.

Acceptance Criteria

[ACs should be clearly demoable/verifiable whenever possible. Try specifying them using BDD.]

• GIVEN I have enabled a Gunicorn WSGI server
  THEN I want to determine the appropriate Gunicorn config
  AND optional thread pooling libraries to create a stable connection to the Postgres backend via SqlAlchemy

Background

Slack thread on connection overload: https://gsa-tts.slack.com/archives/C09CR1Q9Z/p1730929937757879

Background:

• https://stackoverflow.com/questions/12650048/how-can-i-pool-connections-using-psycopg-and-gevent
• https://github.com/zacharyvoase/gevent-psycopg2?tab=readme-ov-file
• https://github.com/gevent/gevent/blob/master/examples/psycopg2_pool.py
• https://www.psycopg.org/docs/pool.html
• https://repost.aws/knowledge-center/troubleshoot-rds-swap-memory
• https://stackoverflow.com/questions/45113145/the-right-way-to-use-gevent-with-sqlalchemy

Security Considerations (required)

[Any security concerns that might be implicated in the change. "None" is OK, just be explicit here!]

Sketch

• Determine best fit worker-class configuration (gevent or gthread) for Gunicorn WSGI server
• Determine if psychopg is needed to create a connection pool
• Determine if psycogreen will help with gevent connection pooling