IBM 5.5 ユーザーズマニュアル

– The secondary server does not repoll the NEs in the network, as this information is 

already present in the database. 

– If the problem is that the primary server's network or database connection has gone 

down, then as soon as the primary server detects this, it shuts itself down. 

An Oracle database lock is used as a semaphore to detect when the primary server goes 
down. The primary server acquires the lock resource and does not release it until the 
primary server goes down. The Oracle server detects that the primary Netcool/Precision 
TN server has gone down and releases the lock. The secondary server blocks and waits until 
the lock is released. When the lock is released, the secondary acquires the lock and becomes 
the primary.

There is also a failsafe in case the network connection goes down or the primary server 
process becomes hung or suspended. The primary updates a table in the database with a 
unique value every n seconds. If the secondary server detects that the time stamp has not 
been updated within n seconds, it stops the primary server's Oracle database session (using 
the Oracle alter system kill session command) and becomes the primary. If this 
occurs, the initial primary shuts itself down as soon as it detects that there is another 
primary server. 

Before you configure Netcool/Precision TN for this failover scenario, ensure that you have 
followed steps 1 through 4 in "Configuring the Netcool/Precision TN servers" on page 54. 
If you are only using Oracle for failover, you do not need to follow any of the other steps in 
that section.

In "Configuring the Netcool/Precision TN servers" on page 54, you will configure the 
Netcool/Precision TN servers to use at least one Oracle user and password. When selecting 
the Oracle users, you must ensure: 

•

The users must either use the DEFAULT Oracle profile or the profile that it uses must 
have its CONNECT_TIME and IDLE_TIME properties set to UNLIMITED. These 
properties must be unlimited so that the database session being used by the instances 
of Netcool/Precision TN will not time out. 

•

The users must have been granted the following privileges: 

grant select on v_$session to username;

grant alter system to username

If a user does not have these privileges, you must set them using an SQL tool such as 
Oracle's SQL*Plus or a third-party SQL tool of your choice. These permissions are 
needed because the secondary server needs the session information from 
v_$session

 and uses the alter system kill session command to stop the 

primary server's database session.