1.19.0 — Bounded PostgreSQL pooling and complete transactional email templates

2026-08-24

django-mojo 1.19.0 uses bounded, health-checked psycopg 3 pools for PostgreSQL under ASGI, completes the built-in transactional account email templates, and treats paid database/cache redundancy as an explicit availability choice.

Breaking

• PostgreSQL deployments now standardize on psycopg 3 with its native pool package. Django ORM users should be transparent, but application code that imports psycopg2 directly or relies on psycopg2-specific raw-driver behavior must migrate or be tested before upgrading.
• Otherwise-unconfigured PostgreSQL aliases now receive a native pool per process with min_size=1, max_size=4, timeout=5, max_idle=300, and max_lifetime=1800; CONN_MAX_AGE remains 0 as required for Django pooling under ASGI. With the default four Uvicorn workers this permits up to 16 connections per node per alias.

Added

• Default templates now cover every built-in transactional account email flow, including invitations, magic login, password reset, email verification, email change, and account deactivation.

Changed

• Derived database-reader aliases receive an independent bounded pool instead of a 60-second persistent connection.
• Transactional link emails now render server-resolved frontend URLs instead of raw tokens or placeholder hosts.
• The reference AWS audit now treats a writer-only Aurora cluster or single-node cache as an explicit cost/recovery choice rather than a deployment failure; misconfigured paid replicas remain visible as warnings.

Fixed

• Missing template seeds and placeholder-host link templates no longer silently leave built-in account flows with unusable email.

Upgrade notes

• Replace the default pool globally with DATABASE_POOL_OPTIONS, or set it to False to disable automatic pooling. An explicit per-alias CONN_MAX_AGE or the legacy DATABASE_CONN_MAX_AGE also opts that alias out.
• Size connection capacity as nodes × Uvicorn workers × sum(alias max_size), leaving headroom for migrations, background processes, operators, and failover.
• RDS Proxy and PgBouncer remain separate infrastructure layers. Transaction-mode poolers require DISABLE_SERVER_SIDE_CURSORS = True; django-mojo's session advisory-lock paths must be isolated or redesigned before using PgBouncer transaction mode. RDS Proxy preserves those paths by pinning their client connections, reducing multiplexing.
• Shipped template loading remains missing-only and will not overwrite customized database rows. Run python manage.py seed_email_templates --update-existing only when you intend to replace existing templates with the shipped versions.