OID : Deleting OID/OPMN instances

One can face weird issues due to OID Instances not being deleted the right way. Simply deleting them from the file system or from OID might not be enough as there are entries that stay on the ODS Schema of the Database.
This can cause unforseen issues like delay in OID restarts (ldapbind fails for few mins even though instance shows up as ALIVE) or weird issues like referential integrity working intermittenly in OID/OIM.

It is highly recommended to remove an Oracle Internet Directory component by using opmnctl deletecomponent. This also unregisters the component with the WebLogic server.

Syntax :

$ORACLE_INSTANCE/bin/opmnctl deletecomponent
  -adminHost webLogicHostName
  -adminPort webLogicPort
  -adminUsername weblogicAdminUsername
  -adminPasswordFile text_file_containing_admin_password
  -componentType OID
  -componentName componentName

Sample for removing an instance named oid4
export ORACLE_INSTANCE=/u01/app/oracle/admin/config/oid_inst_3/
$ORACLE_INSTANCE/bin/opmnctl deletecomponent \
  -adminHost <wl_server_Name> \
  -adminPort 7001 \
  -adminUsername weblogic \
  -adminPasswordFile adminpass.txt \
  -componentType OID \
  -componentName oid4

Reference - https://docs.oracle.com/cd/E16764_01/oid.1111/e10029/oid_server_instances.htm#BABDJABF