database mirroring

Describes database mirroring as an easy-to-manage alternative to failover clustering.

Returns the name of the originating Publisher for a published database participating in a database mirroring session.

The form of authentication used for database mirroring by a server instance is a property of its database mirroring endpoint.

This counter reports the total number of bytes sent over the network by Service Broker endpoints and Database Mirroring endpoints.

Such time-outs are independent of database mirroring , which has no knowledge of them and is completely unaware of their behavior .

Regardless of the number of mirroring sessions to be supported, the server instance can have only one database mirroring endpoint.

Log shipping can be a supplement to database mirroring and is a favorable alternative to asynchronous database mirroring .

The downside of database mirroring is the need for double the total disk capacity than with a cluster.

At any time during a database mirroring session, the database owner can turn off the witness for a database mirroring session.

If your application requires an entire database to be available at a standby server , use database mirroring rather than replication .

At any point in a database mirroring session, the database owner can disable automatic failover by turning off the witness.

Values specified with the database mirroring options apply to both copies of the database and to the database mirroring session as a whole.

Database mirroring should be able to do a rolling upgrade, but this is not guaranteed, because future changes are unknown.

Database mirroring can be used in conjunction with replication to provide availability for the publication database.

To use database mirroring on a database, the full recovery model is always required.

As long as a database mirroring session remains paused, the transaction log cannot be truncated.

Controls the database properties that define the failover partners of a database mirroring session and their behavior.

The source database must be online, unless the database is a mirror database within a database mirroring session.

At the start of a database mirroring session, the database is in the SYNCHRONIZING state.

We recommend that you configure database mirroring during off - peak hours because configuring mirroring can impact performance .

Client connections to the principal server do not use the database mirroring endpoint.

The database cannot be detached until the database mirroring session is terminated.

This server is either a hot or warm standby server, depending on the configuration and state of the database mirroring session.

Using database snapshots with database mirroring permits you to make the data on the mirror server accessible for reporting.

The name of the failover partner server where database mirroring is configured.

To detect other failures that would otherwise go unnoticed, database mirroring implements its own time-out mechanism.

We recommend that you configure database mirroring during off - peak hours because configuration can affect performance .

Monitoring enables you to verify whether and how well data is flowing in the database mirroring session .

Therefore, you can use only one form of authentication per server instance for database mirroring.

The mirror database in a database mirroring partnership cannot be backed up.

These must be created manually as part of setting up a database mirroring session.

The only active error checking performed for database mirroring occurs for soft error cases.

In its simplest configuration, database mirroring involves only the principal and mirror servers.

Two types of transport security are available for database mirroring: Windows Authentication or certificate-based authentication.

The simple and bulk-logged recovery models do not support database mirroring.

If database mirroring is removed completely, the mirror database is in a recovery state and must be restored in order to become functional.

If you use Transact-SQL to configure database mirroring, you need to understand how to set transaction safety.

By default, a database mirroring session runs in synchronous mode, which depends on having full transaction safety (SAFETY is set to FULL).

When database mirroring is deployed in a production environment, the principal database is the production database.

Check out the database mirroring section below for an interesting alternative to log shipping.

Database mirroring is primarily a software solution to increase database availability by supporting almost instantaneous failover .

Throughout testing, we recommend that you monitor your sessions for network errors that cause database mirroring to fail.

At the start of a database mirroring session, the mirror and principal databases are in this state.

Database mirroring involves two copies of a single database that typically reside on different computers.

Unless you can guarantee that your network is secure, we recommend that you use encryption for database mirroring connections.

At any time, the database owner can manually stop a database mirroring session by removing mirroring from the database.

Total number of database mirroring message fragments received by this connection.

Database Mirroring Monitor always tries to connect to every server instance for which it has stored credentials.

Follow these recommendations for using log shipping or database mirroring with common Notification Services configurations.

In these cases, determine whether the error log contains error message 26023 for the TCP port of the database mirroring endpoint.

