Webinar: Oracle Data Guard New Features in Oracle 18c & 19c

This Webinar helps you to understand the benefits of Oracle Data Guard, Standby Database types, protection modes and new features in Oracle 18c and 19c.

Date and time: May 5th 2022 8:00am-9:00am
Pacific Daylight Time (San Francisco, GMT-07:00)

This Webinar covers following Topics.

• Introduction to Oracle Data Guard
• Oracle Data Guard Benefits
• Standby Database types
• Data Guard Protection Modes
• What's new in Oracle 18c
• What's new in Oracle 19c
• 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

Thanks & Regards,
http://www.oracleracexpert.com

DML operations on Active Data Guard standby in Oracle 19c

The DML operations is an Active Data Guard only feature enables DML operations on the standby database to be redirected to the primary to accommodate infrequent writes by reporting applications running against Active Data Guard standby database.

This DML feature introduced in Oracle 19c, this includes DML statements that are part of PL/SQL blocks.

The DML on the standby database will have below steps

• The user executes DML against open standby database.
• DML will be automatically redirects to the primary database.
• The DML will be applied on the primary Datable
• The redo info related change is streamed back to the standby database.
• The application change based redo info completes the DML and data is available for the client.

There are two methods to configure DML Redirection with the help of ADG_REDIRECT_DML parameter.

1. The DML Redirect can be configured at system level, this will apply to all sessions connection to the standby database

Run below command for SYSTEM LEVEL DML Redirection
SQL> ALTER SYSTEM SET ADG_REDIRECT_DML=TRUE SCOPE=BOTH;

2. You can overwrite the system level parameter with alert session command to enable the DML redirect for the current session only.

Run below command to enable SESSION LEVEL DML Redirection 

SQL>ALTER SESSION ENABLE ADG_REDIRECT_DML;

Thanks & Regards

http://oracleracexpert.com

 

Oracle Data Guard New Features in Oracle 18c & 19c

This Webinar helps you to understand the benefits of Oracle Data Guard, Standby Database types, protection modes and new features in Oracle 18c and 19c.

Date and time: Nov 17th 2020 8:00am-9:00am
Pacific Daylight Time (San Francisco, GMT-07:00)

This Webinar covers following Topics.

• Introduction to Oracle Data Guard
• Oracle Data Guard Benefits
• Standby Database types
• Data Guard Protection Modes
• What's new in Oracle 18c
• What's new in Oracle 19c
• 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

Thanks & Regards,
http://www.oracleracexpert.com

ORA-16198: Received timed out error from KSR & LAD:2 network reconnect

I have setup Data Guard and log synchronization happening without any issue but recently I found below errors, which are happening rarely in alert.log file

GWR (PID:13557): ORA-16198: Received timed out error from KSR
LGWR (PID:13557): Attempting LAD:2 network reconnect (16198)
LGWR (PID:13557): LAD:2 network reconnect abandoned
2020-07-13T15:32:25.865034-07:00
Errors in file /oracle/diag/rdbms/orcl/ORCL/trace/orcl_lgwr_13557.trc:
ORA-16198: Timeout incurred on internal channel during remote archival
LGWR (PID:13557): Error 16198 for LNO:2 to 'orcl_stdby'
2020-07-13T15:32:25.865253-07:00
LGWR (PID:13557): LAD:2 is UNSYNCHRONIZED
LGWR (PID:13557): Failed to archive LNO:2 T-1.S-5003, error=16198
LGWR (PID:13557): Error 16198 disconnecting from LAD:2 standby host 'orcl_stdby'

Redo Transport Services failed with ORA-16198 error from primary database standby database using LGWR SYNC mode.

Data Guard Broker log shows below error messages…

Data Guard Broker Status Summary:

  Type                        Name                             Severity  Status

  Configuration               orcl_dg_fsfconf                   Warning  ORA-16608: one or more members have warnings

  Primary Database            orcl                              Success  ORA-0: normal, successful completion

  Physical Standby Database   orcl_stdby                        Warning  ORA-16853: apply lag has exceeded specified threshold

When I very configuration everything looks good and no issues.

DGMGRL for Linux: Release 19.0.0.0.0 - Production on Mon Aug 3 15:19:29 2020
Version 19.5.0.0.0
Copyright (c) 1982, 2019, Oracle and/or its affiliates. All rights reserved.
Welcome to DGMGRL, type "help" for information.
Connected to "ORCL"
Connected as SYSDBA.
DGMGRL> show configuration;
Configuration - orcl_dg_fsfconf
Protection Mode: MaxAvailability
Members:
orcl - Primary database
orcl_stdby - Physical standby database
Fast-Start Failover: Disabled
Configuration Status:
SUCCESS (status updated 34 seconds ago)

If this is happening frequently then it is critical and must take action immediately. In my case it is happening rarely which lean towards time out setting. I see that my current DB has net_timeout as 30.

