On Mon, 14 Feb 2005 21:50:57 +0100, Michal Chruszcz <troll@pld-linux.org> wrote:
Hello,
I've noticed a bug(?) or at least misbehaviour in adapi connection pool. I've got a daemon program which keeps a few connections to PostgreSQL database and when a client connects and sends some commands it queries the database and sends back results. Everything works fine, until I restart PostgreSQL. All commands fail and the only trace I've got is the response from the database:
Attempting reconnects just isn't part of adbapi as far as I can tell. I use psycopg with postgresql and here is how I handle this, maybe someone else has a better way of doing it. This tests the database connection every 10 seconds, and attempts to reconnect 3 times if it gets an error, otherwise it exits. It's not very complete but that's because I just threw it together today... In my server factory: ----------------------------------- class Somefactory(Factory): def __init__(self): self.db = 'dbname' self.dbhost = 'dbhostname' self.reconnect = 1 self.dbpool = adbapi.ConnectionPool() loop1 = task.LoopingCall(self.checkDatabase) loop1.start(10.0) # call every 10 seconds def _cbdatabaseError(self,error): error_msg = error.getBriefTraceback() if re.search('psycopg.OperationalError',error_msg): if self.reconnect <= 3: self.dbpool = adbapi.ConnectionPool() self.reconnect = self.reconnect + 1 else: reactor.stop() else: reactor.stop() def _cbdatabaseAlive(self,msg): self.reconnect = 1 def checkDatabase(self): d = self.dbpool.runInteraction(self._cbcheckDatabase) d.addCallbacks(self._cbdatabaseAlive,self._cbdatabaseError) def _cbcheckDatabase(self,cursor): sql = "SELECT 1" cursor.execute(sql) row = cursor.fetchall() return row