Oracle19c-Step by step How To Applying PSU Patch on Oracle Dataguard Environment

Muhammad November 21, 2023

 


Master Oracle Dataguard 19c, Datapump, and patching with our step-by-step guide. Navigate Oracle database nodes like a pro. Learn & upgrade your skills today.

In this article, we will guide you on how to apply a PSU patch on an Oracle Dataguard environment in a step-by-step manner. You will learn important concepts such as Dataguard 19c, Datapump, and patching, which are essential for efficient database management. By following our guide, you will be able to navigate Oracle database nodes like a pro and upgrade your skills.

Key Takeaways:

  • Understanding Dataguard 19c and Datapump
  • Patching basics for Oracle Database
  • Preparing the database for Dataguard
  • Setting up Oracle Dataguard environment
  • Step-by-step guide to applying PSU patch on Dataguard environment

Understanding Dataguard 19c and Datapump

Dataguard 19c is a disaster recovery solution that guarantees high availability in Oracle database environments. It provides real-time data protection and automatic failover during system outages, ensuring that mission-critical applications remain operational. Datapump, on the other hand, is used to migrate data from one database to another, or between different versions of the same database.

Together, Dataguard and Datapump can improve database performance, reduce downtime, and enhance data availability. Datapump can be used to transfer data from the primary database to the standby database, which is a critical component of Dataguard.

Dataguard 19c

Dataguard 19c is designed to provide maximum availability, data protection, and data recovery in a distributed environment. It enables the creation of one or more standby databases that can be located in different physical locations than the primary database. Dataguard ensures that the standby database is synchronized with the primary database, resulting in real-time replication.

The standby database can be used for reporting, backup, or failover purposes, providing an additional layer of redundancy and reducing the risk of data loss. Dataguard can operate in either synchronous or asynchronous mode, depending on the network bandwidth and latency.




Datapump

Datapump is a database utility used to export and import data between databases. It provides a fast and efficient way to transfer data, objects, and metadata across different platforms. Datapump can be used to extract subsets of data, transform it to a different format, and load it into a target database.

Datapump supports several data transfer modes, such as table mode, schema mode, and full mode. It allows the user to specify the object types to be transferred, as well as the import/export parameters.

Patching Basics for Oracle Database

As an Oracle database administrator, patching is a crucial process in maintaining the health and performance of your database system. Patching involves the application of software updates to fix bugs, enhance security, and optimize performance. When done correctly, patching improves the stability and reliability of the database.

There are different types of patches that Oracle releases, including:

  • One-off patches: These patches fix a specific issue or bug.
  • CPU (Critical Patch Update) patches: These patches are released quarterly and address security vulnerabilities.
  • PSU (Patch Set Update) patches: These patches address both bugs and security vulnerabilities. They include all the fixes released in previous CPU patches.

Before installing any patch, it is essential to thoroughly read the release notes and understand the patch's purpose and implications. The release notes provide a detailed description of the patch's contents, including prerequisites, installation instructions, and post-installation instructions.

To ensure a successful patching process, it is crucial to follow the recommended patching procedures and best practices. These practices include:

  1. Backing up the database before patching.
  2. Testing the patch in a non-production environment before applying it to production.
  3. Applying the patch to all nodes in a Real Application Clusters (RAC) environment.
  4. Verifying the patch's success and testing the system after patching.

By following these best practices, you can minimize risks and ensure a smooth patching process for your Oracle database.

Preparing the Database for Dataguard

Prior to setting up Dataguard, it is crucial to prepare the primary server for creating a database with Dataguard. In this section, we will guide you through the necessary steps to configure the primary server for a successful Dataguard setup. By the end of this section, you will have a clear understanding of the specific tasks required to prepare the database for Dataguard.

