Fix orphan database connections resulting in an inability to connect to databases. #5567

web/config.py

@@ -837,6 +837,13 @@ ENABLE_BINARY_PATH_BROWSING = False
 #############################################################################
 AUTO_DISCOVER_SERVERS = True
 
+#############################################################################
+# SERVER_HEARTBEAT_TIMEOUT is used to send the server heartbeat to server
+# from the client. This will resolve the orphan database issue once
+# browser tab is closed.
+#############################################################################
+SERVER_HEARTBEAT_TIMEOUT = 30  # In seconds
+
 ##########################################################################
 # Local config settings
 ##########################################################################

web/pgadmin/__init__.py

@@ -37,7 +37,7 @@ from jinja2 import select_autoescape
 
 from pgadmin.model import db, Role, Server, SharedServer, ServerGroup, \
     User, Keys, Version, SCHEMA_VERSION as CURRENT_SCHEMA_VERSION
-from pgadmin.utils import PgAdminModule, driver, KeyManager
+from pgadmin.utils import PgAdminModule, driver, KeyManager, heartbeat
 from pgadmin.utils.preferences import Preferences
 from pgadmin.utils.session import create_session_interface, pga_unauthorised
 from pgadmin.utils.versioned_template_loader import VersionedTemplateLoader
@@ -49,6 +49,7 @@ from pgadmin import authenticate
 from pgadmin.utils.security_headers import SecurityHeaders
 from pgadmin.utils.constants import KERBEROS, OAUTH2, INTERNAL, LDAP, WEBSERVER
 
+
 # Explicitly set the mime-types so that a corrupted windows registry will not
 # affect pgAdmin 4 to be load properly. This will avoid the issues that may
 # occur due to security fix of X_CONTENT_TYPE_OPTIONS = "nosniff".
@@ -541,6 +542,7 @@ def create_app(app_name=None):
     ##########################################################################
     driver.init_app(app)
     authenticate.init_app(app)
+    heartbeat.init_app(app)
 
     ##########################################################################
     # Register language to the preferences after login

web/pgadmin/browser/__init__.py

@@ -626,7 +626,8 @@ def utils():
             is_admin=current_user.has_role("Administrator"),
             login_url=login_url,
             username=current_user.username,
-            auth_source=auth_source
+            auth_source=auth_source,
+            heartbeat_timeout=config.SERVER_HEARTBEAT_TIMEOUT
         ),
         200, {'Content-Type': MIMETYPE_APP_JS})
 

web/pgadmin/browser/server_groups/servers/static/js/server.js

@@ -786,6 +786,10 @@ define('pgadmin.node.server', [
             if(data.errmsg) {
               Notify.error(data.errmsg);
             }
+            // Generate the event that server is connected
+            pgBrowser.Events.trigger(
+              'pgadmin:server:connected', data._id, item, data
+            );
           }
         })
         .fail(function(xhr, status, error) {

web/pgadmin/browser/static/js/browser.js

@@ -15,6 +15,7 @@ import Notify, {initializeModalProvider, initializeNotifier} from '../../../stat
 import { checkMasterPassword } from '../../../static/js/Dialogs/index';
 import { pgHandleItemError } from '../../../static/js/utils';
 import { Search } from './quick_search/trigger_search';
+import { send_heartbeat } from './heartbeat';
 
 define('pgadmin.browser', [
   'sources/gettext', 'sources/url_for', 'require', 'jquery',
@@ -581,6 +582,10 @@ define('pgadmin.browser', [
           .fail(function() {/*This is intentional (SonarQube)*/});
       }, 300000);
 
