Introduction

This article focuses on the DBA's daily responsibilities for monitoring  Oracle databases and provides tips and techniques on how DBAs can turn their  manual, reactive monitoring activities into a set of proactive shell scripts.  The article first reviews some commonly used Unix commands by DBAs. It explains  the Unix Cron jobs that are used as part of the scheduling mechanism to execute  DBA scripts. The article covers eight important scripts for monitoring Oracle  database:

• Check instance availability

• Check listener availability

• Check alert log files for error messages

• Clean up old log files before log destination gets filled

• Analyze tables and indexes for better performance

• Check tablespace usage

• Find out invalid objects

• Monitor users and transactions

UNIX Basics for the DBA

Basic UNIX Command

The following is a list of commonly used Unix command:

• ps - Show process

• grep - Search files for text patterns

• mailx - Read or send mail

• cat - Join files or display them

• cut - Select columns for display

• awk - Pattern-matching language

• df - Show free disk space

Here are some examples of how the DBA uses these commands:

• List available instances on a server:

$ ps -ef | grep smon
  oracle 21832     1  0   Feb 24 ?       19:05 ora_smon_oradb1
  oracle   898     1  0   Feb 15 ?        0:00 ora_smon_oradb2
    dliu 25199 19038  0 10:48:57 pts/6    0:00 grep smon
  oracle 27798     1  0 05:43:54 ?        0:00 ora_smon_oradb3
  oracle 28781     1  0   Mar 03 ?        0:01 ora_smon_oradb4

• List available listeners on a server:

$ ps -ef | grep listener | grep -v grep
  oracle 23879    1  0   Feb 24 ?  33:36 /8.1.7/bin/tnslsnr listener_db1 -inherit
  oracle 27939    1  0 05:44:02 ?  0:00  /8.1.7/bin/tnslsnr listener_db2 -inherit
  oracle 23536    1  0   Feb 12 ?  4:19  /8.1.7/bin/tnslsnr listener_db3 -inherit
  oracle 28891    1  0   Mar 03 ?  0:01  /8.1.7/bin/tnslsnr listener_db4 -inherit

• Find out file system usage for Oracle archive  destination:

$ df -k | grep oraarch
  /dev/vx/dsk/proddg/oraarch 71123968 4754872 65850768  7%  /u09/oraarch

• List number of lines in the alert.log file:

$ cat alert.log | wc -l
   2984

• List all Oracle error messages from the alert.log file:

$ grep ORA- alert.log
  ORA-00600: internal error code, arguments: [kcrrrfswda.1], [], [], [], [], []
  ORA-00600: internal error code, arguments: [1881], [25860496], [25857716], []

CRONTAB Basics

A crontab file is comprised of six fields:

Minute	0-59
Hour	0-23
Day of month	1-31
Month	1 - 12
Day of Week	0 - 6, with 0 = Sunday
Unix Command or Shell Scripts

• To edit a crontab file, type:

Crontab -e

• To view a crontab file, type:

Crontab -l

0  4 * * 5       /dba/admin/analyze_table.ksh
     30 3  * * 3,6    /dba/admin/hotbackup.ksh /dev/null 2>&1

In the example above, the first entry shows that a script. to analyze a table  runs every Friday at 4:00 a.m. The second entry shows that a script. to perform. a  hot backup runs every Wednesday and Saturday at 3:00 a.m.

Top DBA Shell Scripts for Monitoring the Database

The eight shell scripts provided below cover 90 percent of a DBA's daily  monitoring activities. You will need to modify the UNIX environment variables as  appropriate.

Check Oracle Instance Availability

The oratab file lists all the databases on a server:

$ cat /var/opt/oracle/oratab
###################################################################
## /var/opt/oracle/oratab                                        ##
###################################################################
oradb1:/u01/app/oracle/product/8.1.7:Y
oradb2:/u01/app/oracle/product/8.1.7:Y
oradb3:/u01/app/oracle/product/8.1.7:N
oradb4:/u01/app/oracle/product/8.1.7:Y

The following script. checks all the databases listed in the oratab file, and  finds out the status (up or down) of databases:

###################################################################
## ckinstance.ksh ##
###################################################################
ORATAB=/var/opt/oracle/oratab
echo "`date`   "
echo  "Oracle Database(s) Status `hostname` :\n"

db=`egrep -i ":Y|:N" $ORATAB | cut -d":" -f1 | grep -v "\#" | grep -v "\*"`
pslist="`ps -ef | grep pmon`"
for i in $db ; do
  echo  "$pslist" | grep  "ora_pmon_$i"  > /dev/null 2>$1
  if (( $? )); then
        echo "Oracle Instance - $i:       Down"
  else
        echo "Oracle Instance - $i:       Up"
  fi
done

