Hi will make post on topics that are related to main direction of this Blog.
So, here we have The First Post about Slow 11.2 SQL*Net connections on AIX“
Oracle 11g utilities like tnsping, lsnrctl or sqlplus on AIX 6.1 hanged for about 2,5 minutes (150 seconds) before connection with alias to any destination when DNS server was unreachable. In the same conditions (host and configuration) 10g utilities connected without delay. Oracle*Net was configured for local naming method only – NAMES.DIRECTORY_PATH=(tnsnames) in the both 10g and 11g Oracle Home. The tnsnames.ora files where identical in the 10g and 11g Oracle Home. The aliases in the tnsnames.ora used host names instead of IP addresses in the connection descriptions; if a host name was substituted by IP address the delay disappeared for this alias. Nevertheless all the host names from tnsnames where described in the /etc/hosts and resolution order was hosts = local, bind in the netsvc.conf (analog of the nsswitch.conf in other UNIXs). This configuration should guarantee local name resolution when DNS server was unreachable. What is the root reason of this delay in 11g Oracle*Net ? Continue reading →