Application Continuity runs during planned maintenance to failover those sessions that do not drain in the predefined drain interval (5 minutes on Autonomous Database ). files. However, there might be limitations in distinguishing separate application services (which is understood by Oracle Net Services) and restoring an instance or a node. sections can be used to address various causes of unplanned downtime. Manual failover allows for a failover process where decisions are user driven using any of the following methods: The broker command-line interface (DGMGRL). Oracle Database offers an integrated suite of high availability solutions that FAN is the first step to hiding outages. Global consistency between the participating databases may be expected and crucial to the application. We decided to investigate and answer three questions: The MAA reference architectures are described in Oracle Database High Availability Overview. While the rebalance operation is in progress, subsequent disk failures may affect disk group availability if the disk contains data that has yet to be remirrored. If Far Sync configuration best practices have been followed, each of these steps will be performed automatically by the database and no manual intervention is necessary. If you are using UCP, then connections are automatically redistributed to the new node. If Oracle RAC instance is not available and ALTERNATE destination is available, then fail over to alternate destination. For more information on how to access the See Section 12.2.2.3, "Best Practices for Performing Manual Failover". For a physical standby database, verify that there are no errors from the managed recovery process and that the recovery has applied the redo from the archived redo log files: For a logical standby database, verify that there are no errors from the logical standby process and that the recovery has applied the redo from the archived redo logs: If you had to change the protection mode of the primary database from maximum protection to either maximum availability or maximum performance because of the standby database outage, then change the primary database protection mode back to maximum protection depending on your business requirements. For example, you can configure the Enterprise Manager Beacon to monitor and detect application response times. protection. In addition, here are instructions for Unsubscribing from Service Notifications. corruptions and recommends the best recovery plan. Oracle ASM automatically rebalances to the remaining disk drives and reestablishes redundancy. Similarly, multiple disk failures in different failure groups in a normal or high-redundancy disk group may cause the disk group to go offline. If the Data Recover Advisor fixes the problem, then there is no need to continue with any further recovery methods. Table 12-6 Flashback Solutions for Different Outages, See Also: Section 12.2.8.2, "Resolving Row and Transaction Inconsistencies", Erroneous transactions affecting one table or a set of tables, See Also: Section 12.2.8.1, "Resolving Table Inconsistencies", Erroneous batch job affecting many tables or an unknown set of tables, Series of database-wide malicious transactions, Enable Flashback Database or use multiple Flashback Table commands, See Also: Section 12.2.8.3, "Resolving Database-Wide Inconsistencies", Single tablespace or a subset of tablespaces, Erroneous transactions affecting a small number of tablespaces, RMAN Tablespace Point-in-Time Recovery (TSPITR), See Also: Section 12.2.8.4, "Resolving One or More Tablespace Inconsistencies". For hangs or situations in which the response time is unacceptable, you can configure Oracle Enterprise Manager or a custom application heartbeat to detect application or response time slowdown and react to these situations. Whether you're looking to report an outage, find out when your power will be restored, or learn about the different types of outages, including why they happen and how best to prepare for them, our Outage Center is a great starting point for all of your outage-related needs! An Oracle ASM instance automatically starts an Oracle ASM rebalance operation to distribute the data on the one or more failed disks to the disks that remain intact in the Oracle ASM disk group. When notified, application reconnects occur transparently to the surviving instances of an Oracle RAC database or to a standby database that has assumed the primary role following a failover. You may have to stop database instances for many reasons, such as upgrading the Oracle software, patching, and replacing hardware. Application Continuity performs this recovery beneath the application so that the outage For outages that require multiple recovery steps, the table includes links to the detailed descriptions in Section 12.2, "Recovering from Unscheduled Outages". If the HR manager decides that the corrective changes suggested by the UNDO_SQL column are correct, then the database administrator can execute the statements individually. If a hardware failure occurs and the failure adversely affects an Oracle RAC database instance, then depending on the configuration, Oracle Clusterware does one the following: Oracle Clusterware automatically moves any services on the failed database instance to another available instance, as configured with DBCA or Enterprise Manager. delays or unnecessary node evictions. Start Redo Apply (physical standby) or SQL Apply (logical standby): Table 12-11 SQL Statements to Start Redo Apply and SQL Apply. Do not use the -force flag with any of these commands. The slave DNS servers are notified of the zone update with a DNS NOTIFY announcement, and the slave