fix: remove pool-nuking reconnect_db() from OperationalError retry paths

On OperationalError, sql_update and run_sql_select were calling
sql_connect() → reconnect_db() which disposes the entire connection
pool mid-flight, killing other in-flight connections under concurrency.

Removed the sql_connect() calls; the existing retry blocks already open
a fresh engine.connect() context manager, and pool_pre_ping=True handles
stale connection detection. Also drops the now-unused sql_connect import.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
This commit is contained in:
Scott Idem
2026-04-17 17:24:47 -04:00
parent 8f1fe5d4df
commit c7444a8a89
2 changed files with 3 additions and 5 deletions

View File

@@ -15,8 +15,8 @@
## 🔌 DB Connection Hardening (April 2026 Audit)
> Identified during pre-show review. Issues 1 and 2 likely explain observed random connection lags.
- [ ] **[P1] Remove zombie `db_connection.py` import** — `app/routers/api.py` imports `db` from `app/db_connection.py`, creating a parasitic second SQLAlchemy engine at startup that is never updated by `reconnect_db()` after bootstrap. The imported `db` is only used in a commented-out line (`api.py:268`). Fix: remove the import; delete or archive `db_connection.py`.
- [ ] **[P1] Fix retry mechanism in `sql_update` / `run_sql_select`** — On `OperationalError`, both call `sql_connect()``reconnect_db()` which calls `engine.dispose()`, nuking the entire connection pool mid-flight. Under concurrent requests this kills other in-flight connections. Fix: remove the `sql_connect()` retry call; SQLAlchemy's `pool_pre_ping=True` already handles stale connections — just open a fresh `engine.connect()` for the retry without disposing the pool.
- [x] **[P1] Remove zombie `db_connection.py` import** — `app/routers/api.py` imports `db` from `app/db_connection.py`, creating a parasitic second SQLAlchemy engine at startup that is never updated by `reconnect_db()` after bootstrap. The imported `db` is only used in a commented-out line (`api.py:268`). Fix: remove the import; delete or archive `db_connection.py`.
- [x] **[P1] Fix retry mechanism in `sql_update` / `run_sql_select`** — On `OperationalError`, both call `sql_connect()``reconnect_db()` which calls `engine.dispose()`, nuking the entire connection pool mid-flight. Under concurrent requests this kills other in-flight connections. Fix: remove the `sql_connect()` retry call; SQLAlchemy's `pool_pre_ping=True` already handles stale connections — just open a fresh `engine.connect()` for the retry without disposing the pool.
- [ ] **[P2] Add retry logic to `sql_insert` and `sql_select`** — Both are missing the `OperationalError` retry that `sql_update` and `run_sql_select` have. A DB blip during an INSERT (scan record, badge log, etc.) fails silently and returns `False` with no recovery attempt.
- [ ] **[P3] Guard `db = engine.connect()` in `lib_sql_core.py` with try/except** — Line 48 is a bare connect at module load time with no error handling. If MariaDB isn't ready (Docker race), this throws unhandled and crashes the worker. Wrap in try/except like `db_connection.py` already does.
- [ ] **[P4] Expose `pool_size` / `max_overflow` as env vars** — `create_ae_engine()` calls `settings.DB.get('pool_size', 10)` but `settings.DB` property doesn't include those keys, so they're always hardcoded 10/20. Add `AE_DB_POOL_SIZE` / `AE_DB_POOL_MAX_OVERFLOW` to `config.py`.