Creating Standby Redo Log Files

Redo logs are essential for database recoverability. In a Dataguard environment, standby redo logs provide additional information required for recovery. Therefore, creating standby redo log files is essential for high availability. To create standby redo log files, follow these steps:

  1. Identify standby redo log groups and members by specifying the size and destination of each.
  2. Use SQL*Plus or the Data Guard broker to add standby redo log file groups on the primary database.
  3. Open the standby database in read-only mode.
  4. Use SQL*Plus or the Data Guard broker to add standby redo log file groups and members on the standby database.
TipIt is recommended to have at least two standby redo log file groups with a minimum of two members in different disk devices.

Enabling Force Logging

Enabling force logging ensures that all changes made to the database are logged. This is required for Oracle to perform media recovery. To enable force logging, use the following command:

ALTER DATABASE FORCE LOGGING;

Enabling Flashback

Flashback is a feature that allows users to see data as it existed in the past. It is especially useful when a user makes changes to the database that need to be rolled back. To enable flashback, use the following command:

ALTER DATABASE FLASHBACK ON;

Enabling Archivelog

Archiving logs are essential for database recoverability in a Dataguard environment. To enable archivelog mode, use the following command:

ALTER DATABASE ARCHIVELOG;

Setting Required Parameters

To configure the primary database for Dataguard, you must set specific parameters. These parameters define how the database interacts with the standby database and allow Data Guard to synchronize changes between them. The table below shows the required parameters to set:

ParameterDescription
LOG_ARCHIVE_CONFIGSpecifies the location and format of the archived logs on the primary and standby databases.
LOG_ARCHIVE_DEST_nSpecifies the location of archived logs on the primary and standby databases.
DB_UNIQUE_NAMESpecifies the unique name of the primary and standby databases.
FAL_SERVERSpecifies the location and port number of the standby database.
STANDBY_FILE_MANAGEMENTSpecifies how archived redo logs are managed on the standby database.

After setting the required parameters, you must create a standby control file for the standby database. The standby control file is a copy of the primary control file and is used to start the standby database. You can create a standby control file by using the following command:

ALTER DATABASE CREATE STANDBY CONTROLFILE AS ‘file_name’;

Now that you have prepared the primary database for Dataguard, you are ready to proceed with setting up the Dataguard environment. Please continue to Section 5 for the step-by-step guide for setting up an Oracle Dataguard environment.

Setting Up Oracle Dataguard Environment

Setting up an Oracle Dataguard environment involves configuring the primary and standby databases, as well as the necessary network and log file settings. The primary and standby databases should be on different nodes to ensure high availability and disaster recovery. Follow these steps to set up an Oracle Dataguard environment:

  1. Create the primary database with the required configurations, such as enabling archivelog and setting standby redo log files.
  2. Set up the standby database with the same configurations as the primary database. Ensure that the standby database is in sync with the primary database.
  3. Create a network connection between the primary and standby databases. Ensure that the network connection is reliable and secure.
  4. Configure the redo transport service to send redo data from the primary to standby database. This can be done through Oracle Net Services or Oracle Grid Infrastructure.
  5. Configure the log apply service to apply redo data on the standby database. This can be done through the Data Guard Broker or manually through SQL commands.
  6. Configure the fast-start failover (FSFO) service to enable automatic failover in case of a primary database failure. Ensure that FSFO is configured correctly and tested before deploying in production.

Once the Oracle Dataguard environment is set up, it provides a reliable and efficient disaster recovery solution for your Oracle database. The environment ensures continuous availability and minimal downtime for critical applications.

Understanding Patching in a Dataguard Environment

Patching an Oracle database in a Dataguard environment requires careful planning and execution. Even a small misstep can result in data loss or system downtime, impacting the availability and reliability of your database.

Here are some considerations and best practices to keep in mind when patching a database that is part of a Dataguard setup:

1. Patching procedure

Make sure to follow the recommended patching procedure provided by Oracle. This includes preparing the databases, applying the patch, verifying the success, and testing the failover capabilities.

2. Patch compatibility

Ensure that the patch you are applying is compatible with your current Dataguard configuration. Check the Oracle documentation for any known issues or patches that might conflict with your environment.

3. Standby database patching

It is crucial to patch both the primary and standby databases in a Dataguard setup. The standby database should be patched before patching the primary database. This ensures that the latest fixes and updates are available in the standby database before the switchover or failover operation.