DNS servers pull the zone information. Perform these steps after one or more failed disks of one specific failure group have been dropped and must be replaced with new disks: Add the one or more replacement disks to the failed disk group with the following SQL command: A data area disk group failure should occur only when there have been multiple failures. For example, you maintain logical databases in the Orders and Personnel tablespaces. Using a precision tool like Flashback Transaction Query, the database administrator and application developer can precisely diagnose and correct logical problems in the database or application. Table 12-8 summarizes additional processing that may be required when adding a node. Client processes connect to the appropriate instance based on the service they require. This document is intended to provide information to Customers, Implementation partners on unplanned outages that they may experience with their Oracle Retail Cloud Service (s) and what to expect during and after an outage incident. Then, if the production database becomes unavailable because of a planned or an unplanned outage, Oracle Data Guard can switch any standby database to the production role, minimizing the downtime associated with the outage. A service will be made available by multiple database instances to provide a service that is needed. PBCS Outage - Oracle Forums Because the loss affects only the data-area disk group, there is no loss of data. the outage. Flashback Transaction Query is an extension to SQL that enables you to see all changes made by a transaction. The following is an example of a manual DNS failover: Change the DNS to point to the secondary site load balancer: The master (primary) DNS server is updated with the zone information, and the change is announced with the DNS NOTIFY announcement. Shadow lost write protection detects a lost write MAA reference architectures and multitenant architectures are described in an easy to Resolution Method: Provides a short description of how the outage has been resolved. Meanwhile want to check if any other customers are facing the same Outage issue? However, for unplanned downtime the risk of exposure to a single point of failure must be clearly understood. Comments: Provides additional information regarding the problem and resolution. Oracle Cloud Infrastructure Documentation, Overview of Application Thus, the service is provided by other instances in the cluster and processing continues. Such outages carry the RCA indicator next to the outage ID corresponding to a record in the Availability List view. Clients can "subscribe" to node failure events, in this way clients can be notified of instance problems quickly and new connections can be setup (Oracle Clusterware does not setup the new connections, the clients setup the new connections). Following unplanned downtime on the standby database that requires a full or partial data file restoration (such as data or media failure), full fault tolerance is compromised until the standby database is brought back into service. You can flash back the primary database to a point before the tablespace was dropped and then restore a backup of the corresponding data files using SET NEWNAME from the affected tablespace and recover to a time before the tablespace was dropped. With two standby databases a single standby outage does not impact primary availability or zero data loss protection. Utilities can use Oracle Utilities OMS to improve the end-to-end process for unplanned outage events: Prepare grid operators & field personnel for real-life scenarios Improve control room decisions though data analysis and information flow Identify and track outages, their impact, and restoration time in real-time The unplanned outage or service interruption description, including the change request or service request number and a very brief description of the request entered in My Oracle Support Any published Root Cause Analysis (RCA) The number of corrective actions (CA) suggested for each outage type. continuity configuration, and Autonomous Database ensures that your applications are continuously available. For example, issue the following command: If the flashback logs were damaged or lost, it may be necessary to disable and re-enable Flashback Database: However, this is a temporary fix until you create a fast recovery area to replace the failed storage components. In this example, the HR and Sales services are both supported by the remaining Oracle RAC instance. In this case, when one of those multiple instances is lost the clients continue to use the available services across the surviving instances, but there are less resources to do the work. One or more Oracle ASM disks fail, and data area disk group goes offline, Databases accessing the data area disk group shut down, Perform Data Guard failover or local recovery as described in Section 12.2.6.3, "Data Area Disk Group Failure", One or more Oracle ASM disks fail, and the fast recovery area disk group goes offline, Databases accessing the fast recovery area disk group shut down, Perform local recovery or Data Guard failover as described in Section 12.2.6.4, "Fast Recovery Area Disk Group Failure". If fast-start failover is not configured, then perform a manual failover. Thus, with Automatic Block Repair you use an Oracle Active Data Guard standby database for automatic repair of data corruptions detected by the primary database. Oracle provides the following features for high availability for unplanned downtime: Fast-Start Fault Recovery Oracle Restart Oracle Real Application Clusters and Oracle Clusterware Oracle RAC One Node Oracle Data Guard Oracle