Thursday, December 15, 2011

EMAIL NOTIFICATION changes in init.ora parameters


Auditing changes to init.ora parameters (via pfile or spfile) is an important DBA task. Sometimes, users which have “alter system” privilege can make unauthorized changes to the initialization parameters in the spfile on a production database. Hence, auditing changes to parameters is a critical DBA task. Fortunately, it's quite simple to audit these changes by implementing the audit_sys_operations=true.

Here is a method to track changes to the initialization parameters. In order to track all changes to parameters we can use audit for thealter system statement for any specific user

We should follow below steps to track changes to init.ora parameters:

1. ALTER SYSTEM SET audit_trail=db SCOPE=SPFILE;
2. SHUTDOWN IMMEDIATE
3. STARTUP
4. CREATE USER TEST IDENTIFIED BY TEST;
5. GRANT DBA TO TEST;
6. AUDIT ALTER SYSTEM BY test;
7. CONN TEST/TEST
8. ALTER SYSTEM SET AUDIT_TRAIL=db SCOPE=SPFILE;

9. Create an alert script to notify the DBA when a parameter has changed.

Let's start by finding the action_name in the dba_audit_trail view for the alter system command:

SQL> select username, timestamp, action_name from dba_audit_trail;

USERNAME TIMESTAMP ACTION_NAME
------------------------------ ------------- ----------------------------
TEST 29-MAY-09 ALTER SYSTEM


STEP 1
- We can track changes made by SYS user by setting audit_sys_operations parameter to TRUE.

SQL> alter system set audit_sys_operations=true scope=spfile;
System altered.

STEP 2 - Next, we bounce the instance to make the change take effect:
SQL> shutdown immediate
Database closed.
Database dismounted.
ORACLE instance shut down.

SQL> startup
ORACLE instance started.
Total System Global Area 285212672 bytes
Fixed Size 1218992 bytes
Variable Size 92276304 bytes
Database Buffers 188743680 bytes
Redo Buffers 2973696 bytes
Database mounted.
Database opened.

Here we see our auditing parameters:
SQL> show parameter audit
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
audit_file_dest string /home/oracle/oracle/product/10 .2.0/db_1/admin/fkhalid/adump
audit_sys_operations boolean TRUE
audit_syslog_level string
audit_trail string DB

SQL> alter system set audit_trail=db scope=spfile;
System altered.

STEP 3 - Here we go to the adump directory and examine the audit files:
SQL> host
[oracle@localhost bin]$ cd /home/oracle/oracle/product/10.2.0/db_1/admin/kam/adump/

[oracle@localhost adump]$ ls
ora_5449.aud ora_5476.aud ora_5477.aud ora_5548.aud ora_5575.aud ora_5576.aud

[oracle@localhost adump]$ cat ora_5576.aud
Audit file /home/oracle/oracle/product/10.2.0/db_1/admin/kam/adump/ora_5576.aud
Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Production
With the Partitioning, OLAP and Data Mining options
ORACLE_HOME = /home/oracle/oracle/product/10.2.0/db_1/
System name: Linux
Node name: localhost.localdomain
Release: 2.6.18-92.el5
Version: #1 SMP Tue Jun 10 18:49:47 EDT 2008
Machine: i686
Instance name: kam
Redo thread mounted by this instance: 1
Oracle process number: 15
Unix process pid: 5576, image: oracle@localhost.localdomain (TNS V1-V3)
Fri May 29 02:38:30 2009
ACTION : 'alter system set audit_trail=db scope=spfile'
DATABASE USER: '/'
PRIVILEGE : SYSDBA
CLIENT USER: oracle
CLIENT TERMINAL: pts/2
STATUS: 0

STEP 4 - Now, create a crontab job to seek new entries in the adump directory.
#******************************************************
# list the full-names of all possible adump files . . . .
#******************************************************
rm -f /tmp/audit_list.lst
find $DBA/$ORACLE_SID/adump/*.trc -mtime -1 -print >> /tmp/audit_list.lst
STEP 5 - When found, send the DBA an e-mail:
# If initialization paramneter has changed, send an e-mail
if [ -f /tmp/audit_list.lst]; then
then
# Now, be sure that we don't clog the mailbox.
# the following statement checks to look for existing mail,
# and only sends mail when mailbox is empty . . .
if [ ! -s /var/spool/mail/oramy_sid ]
then
cat /oracle/MY_SID/scripts/oracheck.log | mail oramy_sid
fi
sendmail . . .
fi

Please beware that using the auditing command imposes additional work on the production database.

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