[db] Postgresql setup (#12051)

* Adjust default postgres connection settings

* Support tcp_user_timeout

* Set application name based on running context

* Add CONN_MAX_AGE and CONN_HEALTH_CHECKS

* Add connection timeout option for mysql

docs/docs/start/config.md

@@ -256,6 +256,9 @@ The following database options can be configured:
 {{ configsetting("INVENTREE_DB_PASSWORD") }} Database password (if required) |
 {{ configsetting("INVENTREE_DB_HOST") }} Database host address (if required) |
 {{ configsetting("INVENTREE_DB_PORT") }} Database host port (if required) |
+{{ configsetting("INVENTREE_DB_CONN_MAX_AGE") }} Database connection max age (s) |
+{{ configsetting("INVENTREE_DB_CONN_HEALTH_CHECKS") }} Enable database connection health checks |
+
 {{ configsetting("INVENTREE_DB_OPTIONS") }} Additional database options (as a JSON object) |
 
 !!! tip "Database Password"
@@ -266,11 +269,12 @@ The following database options can be configured:
 If running with a PostgreSQL database backend, the following additional options are available:
 
 {{ configtable() }}
-{{ configsetting("INVENTREE_DB_TIMEOUT", default="2") }} Database connection timeout (s) |
+{{ configsetting("INVENTREE_DB_TIMEOUT", default="10") }} Database connection timeout (s) |
 | `INVENTREE_DB_TCP_KEEPALIVES` | database.tcp_keepalives | 1 | TCP keepalive |
-| `INVENTREE_DB_TCP_KEEPALIVES_IDLE` | database.tcp_keepalives_idle | 1 | Idle TCP keepalive |
+| `INVENTREE_DB_TCP_KEEPALIVES_IDLE` | database.tcp_keepalives_idle | 5 | Idle TCP keepalive |
-| `INVENTREE_DB_TCP_KEEPALIVES_INTERVAL` | database.tcp_keepalives_interval | 1| TCP keepalive interval |
+| `INVENTREE_DB_TCP_KEEPALIVES_INTERVAL` | database.tcp_keepalives_interval | 5 | TCP keepalive interval |
 | `INVENTREE_DB_TCP_KEEPALIVES_COUNT` | database.tcp_keepalives_count | 5 | TCP keepalive count |
+| `INVENTREE_DB_TCP_USER_TIMEOUT` | database.tcp_user_timeout | 2000 | TCP user timeout (ms) |
 | `INVENTREE_DB_ISOLATION_SERIALIZABLE` | database.serializable | False | Database isolation level configured to "serializable" |
 
 ### MySQL Settings
@@ -278,6 +282,7 @@ If running with a PostgreSQL database backend, the following additional options
 If running with a MySQL database backend, the following additional options are available:
 
 {{ configtable() }}
+{{ configsetting("INVENTREE_DB_TIMEOUT", default="10") }} Database connection timeout (s) |
 | `INVENTREE_DB_ISOLATION_SERIALIZABLE` | database.serializable | False | Database isolation level configured to "serializable" |
 
 ### SQLite Settings

src/backend/InvenTree/InvenTree/setting/db_backend.py

@@ -5,10 +5,23 @@ from pathlib import Path
 import structlog
 
 from InvenTree.config import get_boolean_setting, get_config_value, get_setting
+from InvenTree.ready import isInWorkerThread
 
 logger = structlog.get_logger('inventree')
 
 
+def _get_conn_max_age() -> int | None:
+    """Return the configured CONN_MAX_AGE value.
+
+    Accepts an integer number of seconds, or 'None' for unlimited persistence.
+    Defaults to 0 (close the connection after each request).
+    """
+    value = get_setting('INVENTREE_DB_CONN_MAX_AGE', 'database.conn_max_age', 0)
+    if value is None or str(value).strip().lower() == 'none':
+        return None
+    return int(value)
+
+
 def get_db_backend():
     """Return the database backend configuration."""
     # For the core database configuration values, we test for UPPERCASE configuration values as a backup,
@@ -43,6 +56,13 @@ def get_db_backend():
         )
         or get_config_value('database.OPTIONS')
         or {},
+        # Seconds to keep idle connections open across requests (0 = close after each request).
+        # Set to None for unlimited. Enable CONN_HEALTH_CHECKS alongside any non-zero value
+        # so stale connections are detected before use rather than causing request failures.
+        'CONN_MAX_AGE': _get_conn_max_age(),
+        'CONN_HEALTH_CHECKS': get_boolean_setting(
+            'INVENTREE_DB_CONN_HEALTH_CHECKS', 'database.conn_health_checks', False
+        ),
     }
 
     # Check for required keys
@@ -113,9 +133,9 @@ def set_postgres_options(db_options: dict):
     if 'connect_timeout' not in db_options:
         # The DB server is in the same data center, it should not take very
         # long to connect to the database server
-        # # seconds, 2 is minimum allowed by libpq
+        # Note: 2 seconds is minimum allowed by libpq
-        db_options['connect_timeout'] = int(
+        db_options['connect_timeout'] = max(
-            get_setting('INVENTREE_DB_TIMEOUT', 'database.timeout', 2)
+            2, int(get_setting('INVENTREE_DB_TIMEOUT', 'database.timeout', 10))
         )
 
     # Setup TCP keepalive
@@ -133,7 +153,7 @@ def set_postgres_options(db_options: dict):
     if 'keepalives_idle' not in db_options:
         db_options['keepalives_idle'] = int(
             get_setting(
-                'INVENTREE_DB_TCP_KEEPALIVES_IDLE', 'database.tcp_keepalives_idle', 1
+                'INVENTREE_DB_TCP_KEEPALIVES_IDLE', 'database.tcp_keepalives_idle', 5
             )
         )
 
@@ -143,7 +163,7 @@ def set_postgres_options(db_options: dict):
             get_setting(
                 'INVENTREE_DB_TCP_KEEPALIVES_INTERVAL',
                 'database.tcp_keepalives_interval',
-                '1',
+                '5',
             )
         )
 
@@ -157,10 +177,13 @@ def set_postgres_options(db_options: dict):
             )
         )
 
-    # # Milliseconds for how long pending data should remain unacked
+    # # Milliseconds for how long pending data should remain unacked by the remote server
-    # by the remote server
+    if 'tcp_user_timeout' not in db_options:
-    # TODO: Supported starting in PSQL 11
+        db_options['tcp_user_timeout'] = int(
-    # "tcp_user_timeout": int(os.getenv("PGTCP_USER_TIMEOUT", "1000"),
+            get_setting(
+                'INVENTREE_DB_TCP_USER_TIMEOUT', 'database.tcp_user_timeout', '2000'
+            )
+        )
 
     # Postgres's default isolation level is Read Committed which is
     # normally fine, but most developers think the database server is
@@ -178,10 +201,21 @@ def set_postgres_options(db_options: dict):
             else IsolationLevel.READ_COMMITTED
         )
 
+    # Specify the application name for the database connection
+    # This can be useful for debugging and monitoring purposes
+    if 'application_name' not in db_options:
+        db_options['application_name'] = (
+            'inventree-worker' if isInWorkerThread() else 'inventree-server'
+        )
+
 
 def set_mysql_options(db_options: dict):
     """Set database options specific to mysql backend."""
-    # TODO TCP time outs and keepalives
+    # Timeout values
+    if 'connect_timeout' not in db_options:
+        db_options['connect_timeout'] = int(
+            get_setting('INVENTREE_DB_TIMEOUT', 'database.timeout', 10)
+        )
 
     # MariaDB's default isolation level is Repeatable Read which is
     # normally fine, but most developers think the database server is