+      obj.Events.on(
+        'pgadmin:server:connected', send_heartbeat.bind(obj)
+      );
+
       obj.set_master_password('');
       obj.check_corrupted_db_file();
       obj.Events.on('pgadmin:browser:tree:add', obj.onAddTreeNode.bind(obj));

web/pgadmin/browser/static/js/heartbeat.js

@@ -0,0 +1,31 @@
+/////////////////////////////////////////////////////////////
+//
+// pgAdmin 4 - PostgreSQL Tools
+//
+// Copyright (C) 2013 - 2023, The pgAdmin Development Team
+// This software is released under the PostgreSQL Licence
+//
+//////////////////////////////////////////////////////////////
+
+import gettext from 'sources/gettext';
+import url_for from 'sources/url_for';
+import getApiInstance from '../../../static/js/api_instance';
+import Notifier from '../../../static/js/helpers/Notifier';
+import pgAdmin from 'sources/pgadmin';
+
+const axiosApi = getApiInstance();
+let HEARTBEAT_TIMEOUT = pgAdmin.heartbeat_timeout * 1000;
+
+export function send_heartbeat(_server_id) {
+  // Send heartbeat to the server every 30 seconds
+  setInterval(function() {
+    axiosApi.post(url_for('misc.heartbeat'), {'sid': _server_id})
+      .then(() => {
+        // pass
+      })
+      .catch((error) => {
+        Notifier.error(gettext(`pgAdmin server not responding, try to login again: ${error.message || error.response.data.errormsg}`));
+      });
+
+  }, HEARTBEAT_TIMEOUT);
+}

web/pgadmin/browser/templates/browser/js/utils.js

@@ -66,6 +66,9 @@ define('pgadmin.browser.utils',
   /* GET the pgadmin server's locale */
   pgAdmin['pgadmin_server_locale'] =  '{{pgadmin_server_locale}}';
 
+   /* Server Heartbeat Timeout */
+  pgAdmin['heartbeat_timeout'] =  '{{heartbeat_timeout}}';
+
   // Define list of nodes on which Query tool option doesn't appears
   let unsupported_nodes = pgAdmin.unsupported_nodes = [
      'server_group', 'server', 'coll-tablespace', 'tablespace',

web/pgadmin/misc/__init__.py

@@ -19,6 +19,7 @@ from pgadmin.utils.session import cleanup_session_files
 from pgadmin.misc.themes import get_all_themes
 from pgadmin.utils.constants import MIMETYPE_APP_JS, UTILITIES_ARRAY
 from pgadmin.utils.ajax import precondition_required, make_json_response
+from pgadmin.utils.heartbeat import log_server_heartbeat, get_server_heartbeat
 import config
 import subprocess
 import os
@@ -93,7 +94,8 @@ class MiscModule(PgAdminModule):
             list: a list of url endpoints exposed to the client.
         """
         return ['misc.ping', 'misc.index', 'misc.cleanup',
-                'misc.validate_binary_path']
+                'misc.validate_binary_path', 'misc.heartbeat',
+                'misc.get_heartbeat']
 
     def register(self, app, options):
         """
@@ -156,6 +158,29 @@ def cleanup():
     return ""
 
 
+@blueprint.route("/heartbeat", methods=['POST'])
+@pgCSRFProtect.exempt
+def heartbeat():
+    data = None
+    if hasattr(request.data, 'decode'):
+        data = request.data.decode('utf-8')
+
+    if data != '':
+        data = json.loads(data)
+
+    log_server_heartbeat(data)
+    return make_json_response(data=gettext('Heartbeat logged successfully.'),
+                              status=200)
+
+
+@blueprint.route("/get_heartbeat/<int:sid>", methods=['GET'])
+@pgCSRFProtect.exempt
+def get_heartbeat(sid):
+    heartbeat_data = get_server_heartbeat(sid)
+    return make_json_response(data=heartbeat_data,
+                              status=200)
+
+
 @blueprint.route("/explain/explain.js")
 def explain_js():
     """

web/pgadmin/utils/driver/__init__.py

@@ -30,7 +30,5 @@ def init_app(app):
 
 
 def ping():
-    drivers = getattr(current_app, '_pgadmin_server_drivers', None)
-
-    for type in drivers:
-        drivers[type].gc_timeout()
+    for type in DriverRegistry._registry:
+        DriverRegistry._objects[type].gc_timeout()