GoldenGate and Oracle Streams Oracle Flashback Technology Oracle Automatic Storage Management Fast Recovery Area enable shadow lost write protection for a database, a Data Guard standby. Note 2: If this is an Oracle RAC standby database, then there is no affect on primary database availability if you configured the primary database Oracle Net descriptor to use connect-time failover to an available standby instance. Figure 12-3 Network Routes After Site Failover. flashback table, flashback transaction, flashback query flashback When a primary database failure cannot be repaired in time to meet your Recovery Time Objective (RTO) using local backups or Flashback technology, you should perform a failover using Oracle Data Guard. These tools allow the administrator to run manual checks The backup file for the corrupted data file is available locally or can be retrieved from a remote location. You can confirm that you have the correct employee by the fact that Ward's salary was $1875 at 09:00 a.m. Rather than using Ward's name, you can now use the employee number for subsequent investigation. (The database must be mounted to perform a Flashback Database.). PDF Hiding Planned Maintenance and Unplanned Outages from Applications - Oracle For example: This statement shows all of the changes that resulted from this transaction. Whenever a component in a high availability architecture fails, the full protection, or fault tolerance, of the architecture is compromised and possible single points of failure exist until the component is repaired. Figure 12-5 shows Enterprise Manager reporting the status of data area disk group DATA, database Data Guard disk group DBFS_DG, and recovery area disk group RECO. There are no procedural best practices to consider when performing a fast-start failover. ongoing Performance Tuning, High Availability Overview and Best Practices, Oracle Database High Availability physical block corruptions, Does periodic backup validation that helps ensure that prevention and detection at the database level, Oracle Active Data Guard Automatic Block Repair, DB_LOST_WRITE_PROTECT initialization application: Application Continuity hides outages for thin Java-based applications, and Oracle maintenance is sent in-Band. For more information, see "Data Guard Role Transition for Fast Recovery Area Disk Group Failure Local Recovery Steps". All transactions are recorded in the Oracle redo logs that reside in the fast recovery area, so complete media recovery is possible. In some cases, an automatic reinstatement might not be wanted until further diagnostic or recovery work is done. If the primary site fails, then user traffic is directed to the secondary site automatically. If it takes seconds to detect a malicious DML or DLL transaction, then it typically only requires seconds to flash back the appropriate transactions, if properly rehearsed. There are two options for using a standby database to repair block corruption on the primary database: Oracle Active Data Guard and Automatic Block Repair, Extracting Data from a Physical Standby Databases. Applications achieve continuous service when planned maintenance, unplanned outages and load imbalances of the database tier are hidden. Restart Redo Apply with or without real-time apply: Determine the SCN at the primary database. Footnote4Storage failures are prevented by using Oracle ASM with mirroring and its automatic rebalance capability. The HR manager is uncertain how this occurred and wishes to know when the employee's salary was increased. Dbverify and Analyze conduct physical block and Flashback technologies are applicable only to repairing the following human errors: Erroneous or malicious update, delete, or insert transactions, Erroneous or malicious DROP TABLE statements, Erroneous or malicious batch job or wide-spread application errors. categorizes the session state usage as the application issues user calls. 12 Recovering from Unscheduled Outages - docs.oracle.com Reference instructions listed in, Notification Contacts default to email subscription and the contact can set language, time-zone and subscription status using the link at the bottom of an outage notification. This was completed around 9:15 a.m. application code changes, allowing Transparent Application Continuity to be Resolving row and transaction inconsistencies might require a combination of Flashback Query, Flashback Version Query, Flashback Transaction Query, and the compensating SQL statements constructed from undo statements to rectify the problem. Additional Service Administrator Tasks and instructions can be found in the Cloud Portal documentation: Overview of Service Administrator Tasks. As a Service Administrator you will now be able to take advantage of the following new features: Service Administrator: AccessThe initial Service Administrator is the contact who received the original environment access details. Using any FAN-aware pool with Fast Connection Failover configured (such as OCI session pools, Universal Connection Pool, Oracle WebLogic Server Active GridLink for Oracle RAC, or ODP.NET) allows sessions to drain at request boundaries after receipt of the FAN planned DOWN event. On Autonomous Database FAN for planned All that is left to do is to describe to the email toolkit the . To bring an Oracle database to a previous point in time, the traditional method is point-in-time recovery. Type of unavailability. Our interactive Outage Map helps you quickly . detection, Database Resource Management for Resource Limits and
Hadoop Java Io Ioexception Connection Reset By Peer,
Durham County Mugshots,
Todd County Warrant List,
Kelsea Ballerini Tour Setlist 2023,
Articles O