If you intend also to use this server for the witness in other database mirroring sessions, assign the role of the endpoint as ALL.

A given server instance can participate in multiple concurrent database mirroring sessions with the same or different partners.

Metadata for database mirroring will not be updated automatically to reflect the new virtual server name.

The sys. Database_mirroring_endpoints catalog view displays information about the database mirroring endpoint of the server instance.

If you connect to a server instance using dbm_monitor permissions, Database Mirroring Monitor informs you that you have limited permissions.

The following example establishes a database mirroring session between partners for an existing mirror database.

Metadata for database mirroring will not be updated automatically to reflect the new computer name.

This endpoint is a special-purpose endpoint used exclusively to receive database mirroring connections from other server instances.

Usually, the Database Mirroring Monitor retrieves status information from the principal and mirror server instances at different times.

For more information about operating with safety off , see Asynchronous Database Mirroring ( High- Performance Mode ) .

In a database mirroring session, the taking over of the principal role by the mirror.

Total number of database mirroring message fragments sent by this connection.

Do not reconfigure an in-use database mirroring endpoint.

If you require only a single destination database, database mirroring is the recommended solution.

Discusses how the database mirroring endpoint functions.

The name of a mirrored database that is registered with the Database Mirroring Monitor.

This topic describes the details of database mirroring sessions that are configured for synchronous operation.

This topic assumes that you are familiar with the fundamental concepts of database mirroring operations.

Log shipping can be a supplement or an alternative to database mirroring.

For information about monitoring database mirroring, see Monitoring Database Mirroring.

Each server instance in a database mirroring session requires a database mirroring endpoint.

Database mirroring runs with either synchronous operation in high-safety mode, or asynchronous operation in high-performance mode.

Database mirroring may be an attractive alternative to clustering.

This catalog view displays the database mirroring metadata for each session in which a server instance is the witness.

We make no recommendations about whether a wide-area network (WAN) is reliable enough for database mirroring in high-safety mode.

For introductions to these technologies, see Overview of Database Mirroring and Understanding Log Shipping.

Optimal database mirroring performance is obtained using asynchronous operation.

For information about using database mirroring with replication, see Replication and Database Mirroring.

If you require multiple standby databases, you can use log shipping alone or as a supplement to database mirroring.

Database mirroring is primarily a software solution for increasing database availability and data redundancy.

This view displays the database mirroring metadata for each mirrored database in a server instance.

In these cases , the time-out delay increases the time between a failure and when database mirroring receive the resulting hard error .

Manual failover can be initiated from either database mirroring partner.

The database mirroring session must be running in high-safety mode and must possess a witness.

Discusses the intricacies of database mirroring sessions, covering a wide range of topics.

For more information about Database Mirroring Monitor, see Database Mirroring Monitor Overview.

Database mirroring is disabled due to a failed redo operation.

The following table describes Log Reader Agent behavior for the various operating modes of database mirroring.

For more information about potential sources of failure, see Possible Failures During Database Mirroring.

In database mirroring, the server instance that monitors the status of the principal and mirror servers.

You can use log shipping and database mirroring to maintain the instance and application databases on a standby server.

If a partner is not listening on its assigned port, modify the database mirroring endpoint to listen on a different port.

All database mirroring sessions on a server instance listen on that port, and all incoming connections for database mirroring use that port.

For more information about operating modes, see Transact-SQL Settings and Database Mirroring Operating Modes.

Although similar in concept, asynchronous database mirroring and log shipping have key differences.

Failures in databases other than the mirrored database are not detectable in a database mirroring session.

The example shows the basic steps for creating a database mirroring session without a witness.

This topic describes the prerequisites and recommendations for setting up database mirroring.

For more information, see "Recommendations for Deploying Database Mirroring, " later in this topic.

For more information about operating with safety on, see Synchronous Database Mirroring (High-Safety Mode).

