Re: [cx-oracle-users] ping()

[Paul M. <p.f...@gm...>]

2011/1/17  <prz...@po...>:
> I have changed the code to:
>
> try:
>    con = cx_Oracle.connect('publikator/gre1czech0@HP_42_OL')
>    con.ping()
> except cx_Oracle.DatabaseError:
>    #print "*** Connection dropped ***"
>    STATUS = "DOWN"
> else:
>    STATUS= "UP"
>
> Should I avoid "cx_Oracle.DatabaseError" in the "except" clause ?

I'd personally be inclined to do something like

try:
   con = cx_Oracle.connect('xxx/yyy@zzz')
   STATUS= "UP"
   con.close()
except cx_Oracle.DatabaseError as ex:
   # check ex.args[0].code to make sure it's an error that means the
DB is down, rather than
   # something else like incorrect password...
   if ex.args[0].code in (...):
      STATUS = "DOWN"
   else:
      # Unexpected error - report it somehow (I'll just reraise here)
      raise
except Exception:
      # Unexpected error - report it somehow (I'll just reraise here -
if you are just going
      # to reraise you can omit this whole clause)
      raise

I tend to be paranoid about not letting unexpected conditions go
unreported or caught inappropriately, which is what I suspect is
happening to you here.

By the way, what results did you get from the tests I suggested below?

>> Or your database is actually up... (what Oracle logs are you looking
>> at to see that the database is down?)
>
> alert log

Of course even if the alert log shows the database as up, the listener
might be down...

>> You might want to check that the database is showing as down if you
>> connect to it via SQL*Plus. If it is, try the connect() call in the
>> interactive interpreter and see what it returns. That may help you to
>> diagnose the problem better.

Paul.