web/pgadmin/utils/heartbeat.py

@@ -0,0 +1,107 @@
+##########################################################################
+#
+# pgAdmin 4 - PostgreSQL Tools
+#
+# Copyright (C) 2013 - 2023, The pgAdmin Development Team
+# This software is released under the PostgreSQL Licence
+#
+#########################################################################
+
+"""Server heartbeat manager."""
+
+
+import threading
+import datetime
+import config
+from flask import session, current_app
+
+
+def log_server_heartbeat(data):
+    """Log Server Heartbeat."""
+    from config import PG_DEFAULT_DRIVER
+    from pgadmin.utils.driver import get_driver
+    manager = get_driver(PG_DEFAULT_DRIVER).connection_manager(int(data['sid'])
+                                                               )
+
+    _server_heartbeat = getattr(current_app, '_pgadmin_server_heartbeat', {})
+
+    if session.sid not in _server_heartbeat:
+        _server_heartbeat[session.sid] = {}
+
+    _server_heartbeat[session.sid][data['sid']] = {
+        'timestamp': datetime.datetime.now(),
+        'conn': manager.connections
+    }
+
+    setattr(current_app, '_pgadmin_server_heartbeat', _server_heartbeat)
+
+    current_app.logger.debug(
+        "Heartbeat logged for the session id##server id: {0}##{1}".format(
+            session.sid, data['sid']))
+
+
+def get_server_heartbeat(server_id):
+    _server_heartbeat = getattr(current_app, '_pgadmin_server_heartbeat', {})
+
+    if session.sid in _server_heartbeat and server_id in _server_heartbeat[
+            session.sid]:
+        return _server_heartbeat[session.sid][server_id]
+    else:
+        return None
+
+
+class ServerHeartbeatTimer():
+    def __init__(self, sec, _app):
+        def func_wrapper():
+            self.t = threading.Timer(sec, func_wrapper)
+            self.t.start()
+            self.release_server_heartbeat()
+        self.t = threading.Timer(sec, func_wrapper)
+        self.t.start()
+        self._app = _app
+
+    def release_server_heartbeat(self):
+        with self._app.app_context():
+            _server_heartbeat = getattr(self._app,
+                                        '_pgadmin_server_heartbeat', {})
+            if len(_server_heartbeat) > 0:
+                for sess_id in list(_server_heartbeat):
+                    for sid in list(_server_heartbeat[sess_id]):
+                        last_heartbeat_time = _server_heartbeat[sess_id][sid][
+                            'timestamp']
+                        current_time = datetime.datetime.now()
+                        diff = current_time - last_heartbeat_time
+
+                        # Wait for 4 times then the timeout
+                        if diff.total_seconds() > (
+                                config.SERVER_HEARTBEAT_TIMEOUT * 4):
+                            self._release_connections(
+                                _server_heartbeat[sess_id][sid]['conn'],
+                                sess_id, sid)
+                            _server_heartbeat[sess_id].pop(sid)
+                            if len(_server_heartbeat[sess_id]) == 0:
+                                _server_heartbeat.pop(sess_id)
+                setattr(self._app, '_pgadmin_server_heartbeat',
+                        _server_heartbeat)
+
+    @staticmethod
+    def _release_connections(server_conn, sess_id, sid):
+        for d in server_conn:
+            # Release the connection
+            server_conn[d]._release()
+            # Reconnect on the reload
+            server_conn[d].wasConnected = True
+            current_app.logger.debug(
+                "Heartbeat not received. Released "
+                "connection for the session "
+                "id##server id: {0}##{1}".format(
+                    sess_id, sid))
+
+    def cancel(self):
+        self.t.cancel()
+
+
+def init_app(app):
+    setattr(app, '_pgadmin_server_heartbeat', {})
+    ServerHeartbeatTimer(sec=config.SERVER_HEARTBEAT_TIMEOUT,
+                         _app=app)