If the SAFETY option is set to FULL, database mirroring operation is synchronous, after the initial synchronizing phase.

This topic discusses considerations for combining log shipping and database mirroring.

The system administrator must create a separate endpoint in each server instance that is to participate in database mirroring.

Also contains information about configuring alerts on database mirroring events.

Database mirroring provides an alternative or supplement to failover clustering or log shipping.

For database mirroring, authentication and encryption are configured on the endpoint.

Contains performance counters that report information related to Service Broker and database mirroring network activity.

The principal and mirror servers act as partners within a database mirroring session.

Unlike replication, which works at the logical level, database mirroring works at the level of the physical log record.

Database mirroring works with any supported database compatibility level.

If the Configure Database Mirroring Security Wizard welcome screen appears, click Next.

Database Mirroring Monitor is also useful for troubleshooting the cause of reduced data flow .

Contains one row for the database mirroring endpoint of the server instance.

A database mirroring session runs with either synchronous or asynchronous operation.

The database mirroring session adopts the same state as the principal database.

All database mirroring sessions support only one principal server and one mirror server.

Next, follow these steps for each partner that you are configuring for database mirroring.

You cannot change the monitor's refresh rate, but you can refresh the status table from the Database Mirroring History dialog box.

When deciding how to configure database mirroring in a clustered environment, the operating mode you use for mirroring is significant.

This statement removes the database mirroring session and removes mirroring from the database.

Stop the database mirroring session, manually update the database, and then begin a new database mirroring session.

In test environments, it is appropriate to explore all of the operating modes to evaluate how database mirroring performs.

Registered databases are listed below the Database Mirroring Monitor node in the navigation tree.

Entering this statement on the principal server begins the database mirroring session.

For more information, see Possible Failures During Database Mirroring.

For more information about database mirroring, see Database Mirroring.

This dynamic management view returns a row for each database mirroring network connection.

The following example drops database mirroring monitoring on all of the mirrored databases on the server instance.

To automatically maintain a standby database server, you can use log shipping or database mirroring.

If you require more than one destination database, you need to use log shipping, either alone or with database mirroring.

All mirroring connections on a server instance use a single database mirroring endpoint.

This message can occur even if sys. Database_mirroring_endpoints shows the endpoint state as started.

Controls the database properties that define a database mirroring witness.

In a database mirroring session, the copy of the database that is typically fully synchronized with the principal database.

Performance counters for database mirroring.

The database is being mirrored in a database mirroring session.

When the mirror database is ready, and the server instances are configured, the database owner can start database mirroring.

Right-click the database, select Tasks, and then click Launch Database Mirroring Monitor.

Removes the selected database from Database Mirroring Monitor.

Like database mirroring, log shipping operates at the database level.

Contains information about using Database Mirroring Monitor or the dbmmonitor stored procedures to monitor database mirroring or sessions.

For more information about the impact of removing mirroring, see Removing Database Mirroring.

Current role of the local database plays in the database mirroring session.

To pause or resume a database mirroring session use the Database Properties Mirroring page.

Moved the information in this topic from the "Monitoring Database Mirroring" topic.

For information about how to use database mirroring on a replicated database, see Replication and Database Mirroring.

Describes how to set up failover clustering and database mirroring to maximize database availability.

Connect to the server instance for which you want to create a database mirroring endpoint.

If the SAFETY option is set to OFF, database mirroring operation is asynchronous.

Each database mirroring endpoint listens on a unique TCP port number.

RESUME Resumes a suspended database mirroring session.

Introduces the components of database mirroring.

Name of the two copies of the database in the database mirroring session.

Database mirroring is also supported for production deployments.

The database owner can pause and later resume a database mirroring session at any time.

On each partner server, ensure that an endpoint exists for database mirroring.

A server instance can have only one database mirroring endpoint, which has a single port.

Each database mirroring server instance requires a unique listener port that is assigned to the database mirroring endpoint of the instance.

Therefore, if the database mirroring session is paused for too long, the log can fill up.

