Set database connection timeout in Python

Question

I\'m creating a RESTful API which needs to access the database. I\'m using Restish, Oracle, and SQLAlchemy. However, I\'ll try to frame my question as generically as possi

Answer 1

Timing Out with the System Alarm

Here's how to use the operating system timout to do this. It's generic, and works for things other than Oracle.

import signal
class TimeoutExc(Exception):
    """this exception is raised when there's a timeout"""
    def __init__(self): Exception.__init__(self)
def alarmhandler(signame,frame):
    "sigalarm handler.  raises a Timeout exception"""
    raise TimeoutExc()

nsecs=5
signal.signal(signal.SIGALRM, alarmhandler)  # set the signal handler function
signal.alarm(nsecs)                          # in 5s, the process receives a SIGALRM
try:
    cx_Oracle.connect(blah blah)             # do your thing, connect, query, etc
    signal.alarm(0)                          # if successful, turn of alarm
except TimeoutExc:
    print "timed out!"                       # timed out!!

Answer 2

for the query, you can look on timer and conn.cancel() call.

something in those lines:

t = threading.Timer(timeout,conn.cancel)
t.start()
cursor = conn.cursor()
cursor.execute(query)
res =  cursor.fetchall()
t.cancel()

Answer 3

You could look at setting up PROFILEs in Oracle to terminate the queries after a certain number of logical_reads_per_call and/or cpu_per_call

Answer 4

In linux see /etc/oracle/sqlnet.ora,

sqlnet.outbound_connect_timeout= value

also have options:

tcp.connect_timeout and sqlnet.expire_time, good luck!