cx_Oracle._Error in Python script

Question

I have attempted to search for a resolution or at least a few troubleshooting steps to understand why I see these errors when I execute a Python script. No luck so far. I SSH to Rackspace to do this.

The errors reference the Oracle db. To be more specific, it is cx_Oracle._Error and cx_Oracle.DatabaseError on separate occasions. Below is an example of a few lines from the server logs. It does not give any more information than that.

Running against Oracle server: prod.somecompanyname + prod123
Error connecting to databases: (<cx_Oracle._Error object at0x7ffff7fe9af8>,) 
Error verifying existing Oracle records

My colleague is able to execute the script successfully and does not encounter the error. I compared our .bash_profile and .bashrc and nothing different stands out. The Oracle server credentials are correct in the script as well as the Oracle environment path. This may be isolated to something on my end however I cannot figure out where.

Any suggestions on where to look to fix this is appreciated.

def oraclerecords(logger, env, db1Pass, db2Pass, db3Pass, verifyRecordset):
  import cx_Oracle
  retval = None

  try:
    db1UID='somedb1name'
    db2UID='somedb2name'
    if env == 'p':
      dbServer='prod.somecompanyname.com'
      dbSID='SIDPR'
    elif env == 's':
      dbServer='stage.somecompanyname.com'
      dbSID='SIDSTG'
    elif env == 'r':
      dbServer='stage.somecompanyname.com'
      dbSID='SIDDEV'

    db3UID = 'somedb3name'
    db3SID = 'db3HUB'

    logger.info('Running against Oracle server:' + dbServer + ' SID:' + dbSID)
    connString = (db1UID + '/' + db1Pass + '@(DESCRIPTION=(ADDRESS_LIST=(ADDRESS='
      '(PROTOCOL=TCP)(HOST=' + dbServer + ')(PORT=1234)))(CONNECT_DATA=(SID=' + dbSID + ')))')
    conndb1 = cx_Oracle.connect(connString)
    curdb1 = conndb1.cursor()
    curdb0 = conndb1.cursor()

    connString = (db2UID + '/' + db2Pass + '@(DESCRIPTION=(ADDRESS_LIST=(ADDRESS='
      '(PROTOCOL=TCP)(HOST=' + dbServer + ')(PORT=1234)))(CONNECT_DATA=(SID=' + dbSID + ')))')
    conndb2 = cx_Oracle.connect(connString)
    curdb2 = conndb2.cursor()

    connString = (db3UID + '/' + db3Pass + '@(DESCRIPTION=(ADDRESS_LIST=(ADDRESS='
      '(PROTOCOL=TCP)(HOST=prod.atsomecompany.com)(PORT=1234)))(CONNECT_DATA=(SID=' + db3SID + ')))')
    conndb3 = cx_Oracle.connect(connString)
    curdb3 = conndb3.cursor()
  except Exception as e:
    logger.error('Error connecting to databases: ' + str(e.args))
    return verifyRecordset, 2

I would say the problem here is poor error handling in the script you are running. Without sharing this script, or at the very least the part of it that prints out the line Error connecting to databases: ... I really don't see how anybody can help you here. — Luke Woodward
– Luke Woodward, Commented Jan 12, 2015 at 22:35
Thanks Luke. With the try-except statement, it will just capture the exception that occurs but will not give me the root cause. Hope this code somewhat helps. — Alice Chiu
– Alice Chiu, Commented Jan 14, 2015 at 20:09

Luke Woodward · Accepted Answer · 2015-01-14 22:33:32Z

The issue with your Python script is on this line:

  logger.error('Error connecting to databases: ' + str(e.args))

Perhaps the simplest way to improve it is to replace it with the following:

  logger.error('Error connecting to databases: ' + str(e))

I wrote the following short Python script that attempts to connect to an Oracle XE database:

import cx_Oracle

connect_string = "..."
try:
    conn = cx_Oracle.connect(connect_string)
    print "Got connection"
except Exception as e:
    print str(e.args)
    print str(e)

I knew this script would raise an exception because the database and the listener it was attempting to connect to were both down. When I ran, it I got the following output:

(<cx_Oracle._Error object at 0x02354308>,)
ORA-12541: TNS:no listener

The first line here doesn't tell me anything helpful, but the second line contains a more useful message.

Hopefully after making this change to your script you will see a more useful error message, which should help you track down what the real problem is here.

Collectives™ on Stack Overflow

cx_Oracle._Error in Python script

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related