Use the following to make sure the script. is executable:

$ chmod 744 ckinstance.ksh
$ ls -l ckinstance.ksh
-rwxr--r--   1 oracle     dba     657 Mar  5 22:59 ckinstance.ksh*

Here is an instance availability report:

$ ckinstance.ksh
Mon Mar  4 10:44:12 PST 2002

Oracle Database(s) Status for DBHOST server:
Oracle Instance - oradb1:   Up
Oracle Instance - oradb2:   Up
Oracle Instance - oradb3:   Down
Oracle Instance - oradb4:   Up

Check Oracle Listener's Availability

A similar script. checks for the Oracle listener. If the listener is down, the  script. will restart the listener:

#######################################################################
## cklsnr.sh                                                         ##
#######################################################################
#!/bin/ksh
DBALIST="primary.dba@company.com,another.dba@company.com";export DBALIST
cd /var/opt/oracle
rm -f lsnr.exist
ps -ef | grep mylsnr | grep -v grep  > lsnr.exist
if [ -s lsnr.exist ]
then
    echo
else
echo "Alert" | mailx -s "Listener 'mylsnr' on `hostname` is down" $DBALIST
    TNS_ADMIN=/var/opt/oracle; export TNS_ADMIN
    ORACLE_SID=db1; export ORACLE_SID  
    ORAENV_ASK=NO; export ORAENV_ASK
    PATH=$PATH:/bin:/usr/local/bin; export PATH
    . oraenv
    LD_LIBRARY_PATH=${ORACLE_HOME}/lib;export LD_LIBRARY_PATH
    lsnrctl start mylsnr
fi

Check Alert Logs (ORA-XXXXX)

Some of the environment variables used by each script. can be put into one  profile:

#######################################################################
## oracle.profile ##
#######################################################################
EDITOR=vi;export EDITOR ORACLE_BASE=/u01/app/oracle; export
ORACLE_BASE ORACLE_HOME=$ORACLE_BASE/product/8.1.7; export
ORACLE_HOME LD_LIBRARY_PATH=$ORACLE_HOME/lib; export
LD_LIBRARY_PATH TNS_ADMIN=/var/opt/oracle;export
TNS_ADMIN NLS_LANG=american; export
NLS_LANG NLS_DATE_FORMAT='Mon DD YYYY HH24:MI:SS'; export
NLS_DATE_FORMAT RATAB=/var/opt/oracle/oratab;export
ORATAB PATH=$PATH:$ORACLE_HOME:$ORACLE_HOME/bin:/usr/ccs/bin:/bin:/usr/bin:/usr/sbin:/
sbin:/usr/openwin/bin:/opt/bin:.; export
PATH DBALIST="primary.dba@company.com,another.dba@company.com";export
DBALIST

The following script. first calls oracle.profile to set up all the environment  variables. The script. also sends the DBA a warning e-mail if it finds any Oracle  errors:

####################################################################
## ckalertlog.sh                                                  ##
####################################################################
#!/bin/ksh
. /etc/oracle.profile
for SID in `cat $ORACLE_HOME/sidlist`
do
    cd $ORACLE_BASE/admin/$SID/bdump
    if [ -f alert_${SID}.log ]
    then
        mv alert_${SID}.log alert_work.log
        touch alert_${SID}.log
        cat alert_work.log >> alert_${SID}.hist
        grep ORA- alert_work.log > alert.err
    fi
    if [ `cat alert.err|wc -l` -gt 0 ]
    then
        mailx -s "${SID} ORACLE ALERT ERRORS" $DBALIST < alert.err
    fi
    rm -f alert.err
    rm -f alert_work.log
done

Clean Up Old Archived Logs

The following script. cleans up old archive logs if the log file system  reaches 90-percent capacity:

$ df -k | grep arch
Filesystem                kbytes   used     avail    capacity  Mounted on
/dev/vx/dsk/proddg/archive 71123968 30210248 40594232   43%  /u08/archive

#######################################################################
## clean_arch.ksh                                                    ##
#######################################################################
#!/bin/ksh
df -k | grep arch > dfk.result
archive_filesystem=`awk  -F" "  '{ print $6 }' dfk.result`
archive_capacity=`awk  -F" "  '{ print $5 }' dfk.result`

if [[ $archive_capacity > 90% ] ]
then
    echo "Filesystem ${archive_filesystem} is ${archive_capacity} filled"
    # try one of the following option depend on your need
    find $archive_filesystem -type f -mtime +2 -exec rm -r {} \;   
    tar
    rman
fi

Analyze Tables and Indexes (for Better Performance)

Below, I have shown an example on how to pass parameters to a script.:

