Monday, February 18, 2019

Webinar: Data Guard Physical Standby Setup in Oracle?

This Webinar helps you to understand the benefits of Oracle Data Guard, available methods and how to setup and common issues.

Date and time: Feb 28th 2019 8:00am-9:00am
Pacific Daylight Time (San Francisco, GMT-07:00)

This Webinar covers following Topics.
· Oracle Data Guard and its Benefits
· Overview of different Data Guard Options
· Difference between RAC vs DG
· Prerequisites
· DataGuard Demonstration
· Common Issues
· Post verification Steps
· References
· Contact Info
· Q&A

To register for this Webinar, please send an email to SatishbabuGunukula@gmail.com.

Note that registrations are limited and first come and first serve basis.
You will receive an email confirmation with meeting session link.

For presentation link Click here

Regards,
Satishbabu Gunukula, Oracle ACE
http://www.oracleracexpert.com

Tuesday, January 15, 2019

ORA-28040: No matching authentication protocol after Oracle 12c upgrade.

After Oracle 12c upgrade users started seeing below errors

ORA-28040: No matching authentication protocol

The main issue is older versions of drivers will not able to connect 12c server. In Oracle 12.1, the default value for the SQLNET.ALLOWED_LOGON_VERSION parameter is set to 11. This means that database clients using pre-11g drivers cannot authenticate to 12.1 database servers unless the SQLNET.ALLOWED_LOGON_VERSION parameter is set to the old default of 8 in $ORACLE_HOME/network/admin/sqlnet.ora

SQLNET.ALLOWED_LOGON_VERSION_CLIENT = 8
SQLNET.ALLOWED_LOGON_VERSION_SERVER = 8

Note that SQLNET.ALLOWED_LOGON_VERSION has been deprecated in 12c.

Even after updating above values users might receive below error.
ORA-01017: invalid username/password: logon denied

In this case users need to add following parameter to sqlnet.ora
SQLNET.AUTHENTICATION_SERVICES = (NONE)

Also few users received ORA-28040 error when creating older version of databases (for ex: 10g) using DBCA

Thanks
Satishbabu Gunukula, Oracle ACE
https://oracleracexpert.com

Wednesday, January 2, 2019

Physical standby redo log must be renamed

When creating standby database using database duplication it completed but received below standby redo error. This error will not stop the replication but user don’t want to see these ORA- errors.

Finished recover at 2019-02-12:15:02:32
ORACLE error from auxiliary database: ORA-19527: physical standby redo log must be renamed
ORA-00312: online log 1 thread 1: '/oracle/redo1/ORCL/ ORCL _1A.rdo'

RMAN-05535: warning: All redo log files were not defined properly.
ORACLE error from auxiliary database: ORA-19527: physical standby redo log must be renamed
ORA-00312: online log 2 thread 1: '/oracle/redo1/ORCL/ORCL _2A.rdo'


Though this didn't stop the data guard replication, the customer wanted to get-rid the message. Starting with v10g, this was an expected behavior to improve the switchover and failover. With v10g, when MRP is started, it will attempt to clear the online log files.

If PRIMARY and STANDBY has the same directory structure then you will see these errors. This is an expected behavior when you don’t set log_file_name_convert parameter. You can get rid-off the error message just setup dummy value

SQL> ALTER SYSTEM SET log_file_name_convert='dummy','dummy';

You should not see ORA messages any more in the alert.log file.

Thanks
Satishbabu Gunukula, Oracle ACE
http://www.oracleracexpert.com

Friday, December 14, 2018

ORA-16664 with ORA-01031 password file issue

Data Guard Broker switchover fails with an ORA-16664 error

DGMGRL> show configuration;
Configuration – ORCL_DG
Protection Mode: MaxPerformance
Databases:
orcl - Primary database
orcl_stdby - Physical standby database
Error: ORA-16664: unable to receive the result from a database

Fast-Start Failover: DISABLED
Configuration Status:
ERROR

Errors from Primary DRC log 2012-01-02 13:46:23.675 NSV2: database actually reached ORCL_STDBY
2012-01-02 13:46:23.677 NSV2: Failed to send message to site ORCL_STDBY. Error code is ORA-16642.
2012-01-02 13:46:23.678 03000000 973032160 DMON: Database ORCL_STDBYreturned ORA-16642

Errors from Standby DRC log 2012-01-03 13:51:24.902 Connection to database ORCL returns ORA-01031.
2012-01-03 13:51:24.903 Please check database ORCL is using a remote password file,
2012-01-03 13:51:24.904 its remote_login_passwordfile is set to SHARED or EXCLUSIVE,
2012-01-03 13:51:24.905 and the SYS password is the same as this database.
2012-01-03 13:51:24.905 NSV0: Failed to connect to remote database ORCL. Error is ORA-01031
2012-01-03 13:51:24.906 NSV0: Failed to send message to site ORCL. Error code is ORA-01031.

Solution : The password file mismatch at primary and standby cuased the issue. Make sure the same password file copied to all nodes

Also verify the connect identifier for for standby database is correct and you are able to tnsping and connect using sqlplus as sysdba.

Refer : Troubleshooting ORA-16191 and ORA-1017/ORA-1031 in Data Guard Log Transport Services or Data Guard Broker (Doc ID 1368170.1)

Regards,
Satishbabu Gunukula, Oracle ACE
http://www.oracleracepxert.com



ORA-16664 error when using ASM filesystem

We have received ORA-16664: unable to receive the result from a database error when enabling the DataGuard broker config

DGMGRL> show configuration verbose;

Configuration - ORCL_DG

Protection Mode: MaxAvailability
Databases:
orcl - Primary database
orlc_stdby - Physical standby database
Error: ORA-16664: unable to receive the result from a database

1. In one of the senario the problem was in the Primary's REDO_TRANSPORT_USER init parameter
The value for this parameter had weird characters and removing helped.

SQL> show parameter redo_transport

NAME TYPE                               VALUE
------------------------------------ --------------------------------
redo_transport_user string          ???DG_USER???


2. The database is running on ASM and running on ASM and Data Guard Broker configuration files were created locally on filesystem.

In this case drop the existing broker configuration from primary and standby local filesystem and creating on broker configuration on ASM helped.

Regards
Satishbabu Gunukula
http://www.oracleracexpert.com