What does it mean to run autoconfig on an EBS DB tier?

In a nutshell, it means running adautocfg.sh on the database server.

This is what I did when the listener.ora was missing on one of my EBS servers:

1. Login as the oracle software owner on your server
2. Remove softlink in $TNS_ADMIN called "listener.ora" which points to $TNS_ADMIN/mydb_myserver/listener.ora

cd $TNS_ADMIN
rm listener.ora

3. Create new listener.ora directly under $TNS_ADMIN

cd $TNS_ADMIN
vi listener.ora
-- add the following --
cdb =
  (DESCRIPTION_LIST =
    (DESCRIPTION =
      (ADDRESS = (PROTOCOL = TCP)(HOST = minserver.skead.no)(PORT = 1521))
    )
  )

SID_LIST_cdb =
  (SID_LIST =
    (SID_DESC =
      (ORACLE_HOME= /orasw/oracle/product/19_21)
      (SID_NAME = cdb)
    )
  )


USE_SID_AS_SERVICE_cdb = ON
STARTUP_WAIT_TIME_cdb = 0
CONNECT_TIMEOUT_cdb = 10
TRACE_LEVEL_cdb = ADMIN

LOG_DIRECTORY_cdb = /orasw/oracle/product/19_21/network/admin
LOG_FILE_cdb = cdb
TRACE_DIRECTORY_cdb = /orasw/oracle/product/19_21/network/admin
TRACE_FILE_cdb = cdb
ADMIN_RESTRICTIONS_cdb = ON
SUBSCRIBE_FOR_NODE_DOWN_EVENT_cdb = OFF

# added parameters for bug# 9286476
LOG_STATUS_cdb  =  ON
INBOUND_CONNECT_TIMEOUT_cdb = 60

# ADR is only applicable for 11gDB
DIAG_ADR_ENABLED_cdb  = ON
ADR_BASE_cdb = /orasw/oracle/product/19_21/admin/mydb_myserver

#IFILE=/orasw/oracle/product/19_21/network/admin/mydb_myserver/listener_ifile.ora

4. Run autoconfig

cd $ORACLE_HOME/appsutil/scripts/mydb_myserver/
./adautocfg.sh
Enter the APPS user password:

Result: autoconfig succeeds.

5. Create a new softlink under $TNS_ADMIN

cd $TNS_ADMIN
ln -s mindb_minserver/listener.ora listener.ora