####################################################################
## analyze_table.sh ##
####################################################################
#!/bin/ksh #
input parameter: 1: password # 2: SID if (($#<1)) then echo "Please enter
'oracle'
user password as the first parameter !" exit 0 fi if (($#<2)) then echo
"Please enter
instance name as the second parameter!" exit 0 fi

To execute the script. with parameters, type:

$ analyze_table.sh manager oradb1

The first part of script. generates a file analyze.sql, which contains the  syntax for analyzing table. The second part of script. analyzes all the  tables:

#####################################################################
## analyze_table.sh ##
#####################################################################
sqlplus -s <oracle/$1@$2
set heading off
set feed off
set pagesize 200
set linesize 100
spool analyze_table.sql
select 'ANALYZE TABLE ' || owner || '.' || segment_name ||
       ' ESTIMATE STATISTICS SAMPLE 10 PERCENT;'
from dba_segments
where segment_type = 'TABLE'
and owner not in ('SYS', 'SYSTEM');
spool off
exit
!
sqlplus -s <oracle/$1@$2
@./analyze_table.sql
exit
!

Here is an example of analyze.sql:

$ cat analyze.sql
ANALYZE TABLE HIRWIN.JANUSAGE_SUMMARY ESTIMATE STATISTICS SAMPLE 10 PERCENT;
ANALYZE TABLE HIRWIN.JANUSER_PROFILE ESTIMATE STATISTICS SAMPLE 10 PERCENT;
ANALYZE TABLE APPSSYS.HIST_SYSTEM_ACTIVITY ESTIMATE STATISTICS SAMPLE 10 PERCENT;
ANALYZE TABLE HTOMEH.QUEST_IM_VERSION ESTIMATE STATISTICS SAMPLE 10 PERCENT;
ANALYZE TABLE JSTENZEL.HIST_SYS_ACT_0615 ESTIMATE STATISTICS SAMPLE 10 PERCENT;
ANALYZE TABLE JSTENZEL.HISTORY_SYSTEM_0614 ESTIMATE STATISTICS SAMPLE 10 PERCENT;
ANALYZE TABLE JSTENZEL.CALC_SUMMARY3 ESTIMATE STATISTICS SAMPLE 10 PERCENT;
ANALYZE TABLE IMON.QUEST_IM_LOCK_TREE ESTIMATE STATISTICS SAMPLE 10 PERCENT;
ANALYZE TABLE APPSSYS.HIST_USAGE_SUMMARY ESTIMATE STATISTICS SAMPLE 10 PERCENT;
ANALYZE TABLE PATROL.P$LOCKCONFLICTTX ESTIMATE STATISTICS SAMPLE 10 PERCENT;

Check Tablespace Usage

This scripts checks for tablespace usage. If tablespace is 10 percent free,  it will send an alert e-mail.

#####################################################################
## ck_tbsp.sh ##
#####################################################################
#!/bin/ksh
sqlplus -s <oracle/$1@$2
set feed off
set linesize 100
set pagesize 200
spool tablespace.alert
SELECT F.TABLESPACE_NAME,
       TO_CHAR ((T.TOTAL_SPACE - F.FREE_SPACE),'999,999') "USED (MB)",
       TO_CHAR (F.FREE_SPACE, '999,999') "FREE (MB)",
       TO_CHAR (T.TOTAL_SPACE, '999,999') "TOTAL (MB)",
       TO_CHAR ((ROUND ((F.FREE_SPACE/T.TOTAL_SPACE)*100)),'999')||' %' PER_FREE
FROM   (
       SELECT       TABLESPACE_NAME,
                    ROUND (SUM (BLOCKS*(SELECT VALUE/1024
                                        FROM V\$PARAMETER
                                        WHERE NAME = 'db_block_size')/1024)
                           ) FREE_SPACE
       FROM DBA_FREE_SPACE
       GROUP BY TABLESPACE_NAME
       ) F,
       (
       SELECT TABLESPACE_NAME,
       ROUND (SUM (BYTES/1048576)) TOTAL_SPACE
       FROM DBA_DATA_FILES
       GROUP BY TABLESPACE_NAME
       ) T
WHERE F.TABLESPACE_NAME = T.TABLESPACE_NAME
AND (ROUND ((F.FREE_SPACE/T.TOTAL_SPACE)*100)) < 10;
spool off
exit
!
if [ `cat tablespace.alert|wc -l` -gt 0 ]
then
          cat tablespace.alert -l tablespace.alert > tablespace.tmp
          mailx -s "TABLESPACE ALERT for ${2}" $DBALIST < tablespace.tmp
fi

An example of the alert mail output is as follows:

TABLESPACE_NAME     USED (MB)   FREE (MB)         TOTAL (MB)            PER_FREE
------------------- --------- ----------- ------------------- ------------------
SYSTEM              2,047             203               2,250                9 %
STBS01                302              25                327                 8 %         
STBS02                241              11                252                 4 %
STBS03                233              19                252                 8 %

Find Out Invalid Database Objects

The following finds out invalid database objects:

#####################################################################         
## invalid_object_alert.sh ##
#####################################################################         
#!/bin/ksh
. /etc/oracle.profile
sqlplus -s <oracle/$1@$2
set          feed off
set heading off
column object_name format a30
spool invalid_object.alert         
SELECT  OWNER, OBJECT_NAME, OBJECT_TYPE, STATUS
FROM    DBA_OBJECTS
WHERE   STATUS = 'INVALID'
ORDER BY OWNER, OBJECT_TYPE, OBJECT_NAME;
spool off         
exit
!
if [ `cat invalid_object.alert|wc -l` -gt 0 ]
then
    mailx -s "INVALID OBJECTS for ${2}" $DBALIST < invalid_object.alert
fi
$ cat invalid_object.alert

OWNER        OBJECT_NAME           OBJECT_TYPE          STATUS
----------------------------------------------------------------------
HTOMEH       DBMS_SHARED_POOL            PACKAGE BODY          INVALID
HTOMEH       X_$KCBFWAIT                 VIEW                  INVALID
IMON         IW_MON                      PACKAGE               INVALID
IMON         IW_MON                      PACKAGE BODY          INVALID
IMON         IW_ARCHIVED_LOG             VIEW                  INVALID
IMON         IW_FILESTAT                 VIEW                  INVALID
IMON         IW_SQL_FULL_TEXT            VIEW                  INVALID
IMON         IW_SYSTEM_EVENT1            VIEW                  INVALID
IMON         IW_SYSTEM_EVENT_CAT         VIEW                  INVALID
LBAILEY      CHECK_TABLESPACE_USAGE      PROCEDURE             INVALID
PATROL       P$AUTO_EXTEND_TBSP          VIEW                  INVALID
SYS          DBMS_CRYPTO_TOOLKIT         PACKAGE               INVALID
SYS          DBMS_CRYPTO_TOOLKIT         PACKAGE BODY          INVALID
SYS          UPGRADE_SYSTEM_TYPES_TO_816 PROCEDURE             INVALID
SYS          AQ$_DEQUEUE_HISTORY_T       TYPE                  INVALID
SYS          HS_CLASS_CAPS               VIEW                  INVALID
SYS          HS_CLASS_DD                 VIEW                  INVALID

Monitor Users and Transactions (Dead Locks, et al)

This script. sends out an alert e-mail if dead lock occurs:

###################################################################
## deadlock_alert.sh ##
###################################################################
#!/bin/ksh
. /etc/oracle.profile
sqlplus -s <oracle/$1@$2
set feed off
set heading off
spool deadlock.alert
SELECT   SID, DECODE(BLOCK, 0, 'NO', 'YES' ) BLOCKER,
              DECODE(REQUEST, 0, 'NO','YES' ) WAITER
FROM     V$LOCK
WHERE    REQUEST > 0 OR BLOCK > 0
ORDER BY block DESC;
spool off
exit
!
if [ `cat deadlock.alert|wc -l` -gt 0 ]
then
    mailx -s "DEADLOCK ALERT for ${2}" $DBALIST < deadlock.alert
fi

Conclusion

0,20,40 7-17 * * 1-5 /dba/scripts/ckinstance.sh > /dev/null 2>&1
0,20,40 7-17 * * 1-5 /dba/scripts/cklsnr.sh > /dev/null 2>&1
0,20,40 7-17 * * 1-5 /dba/scripts/ckalertlog.sh > /dev/null 2>&1
30         * * * 0-6 /dba/scripts/clean_arch.sh > /dev/null 2>&1
*          5 * * 1,3 /dba/scripts/analyze_table.sh > /dev/null 2>&1
*          5 * * 0-6 /dba/scripts/ck_tbsp.sh > /dev/null 2>&1
*          5 * * 0-6 /dba/scripts/invalid_object_alert.sh > /dev/null 2>&1
0,20,40 7-17 * * 1-5 /dba/scripts/deadlock_alert.sh > /dev/null 2>&1

Now my DBA friends, you can have more uninterrupted sleep at night. You may  also have time for more important things such as performance tuning.

References

• Unix in a Nutshell, O'Reilly & Associates, Inc.;
• “Using  Oracle9i Application Server to Build Your Web-Based Database Monitoring Tool,”  Daniel T. Liu; Select Magazine - November 2001 Volume 8, No. 1;
• “Net8:  A Step-by-Step Setup of Oracle Names Server,” Daniel T. Liu; Oracle