Fix PostgreSQL connection exhaustion (too many clients) with gevent workers

.envs/.production/.django

@@ -52,21 +52,17 @@ FETCH_DATA_TIMEOUT=10
 # Exemplo: 10 segundos
 DB_CONNECT_TIMEOUT=10
 
-# --- Opções de Pool de Conexões ---
-# (Aplicável se você estiver usando uma biblioteca de pool de conexões integrada ao Django,
-# como django-db-connection-pool, que reconheça POOL_OPTIONS.)
+# --- Gunicorn ---
+# Number of gunicorn worker processes
+# GUNICORN_WORKERS=3
 
-# Tamanho mínimo do pool de conexões
-# Exemplo: 10 conexões
-DB_POOL_SIZE=10
+# Max simultaneous connections per worker (gevent greenlets)
+# GUNICORN_WORKER_CONNECTIONS=1000
 
-# Número máximo de conexões extras que o pool pode criar em caso de pico
-# Exemplo: 20 conexões de "overflow"
-DB_MAX_OVERFLOW=20
-
-# Tempo máximo (em segundos) que uma conexão pode viver antes de ser reciclada
-# Ajuda a evitar conexões "stale" ou "bad". Exemplo: 300 segundos (5 minutos)
-DB_RECYCLE=300
+# Django CONN_MAX_AGE: seconds to keep DB connections alive (0 = close after each request).
+# Use 0 (default) with gevent to prevent connection exhaustion
+# (each greenlet holds its own connection when CONN_MAX_AGE > 0).
+# CONN_MAX_AGE=0
 
 
 # ---- profiling 

compose/production/django/start

@@ -26,4 +26,16 @@ if compress_enabled; then
   # NOTE this command will fail if django-compressor is disabled
   python /app/manage.py compress
 fi
-/usr/local/bin/gunicorn config.wsgi --bind 0.0.0.0:5000 --chdir=/app --timeout 1000 --workers 3 --worker-connections=1000 --worker-class=gevent
+
+GUNICORN_WORKERS=${GUNICORN_WORKERS:-3}
+GUNICORN_WORKER_CONNECTIONS=${GUNICORN_WORKER_CONNECTIONS:-1000}
+GUNICORN_WORKER_CLASS=${GUNICORN_WORKER_CLASS:-gevent}
+GUNICORN_TIMEOUT=${GUNICORN_TIMEOUT:-1000}
+
+/usr/local/bin/gunicorn config.wsgi \
+    --bind 0.0.0.0:5000 \
+    --chdir=/app \
+    --timeout "$GUNICORN_TIMEOUT" \
+    --workers "$GUNICORN_WORKERS" \
+    --worker-connections="$GUNICORN_WORKER_CONNECTIONS" \
+    --worker-class="$GUNICORN_WORKER_CLASS"

config/settings/production.py

@@ -14,19 +14,16 @@
 # ------------------------------------------------------------------------------
 DATABASES["default"] = env.db("DATABASE_URL")  # noqa F405
 DATABASES["default"]["ATOMIC_REQUESTS"] = True  # noqa F405
-DATABASES["default"]["CONN_MAX_AGE"] = env.int("CONN_MAX_AGE", default=0) or env.int("DJANGO_CONN_MAX_AGE", default=60)  # noqa F405
+# CONN_MAX_AGE=0 closes DB connections after each request, which is recommended
+# when using gevent workers to prevent connection exhaustion — each greenlet
+# holds its own persistent connection when CONN_MAX_AGE > 0.
+# Set CONN_MAX_AGE env var to a positive integer (e.g. 60) only if using a
+# connection pooler like PgBouncer in front of PostgreSQL.
+DATABASES["default"]["CONN_MAX_AGE"] = env.int("CONN_MAX_AGE", default=0)  # noqa F405
 DATABASES["default"]["CONN_HEALTH_CHECKS"] = env.bool('DJANGO_CONN_HEALTH_CHECKS', True)
 DATABASES["default"]["ENGINE"] = 'django_prometheus.db.backends.postgresql'
-# Melhoria: Usando variáveis de ambiente para OPTIONS e POOL_OPTIONS com defaults
 DATABASES["default"]["OPTIONS"] = {
     "connect_timeout": env.int("DB_CONNECT_TIMEOUT", default=10),
-    # Adicione outras opções de conexão aqui se necessário
-}
-DATABASES["default"]["POOL_OPTIONS"] = {
-    'POOL_SIZE': env.int("DB_POOL_SIZE", default=10),
-    'MAX_OVERFLOW': env.int("DB_MAX_OVERFLOW", default=20),
-    'RECYCLE': env.int("DB_RECYCLE", default=300),
-    # Adicione outras opções do pool aqui se necessário
 }
 # CACHES
 # ------------------------------------------------------------------------------