After research, I have increased the net_timeout to 60 and issue has been resolved.

In case if you are not using Data Guard broker then you can run below command from SQL*Plus

SQL> alter system set log_archive_dest_2 service="orcl_stdby", SYNC AFFIRM delay=0 optional compression=disable max_failure=0 reopen=300 db_unique_name="orcl_stdby" net_timeout=30, valid_for=(online_logfile,all_roles)

In case if you are using DGMGRL command-line interface, then you can run below command

DGMGRL> EDIT DATABASE 'ORCL' SET PROPERTY NetTimeout = 30;

Thanks,
Satishbabu G, Oracle ACE
http://oracleracepxert.com

RMAN-08137: WARNING: archived log not deleted, needed for standby or upstream capture process

 The warning is clear that archive log not deleted and the below are the possible reasons. This post will help you how to manage the archive logs on standby.

RMAN-08137: WARNING: archived log not deleted, needed for standby or upstream capture process

1. The archive log destination on Standby is full
2. Standby destination not accepting any logs due to issues
3. RMAN archive log configuration is set to none/default
CONFIGURE ARCHIVELOG DELETION POLICY TO NONE; # default

First run below command to identify the archive log gap

SELECT ARCH.THREAD# "Thread", ARCH.SEQUENCE# "Last Sequence Received", APPL.SEQUENCE# "Last Sequence Applied", (ARCH.SEQUENCE# - APPL.SEQUENCE#) "Difference" FROM (SELECT THREAD# ,SEQUENCE# FROM V$ARCHIVED_LOG WHERE (THREAD#,FIRST_TIME ) IN (SELECT THREAD#,MAX(FIRST_TIME) FROM V$ARCHIVED_LOG GROUP BY THREAD#)) ARCH, (SELECT THREAD# ,SEQUENCE# FROM V$LOG_HISTORY WHERE (THREAD#,FIRST_TIME ) IN (SELECT THREAD#,MAX(FIRST_TIME) FROM V$LOG_HISTORY GROUP BY THREAD#)) APPL
WHERE ARCH.THREAD# = APPL.THREAD#

Thread Last Sequence Received Last Sequence Applied Difference
---------- ---------------------- --------------------- ----------
1 185685 185669 16

If there is an archive gap then the issue is either standby archive destination is full or standby destination has some issues and not accepting any more logs, based up on the error take appropriate action. As long as you archive logs backed upon on Primary you can proceed deleting the archive logs on standby

In order to manage the archive logs you have 2 options

1. Create a shell script to check applied logs on standby and delete rest on periodic basis
2. Configure FRA for archive logs and set the RMAN archive log deletion policy as per below

SQL> ALTER SYSTEM SET DB_RECOVERY_FILE_DEST_SIZE=800GBG;
SQL> ALTER SYSTEM SET DB_RECOVERY_FILE_DEST='/u01/oracle/FRA';

In case if you are using ASM specify disk group
SQL> ALTER SYSTEM SET DB_RECOVERY_FILE_DEST='+FRA_DISK';

You need to set LOG_ARCHIVE_DEST_1 parameter DB_RECOVERY_FILE_DEST so that archived logfiles will be created at Flash recovery area.
SQL> ALTER SYSTEM SET LOG_ARCHIVE_DEST_1='LOCATION=USE_DB_RECOVERY_FILE_DEST';

Set the RMAN archived log deletion policy as follows.
RMAN> CONFIGURE ARCHIVELOG DELETION POLICY TO APPLIED ON STANDBY;

With above setting the applied archived logs will be deleted automatically when there is a space constraint in flash recovery area.

It’s different for the database where you do the backup, because you want to be sure that the backup is done before an archive log is deleted:
CONFIGURE ARCHIVELOG DELETION POLICY TO APPLIED ON ALL STANDBY BACKED UP 1 TIMES TO DISK;

Regards

Satishababu Gunukula, Oracle ACE

http://www.oracleracexpert.com

Why Oracle DataGuard? New Features in Oracle 18c,19c

This Webinar helps you to understand the benefits of Oracle Data Guard, available methods, protection modes and new features in Oracle 18c and 19c.

Date and time: Jan 3th 2020 8:00am-9:00am
Pacific Daylight Time (San Francisco, GMT-07:00)

This Webinar covers following Topics.

