Mystery of Net Service Topology Model in Oracle Apps/EBS R12
The Net Services Topology Data Model stores the entire topological information about a single Oracle E-Business Suite instance. The data model stores information about each node in the Oracle E-Business Suite instance, which is then used to generate Net Service configuration files such as tnsnames.ora.
The Net Services Topology Data Model stores the following information:
- Database tier: Hostname, Database SID, Database Name, Instance Name, TNS Descriptors
- Application tier: Hostname, FNDFS and FNDSM alias descriptors
There is one more thing, usually causes the confusion i.e. when to de-register the DB or Apps tier from Net Services Topology Model.
Answer is based on, which tier you are speaking of.
for Apps tier - Whenever one deletes the apps tier/node
for DB Tier - Whenever the DB Host Name, Port, SID or DB Name is changed.
-- To de-register the Apps tier -
#perl <AD_TOP>/bin/adgentns.pl contextfile=<CONTEXT_FILE> -removeserver
To de-register DB Tier -
#perl <RDBMS ORACLE_HOME>/appsutil/bin/adgentns.pl contextfile=<CONTEXT_FILE> -removeserver
Sometimes one also needs to purge entire data mode and recreate it. Hence one can purge entire data model as follows.
#perl <AD_TOP>/bin/adgentns.pl contextfile=<CONTEXT_FILE> -removesystem
-- This will clean up the information in fnd_app_servers and fnd_nodes table.
After purging, to repopulate the data model, run AutoConfig on respective tier (DB or Apps), it automatically seeds the data model with relevant data.