Linux-UNIX: Oracle RAC S-TAP configuration

Oracle RAC (Real Application: Clusters) allows multiple computers to run Oracle RDBMS software simultaneously while accessing a single database, thus providing clustering.

About this task

In a non-RAC Oracle database, a single instance accesses a single database. The database consists of a collection of data files, control files, and redo logs located on disk. The instance comprises the collection of Oracle-related memory and operating system processes that run on a computer system.

In an Oracle RAC environment, two or more computers (each with an Oracle RDBMS instance) concurrently access a single database. This allows an application or user to connect to either computer and have access to a single coordinated set of data.

Procedure

Install S-TAP on all nodes. In case GIM is used, install the GIM client on all nodes, then install the bundle S-TAP on all nodes.
Configure the S-TAP parameters. All of the parameters can be configured through the GIM UI.
- STAP_TAP_IP: public IP configured for the node
- STAP_ALTERNATE_IPS: comma separated list of VIPs (virtual IPs) configured for the node, and the scan listener
  Tip: Use this command to retrieve the value for virtual hostnames to put in STAP_ALTERNATE_IPS:
```
su – grid –c ‘cat $ORACLE_HOME/network/admin/*.ora’|grep –i host
```
  For example:
  [root@racvm121 ~]# su - grid -c 'cat $ORACLE_HOME/network/admin/*.ora'|grep -i host LISTENER_RACVM121=(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=<hostname>)(PORT=1521))(ADDRESS=(PROTOCOL=TCP)(HOST=9.70.148.198)(PORT=1521)(IP=FIRST)))) # line added by Agent
- Configure S-TAP inspection engine parameter: unix_domain_socket_marker=<key>, where <key> value can be found in listener.ora in the IPC protocol definition
  Tip: Command to retrieve value for unix_domain_socket_marker:
```
su – grid –c ‘cat $ORACLE_HOME/network/admin/*.ora’|grep –i KEY
```
  - Example: If the following is a description in the listener.ora
```
LISTENER=(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=IPC)(KEY=ORCL))))
```
    then
```
unix_domain_socket_marker=ORCL
```
  - Example: If there is more than one IPC line in listener.ora, use a common denominator of all the keys:
```
su - grid -c 'cat $ORACLE_HOME/network/admin/*.ora'|grep -i KEY
LISTENER=(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=IPC)(KEY=LISTENER)))) 
LISTENER_SCAN1=(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=IPC)(KEY=LISTENER_SCAN1)))) 
LISTENER_SCAN2=(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=IPC)(KEY=LISTENER_SCAN2)))) 
LISTENER_SCAN3=(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=IPC)(KEY=LISTENER_SCAN3))))  
```
    Guardium uses a string search in the path. In this case LISTENER works for all four and should be used: unix_domain_socket_marker=LISTENER
  - Example: If there is no common denominator, create additional inspection engines with unix_domain_socket_marker corresponding to the specific IPC key(s). For example the guard_tap.ini may look similar to this example in the end:
```
[DB_0]
...
unix_domain_socket_marker=EXTPROC1522
...
[DB_1]
...
unix_domain_socket_marker=LISTENER
```
If the Oracle database is encrypted (ASO/SSL), activate A-TAP on all nodes (active and standby). This example shows an Oracle setup with two users: grid and oracle.
1. Authorize users grid and oracle.
2. Stop the instance on the node that is part of RAC environment using the grid environment by entering the command:
```
srvctl stop instance -db database_name -node node_name -force
```
3. Verify that the instance on the node is stopped by entering the command from the grid environment:
```
srvctl status instance -db database_name -node node_name
```
4. Configure A-TAP by entering the command:
```
/usr/local/guardium/guard_stap/guardctl --db-user=oracle --db-type=oracle --db-instance=oracle --db-home=$ORACLE_HOME --db-version=18.0 store-conf 
```
5. Activate A-TAP by entering the command:
```
/usr/local/guardium/guard_stap/guardctl --db-instance=oracle activate 
```
6. Restart the instance on the node that is part of RAC environment using the grid environment by entring the command:
```
srvctl start instance -db database_name -node node_name 
```
7. Repeat steps 3.a through 3.f on all nodes of the RAC environment.