• Introduction to Oracle Data Guard
• Oracle Data Guard Benefits
• Standby Database types
• Data Guard Protection Modes
• What's new in Oracle 18c
• What's new in Oracle 19c
• 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

Data Guard Broker Support for DBMS_ROLLING Upgrades

Data guard broker can remain on during a DBMS_ROLLING upgrade and no need to disable it. In oracle 19c there are many enhancements for Data Guard Broker Support for DBMS_ROLLING Upgrades

• Data Guard broker support is enabled by using the DBMS_ROLLING.BUILD_PLAN procedure
• Before starting a DBMS_ROLLING upgrade the fast-start failover feature must be disabled.
• Role changes are permissible during when rolling upgrade is in progress.
• During rolling upgrade any attempt to enable fast-start failover is rejected.
• Broker support is enabled by default during execution of the DBMS_ROLLING.BUILD_PLAN procedure
• The broker prevents a role change to a standby which is not protecting the current primary. The role changes to the Trailing Group Standby are allowed before the switchover phase. After the switchover phase, role changes are only allowed to the Leading Group Standbys.
• The broker will notifies Global Data Services and Oracle Clusterware as appropriate during the rolling upgrade.
• If the upgrade target is an Oracle RAC database, then the broker automatically reduces the target standby to one instance during the start of the upgrade process and allows the upgrade to proceed. Without the broker, the start of the upgrade is rejected if target has multiple instances running.
• The switchover step during a rolling upgrade should be performed using the DBMS_ROLLING.SWITCHOVER procedure.
• The status of a rolling upgrade being done using the PL/SQL package DBMS_ROLLING and the information is displayed in the broker commands SHOW CONFIGURATION and SHOW DATABASE output.

Please see the output of SHOW CONFIGURATION, where you can see configuration status as ROLLING DATABASE MAINTENANCE IN PROGRESS

Configuration - DRSystem
Protection Mode: MaxPerformance
Members:
North_Sales - Primary database
South_Sales - Transient logical standby database
Fast-Start Failover: DISABLED
Configuration Status:
ROLLING DATABASE MAINTENANCE IN PROGRESS

Please see the output of SHOW Database , where you can see Database status as WARNING.

Database – DRNode1
Role: Physical standby database
Intended State: APPLY-ON
Transport Lag: ***
Apply Lag: ***
Average Apply Rate: ***
Real Time Query: OFF
Instance(s):
South
Database Warning(s):
ORA-16866: database converted to transient logical standby database for rolling
database maintenance
Database Status:
WARNING

Three are specific Requirements DBMS_ROLLING Upgrades on a CDB

• To use DBMS_ROLLING the database compatibility should be set to 12.2 or higher

• Different character sets pluggable databases in a CDB supported for upgrade using DBMS_ROLLING

• The TNS services referenced in the LOG_ARCHIVE_DEST_n parameters must be services that resolve to the root container of the destination database.

• The process assisting DBMS_ROLLING can only execute from the root container.

• While a DBMS_ROLLING upgrade is in progress, if any DDL is executed to start the install, upgrade, or patching of an container then you will get an error.

• When user attempt to start a DBMS_ROLLING upgrade when upgrade to an application container is in progress user will get an error. Before calling DBMS_ROLLING.SWITCHOVER all container databases on the transient logical standby must be plugged in and opened, this helps eliminating logical standby apply engine halt because it cannot apply to a given PDB.

Regards

Satishbabu Gunukula, Oracle ACE

http://www.oracleracexpert.com

One Database Solution for your Enterprise Business – Oracle 12c

Oracle 12c offers new architecture and features, you can manage many databases as ONE by efficient use of resources and reduce IT costs for your Enterprise Business. It also offers one solution for your traditional and cloud environments.

Join the Webinar to learn how this one database solution works for your enterprise business.

Date and time: Mar 16th 2018 8:00am-9:00am
Pacific Daylight Time (San Francisco, GMT-07:00)

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

Oracle GoldenGate 12c New Features - Part2

Hi Everyone,

My articles published in Oracle Experts website media "Allthingsoracle.com" by RedGate

Please see the article using below link.

Oracle Golden Gate 12c New Features – Part 2

In this article I will cover:

• Security
• Coordinated Replicat
• New 32K VARCHAR2 Support
• High Availability (HA) enhancements
• Support for Other Oracle products
• Improvements to feature Functionality

This article will help all Oracle Community to understand Oracle GoldenGate 12c new features and how it helps in continuous availability, disaster tolerance and real-time data integration solutions that enable the management and movement of transactional data across the enterprise.

I hope you will like the article and it will be helpful to you.

Please leave your valuable comments.

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

Webinar: Why Oracle Data Guard and its Benefits

Do you want to know Oracle Data Guard Architecture and its benefits and how you can protect your database from Disaster Recovery? Join the webinar

Date and time: Monday, Aug 15th 2011 8:00am - 9:00am PST

To register for this event send an email to SatishbabuGunukula@gmail.com

Please find the presentation link
http://www.slideshare.net/satishbabugunukula/data-guard-architecture-setup

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