Check for Oracle availability and tablespace capacity

Checking Oracle for availability requires more than just a ping or a 'ps -ef | grep oracle' command. I believe it requires a test accessing Oracle using SQL*Net to verify that the listener is also up and running -- this would be the access that a user would normally use. By actually logging on to the instance, you verify that the instance will accept logins whereas if you only do the above checks, how would you know if logins are not accepted due to archiver log waits?

Along with Oracle being alive and accessible, I also check to make sure it can be used, so I also check for tabalespace capacity.

I have written a few scripts that allows me to check:

1. if all of the Oracle instances are up

2. if any of the extents have reached their maximum limit

3. if any of the tablespaces are running short of freespace

The script can be run from crontab with any interval you feel comfortable with. This script will also page or email the support personnel when any of the above exceptions are met.

If there are any other tests that you would like to do, this script can be easily modified to include them. I use this Monitororcl script as a template and just add functionality at the end.

The query_oracle_instances.sh script that is called from crontab:

#!/bin/ksh 
. /u01/home/oracle/.profile 
/u01/app/oracle/admin/monitororcl 'cat /u01/app/oracle/admin/Get_Oracle_Instance_List'
exit 

The Get_Oracle_Instance_List script:

instance_name1 tnsname1 sys_password_for_this_instance 
instance_name2 tnsname2 sys_password_for_this_instance 
instance_name3 tnsname3 sys_password_for_this_instance 

Here is the MONITORORCL script:

#!/bin/ksh 
#script : Rick Stehno 
# script will monitor to see if Oracle is up 

while [ "$1" != "" ] 
do 
ORACLE_INSTANCE=$1 
ORACLE_TNS=$2 
USR_ID=sys 
USR_PASS=$3 
#       echo "Instance: [$ORACLE_INSTANCE]" 
#       echo "TNS       [$ORACLE_TNS]" 
#       echo "PASS:     [$USR_PASS]" 
LOGFIL=/u01/app/oracle/admin/monitordev1.out 
NOTIFY_LIST=userid1@mobilephone.com,userid2,userid3@pagercompany.com 
# 
# check for critical segments are not reaching maxextents 
# 
sqlplus -s <$LOGFIL 2>/dev/null 
$USR_ID/$USR_PASS@$ORACLE_TNS 
        set pages 0 
        select distinct 'YES' from dba_segments 
        where extents >= (max_extents-5) and segment_name not like '1.%'; 
EOF1 

grep -i '^ORA-' $LOGFIL >/dev/null 
if [ $? -eq 0 ] 
then 
        echo "$0 failed: check $ORACLE_INSTANCE for problems" | /bin/mailx -s "${ORACLE_INSTANCE} : Script failed" $NOTIFY_LIST 

        exit 1 
fi 

MAXEXTENTS_REACHED=`awk '{ print $1 }' $LOGFIL` 
if [ "$MAXEXTENTS_REACHED" = "YES" ] 
then 
        echo "$0 failed: $ORACLE_INSTANCE max extents reached" | /bin/mailx -s "${ORACLE_INSTANCE} : max extents reached" $NOTIFY_LIST

        exit 1 
fi 
# 
# check for unable to allocate next segment 
# 
sqlplus -s <$LOGFIL 2>/dev/null 
$USR_ID/$USR_PASS@$ORACLE_TNS 
        set pages 0 
        select distinct 'YES' from dba_segments ds 
           where next_extent > 
            (select max(bytes) from dba_free_space 
                where tablespace_name = ds.tablespace_name); 
EOF2 
grep -i '^ORA-' $LOGFIL >/dev/null 
if [ $? -eq 0 ] 
then 
        echo "$0 failed: check $ORACLE_INSTANCE for problems" | /bin/mailx -s "${ORACLE_INSTANCE} : Script failed" $NOTIFY_LIST

        exit 1 
fi 

POSSIBLE_NEXTEXT_FAIL=`awk '{print $1 }' $LOGFIL` 
if [ "$POSSIBLE_NEXTEXT_FAIL" = "YES" ] 
then 
    echo "$0 failed: $ORACLE_INSTANCE cannot extend segment" | /bin/mailx -s "${ORACLE_INSTANCE} : max extents reached" $NOTIFY_LIST

    exit 1 
fi 
shift 3 
# echo "shift done" 
done 
echo "Successful completion of $0" `date` 
exit 0 

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