pgadmin4/web/pgadmin/utils/exception.py
Ashesh Vashi f12d981a9d Handling the bad/lost connection of a database server.
Made backend changes for:
* Taking care of the connection status in the psycopg2 driver. And, when
  the connection is lost, it throws a exception with 503 http status
  message, and connection lost information in it.
* Allowing the flask application to propagate the exceptions even in the
  release mode.
* Utilising the existing password (while reconnection, if not
  disconnected explicitly).
* Introduced a new ajax response message 'service_unavailable' (http
  status code: 503), which suggests temporary service unavailable.

Client (front-end) changes:
* To handle the connection lost of a database server for different
  operations by generating proper events, and handle them properly.

Removed the connection status check code from different nodes, so that
- it generates the proper exception, when accessing the non-alive
  connection.

Fixes #1387
2016-08-29 12:01:35 +05:30

43 lines
1.2 KiB
Python

##########################################################################
#
# pgAdmin 4 - PostgreSQL Tools
#
# Copyright (C) 2013 - 2016, The pgAdmin Development Team
# This software is released under the PostgreSQL Licence
#
##########################################################################
from werkzeug.exceptions import HTTPException
from werkzeug.http import HTTP_STATUS_CODES
from flask_babel import gettext as _
from flask import request
from pgadmin.utils.ajax import service_unavailable
class ConnectionLost(HTTPException):
"""
Exception
"""
def __init__(self, _server_id, _database_name, _conn_id):
self.sid = _server_id
self.db = _database_name
self.conn_id = _conn_id
HTTPException.__init__(self)
@property
def name(self):
return HTTP_STATUS_CODES.get(505, 'Service Unavailable')
def get_response(self, environ=None):
return service_unavailable(
_("Connection to the server has been lost!"),
info="CONNECTION_LOST",
data={
'sid': self.sid,
'database': self.db,
'conn_id': self.conn_id
}
)