4. Dataguard broker

Consider using the Dataguard broker for patching the databases. The Dataguard broker automates many of the manual steps involved in the patching process and provides a simpler and more streamlined approach.

5. Pre-patching checks

Perform pre-patching checks to ensure that the databases are healthy and ready for patching. This includes checking for any pending transactions, ensuring that the disk space is sufficient, checking the database version, and backing up the database.

6. Post-patching verification

Verify the success of the patching process by running the post-patching verification steps provided by Oracle. This includes checking the database version, ensuring that the patch was applied successfully, and testing the failover capabilities.

By following these best practices, you can minimize the risk of errors and ensure a smooth patching process in your Dataguard environment.

Step-by-Step Guide to Applying PSU Patch on Dataguard Environment

Applying a PSU (Patch Set Update) patch on an Oracle Dataguard environment requires careful planning and execution to avoid any disruptions to the availability and reliability of the database system. In this section, we will provide a detailed step-by-step guide on how to apply a PSU patch on an Oracle Dataguard environment with minimal downtime and zero data loss.

Pre-Patching Checks

Before starting the patching process, you must perform some checks to ensure everything is ready for the patch. Here are the steps:

  1. Make sure all databases in the Dataguard environment are running in read-only mode.
  2. Stop the redo apply on the standby database using the following command:
    3. ALTER DATABASE RECOVER MANAGED STANDBY DATABASE CANCEL;
  3. Stop the broker configuration on the primary database:
    4. DGMGRL> DISABLE CONFIGURATION;
  4. Verify that the standby redo logs are active:
    5. SELECT THREAD#,SEQUENCE#,STATUS FROM V$STANDBY_LOG;
  5. Run the pre-patching verification script:
    6. $ORACLE_HOME/OPatch/opatch prereq CheckConflictAgainstOHWithDetail -phBaseDir

Applying the PSU Patch

Once you have completed the pre-patching checks, you can proceed with the actual patching process. Follow these steps:

  1. Stop all the databases in the Dataguard environment using the following command:
    2. SHUTDOWN IMMEDIATE;
  2. Apply the PSU patch on the primary database:
    3. $ORACLE_HOME/OPatch/opatch apply
  3. Apply the PSU patch on the standby database:
    4. $ORACLE_HOME/OPatch/opatch apply
  4. Start the databases in the correct order:
    5. STARTUP NOMOUNT; --for the primary database server
    ALTER DATABASE MOUNT STANDBY DATABASE; --for the standby database server
  5. Start the redo apply on the standby database:
    6. ALTER DATABASE RECOVER MANAGED STANDBY DATABASE USING CURRENT LOGFILE DISCONNECT;
  6. Start the broker configuration on the primary database:
    7. DGMGRL> ENABLE CONFIGURATION;

Post-Patching Verification

After applying the PSU patch on the Dataguard environment, you need to perform some verification steps to ensure everything is working correctly. Here are the steps:

  1. Verify the patch version using the following command:
    2. $ORACLE_HOME/OPatch/opatch lspatches
  2. Verify the databases are in sync using the following query:
    3. SELECT THREAD#,SEQUENCE#,APPLIED FROM V$ARCHIVED_LOG ORDER BY THREAD#,SEQUENCE#;
  3. Test the failover to ensure it works correctly:
    4. DGMGRL> SWITCHOVER TO ;
    DGMGRL> REINSTATE DATABASE ;

By following these steps, you will be able to apply a PSU patch on an Oracle Dataguard environment with minimal downtime and zero data loss, ensuring the availability and reliability of your database system.

Verifying Patch Success and Testing Dataguard Failover

After applying a patch on a Dataguard environment, it is crucial to verify its success and ensure the failover capabilities are working. This section will guide you through the post-patching verification steps and the testing of a failover scenario.

To verify the patch success, you can use the following query to check the current patch level of the database:

SELECT * FROM registry$history WHERE action_time = (SELECT MAX(action_time) FROM registry$history);

This query should return the details of the latest patch applied to the database. Additionally, you can check the alert log and the opatch logs to ensure that the patching process completed without errors.

