Investigation of the 11g Oracle*Net connection delay when DNS server is unreachable

Oleksandr Denysenko:

“I’d like to introduce new Contributor to this Blog – Robert Oliynichenko.

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

Problem description:

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

Oracle Database Patchset is Out

UPDATE(13-SEP-2010). Patchset was removed from MOS… and then added again…

Just to inform.

Oracle RDBMS PatchSet version is available now!

For now(10-SEP-2010) it’s available only for Linux x86 and Linux x86-64.

Patch number is 10098816.

The size of patchset is about 4.7GB!!!

Quite interesting sentence in readme for this patchset that makes sense for such big size:

Starting with the patch set, Oracle Database patch sets are full installations of the Oracle Database software

Happy patching! 😉


useful links:

NOTE:880782.1 ALERT: Oracle 11g Release 2 (11.2) Support Status and Alerts…

NOTE:1179583.1 List of fixes included in (this document is not available at MOS yet..)

NOTE:1179474.1 Patch Set – Availability and Known Issues (this document is not available at MOS yet..)


Oracle Database 11g Release 2 ( New Features