Now, to test the failover capabilities of the Dataguard setup, you can use the following command to initiate a failover:

ALTER DATABASE RECOVER MANAGED STANDBY DATABASE CANCEL;
ALTER DATABASE COMMIT TO SWITCHOVER TO PHYSICAL STANDBY WITH SESSION SHUTDOWN;
SHUTDOWN IMMEDIATE;
STARTUP MOUNT;
ALTER DATABASE COMMIT TO SWITCHOVER TO PRIMARY WITH SESSION SHUTDOWN;
SHUTDOWN IMMEDIATE;
STARTUP MOUNT;
ALTER DATABASE OPEN;

This command initiates a failover from the primary to the standby database. After executing this command, you can check the alert log and the Dataguard broker logs to ensure that the failover was successful.

Verifying Dataguard Broker Configuration

The Dataguard broker is a management tool that simplifies the administration of a Dataguard setup. You can use the following commands to verify the broker configuration:

  1. DGMGRL> CONNECT /
  2. DGMGRL> SHOW CONFIGURATION;
  3. DGMGRL> SHOW DATABASE verbose 'primary_database_name';
  4. DGMGRL> SHOW DATABASE verbose 'standby_database_name';

The first command connects to the broker. The second command shows the current configuration, and the next two commands show the details of the primary and standby databases. Ensure that the broker configuration is correct and that all databases are in the correct role.

By following these steps, you can ensure that the patching process was successful and the Dataguard failover capabilities are functioning correctly. These steps are crucial to maintaining the availability and reliability of your Dataguard setup.

Monitoring and Managing the Patched Dataguard Environment

After applying the patch on your Dataguard environment, it is essential to monitor and manage the setup to ensure its smooth and efficient functioning. Here are some guidelines to follow:

1. Use Oracle Enterprise Manager

Oracle Enterprise Manager provides an all-in-one solution for monitoring and managing your Dataguard setup. It allows you to view the overall status of your primary and standby databases, identify any potential issues, and troubleshoot them immediately. You can also set up alerts and notifications to proactively manage your environment.

2. Check the Dataguard Broker Configuration

Ensure that the Dataguard broker configuration is correct, and the primary and standby databases are in sync. You can use the following SQL command to check the broker configuration:

DGMGRL> show configuration

Additionally, you can verify the synchronization status by executing the following command:

DGMGRL> show database verbose 'database_name'

3. Monitor the Redo Apply Rate

Check the Redo Apply rate on the standby database to ensure that it is keeping up with the primary database. You can use the following SQL command to monitor the redo apply rate:

SELECT NAME, VALUE FROM V$DATAGUARD_STATS WHERE NAME = 'apply rate';

4. Run Regular Backups

Running regular backups is critical for maintaining the integrity of your Dataguard setup. Ensure that backups are taken on both the primary and standby databases regularly. This will allow you to recover from any potential failures and continue the operations without any data loss.

5. Schedule Periodic Switchover/Failover Tests

Conduct regular failover and switchover tests to ensure that your Dataguard setup is working as expected. It will help you identify any potential issues and fix them before they lead to actual failures. Make sure you schedule the tests during non-business hours to avoid any disruptions.

By following these guidelines, you will be able to monitor and manage your patched Dataguard environment with ease. Regular maintenance and testing will help you ensure the availability and reliability of your database system.

Handling Common Issues and Troubleshooting Tips

When patching an Oracle Dataguard environment, it is essential to be prepared for common issues that may arise during the process. In this section, we will provide troubleshooting tips and techniques to help you overcome these challenges. With these strategies at your disposal, you will be able to maintain the stability and reliability of your patched Dataguard setup.

Common Issues During Patching

"ORA-03113: end-of-file on communication channel"

"ORA-03114: not connected to ORACLE"

"ORA-04031: unable to allocate"

These are some of the most common errors that you might encounter while patching your Dataguard environment. The best way to overcome them is to understand the root cause and apply the appropriate solution.

Troubleshooting Tips

Here are some tips to help you troubleshoot and fix common issues:

  • Check the system requirements: Before applying the patch, make sure that your system meets all the requirements specified in the patch documentation.
  • Check the log files: Review the patch log files to identify the cause of the error. The log files usually provide useful information to help you troubleshoot the problem.
  • Check the database status: Ensure that the database is running and that the listener is up and running.
  • Check the environment variables: Confirm that all environment variables are set correctly and that the ORACLE_HOME and PATH variables are pointing to the correct directories.
  • Check the database parameters: Verify that all database parameters are set correctly, especially those related to memory allocation.

Conclusion

As we wrap up our discussion on how to apply a PSU patch on an Oracle Dataguard environment, it is important to note that mastering these skills is crucial for efficient database management. By following our comprehensive guide, you have gained significant insights into Dataguard 19c, Datapump, and patching in an Oracle database environment.

Your understanding of the Dataguard setup process, necessary preparations, pre-patching checks, and actual patching process has been enhanced. Additionally, you have learned how to verify patch success, test failover capabilities, and monitor and manage a patched Dataguard environment. With these skills, you are better equipped to ensure the stability and reliability of your database system.

We hope this guide has been helpful in upgrading your skills and keeping you ahead in the field of Oracle database administration. Remember to apply best practices and recommended troubleshooting tips when handling common issues that may arise during patching. Keep learning and refining your skills, and stay on top of your game.

FAQ

What is Dataguard 19c?

Dataguard 19c is a feature of Oracle Database that provides high availability, data protection, and disaster recovery for mission-critical databases. It allows for the creation of a standby database that can take over in the event of a failure in the primary database.

What is Datapump?

Datapump is a feature in Oracle Database that provides a fast and efficient mechanism for moving data and metadata between databases. It is commonly used for tasks such as data migration, data synchronization, and data backup and recovery.

Why is patching important for an Oracle database?

Patching an Oracle database is important for several reasons. It ensures that the database is up-to-date with the latest bug fixes, security patches, and performance enhancements. Patching also helps to address any vulnerabilities or issues that may arise over time.

How do I prepare the database for Dataguard?

Before setting up Dataguard, it is necessary to perform certain preparations on the primary server. This includes tasks such as creating standby redo log files, enabling force logging, enabling flashback, enabling archivelog, and setting required parameters. These steps ensure the database is ready for the implementation of Dataguard.

How do I set up an Oracle Dataguard environment?

Setting up an Oracle Dataguard environment involves configuring both the primary and standby databases, as well as adjusting network and log file settings. This allows for communication between the nodes and ensures data protection and availability in the event of a failure.

How does patching work in a Dataguard environment?

Patching an Oracle database in a Dataguard environment requires careful planning and execution. It is important to consider the impact on the standby database and ensure a smooth patching process that maintains the high availability of the environment.

What is a PSU patch and how do I apply it in a Dataguard environment?

PSU stands for Patch Set Update, which is a bundle of critical patch updates released by Oracle to address security vulnerabilities and bug fixes. Applying a PSU patch in a Dataguard environment involves following a step-by-step process that includes preparations, pre-patching checks, and the actual patching process.

How do I verify the success of a patch and test the failover in a Dataguard environment?

After applying a patch in a Dataguard environment, it is crucial to verify its success and test the failover capabilities. This involves performing post-patching verification steps and simulating a failover scenario to ensure the stability and resilience of the environment.

How do I monitor and manage a patched Dataguard environment?

Once the patching process is complete, it is important to actively monitor and manage the patched Dataguard environment. This includes using appropriate tools and techniques to monitor the health and performance of the setup, as well as performing ongoing maintenance activities to ensure its smooth operation.

What are some common issues and troubleshooting tips for patching in a Dataguard environment?

Patching in a Dataguard environment can sometimes lead to common issues. However, with proper troubleshooting techniques, these issues can be efficiently resolved. It is important to follow recommended tips and techniques to maintain the stability and reliability of the patched Dataguard setup.

Muhammad

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