Stop the database mirroring session by removing mirroring.

For more information, see How to: Allow Database Mirroring Network Access Using Windows Authentication (Transact-SQL).

Specifies the server network address of an instance of SQL Server to act as a failover partner in a new database mirroring session.

You also need to consider whether you're using database mirroring, which requires the full recovery model.

Database mirroring works correctly with the vardecimal storage format.

For more information, see How to: Allow Database Mirroring to Use Certificates for Outbound Connections (Transact-SQL).

The exception is setting database mirroring options.

In the Database Mirroring Monitor dialog box, click Register Mirrored Database to register one or more mirrored database.

This reports audit messages related to database mirroring transport security.

A database mirroring endpoint typically is created in the STARTED state.

For more information, see How to: Allow Database Mirroring to Use Certificates for Inbound Connections (Transact-SQL).

For more information about the effect of removing database mirroring, see Removing Database Mirroring.

Database mirroring can be used between two different failover clusters, but not within a single cluster.

Removes the witness from a database mirroring session.

Database mirroring metadata in catalog views.

Server name of the database mirroring partner.

You can now use database mirroring together with replication.

Contains a row for every witness role that a server plays in a database mirroring partnership.

Contains information about how database mirroring works and how to configure and manage a database mirroring session.

Returns the current update period, that is, the number of minutes between updates of database mirroring status table.

With full safety, the database mirroring session funs synchronously in high-safety mode.

This error, which is severity 16, might indicate that the database mirroring endpoint is not started.

However, you can use database mirroring much like you use log shipping.

In database mirroring, refers to the principal server or the mirror server.

A database mirroring session can have only one witness server, which is optional.

Resume the database mirroring session before the log fills up, or add more log space.

How to: Force Service in a Database Mirroring Session (Transact-SQL).

Before you can start a database mirroring session, you must create the mirror database.

To learn the current size of the redo queue, use the Redo Queue counter in the database mirroring performance object.

Database mirroring has been enabled.

For more information, see Log Shipping How-to Topics or Database Mirroring How-to Topics.

Does replication work in conjunction with log shipping and database mirroring?

Metadata that controls how long rows in the database mirroring status table are preserved.

A new Database Mirroring Monitor has been added.

For more information, see How to: Change Transaction Safety in a Database Mirroring Session (Transact-SQL).

Physical, operating system, or SQL Server problems can cause a failure in a database mirroring session.

A database mirroring endpoint can use any port that is available on the local system when the endpoint is created.

If you use SQL Server Management Studio to start a mirroring session, Database Mirroring Monitor Job is created automatically.

Database mirroring, which is implemented on a per-database basis, keeps a copy of a SQL Server 2005 production database on a standby server.

Database Mirroring Monitor is available only in SQL Server Standard Edition and Enterprise Edition.

Provides support for database mirroring in SQL Server 2005 with new connection string syntax for specifying a failover partner server.

For more information, see "Overview of Database Mirroring" in SQL Server Books Online.

A new database mirroring monitor has been added to SQL Server Management Studio.

Description of the state of the mirror database and of the database mirroring session, can be one of

Specifies an instance of the Database Engine to act as the witness server for a database mirroring session.

State of the witness in the database mirroring session of the database, can be one of

To identify the port currently associated with database mirroring endpoint of a server instance, use the following Transact-SQL statement

Referential integrity, materialized views, snapshot isolation, high availability via database mirroring and

For information about using database mirroring with a failover cluster, see

To configure database mirroring for a publication database

Database Availability: Fast Recovery During Both Crash Recovery and Database Mirroring Failover

Requirements and Considerations for Using Replication with Database Mirroring

Prerequisites for a Database Mirroring Session

Prerequisites and Recommendations for Database Mirroring

Example: Setting Up Database Mirroring Using Windows Authentication (Transact-SQL)

Recommendations for Deploying Database Mirroring

For information about using Notification Services with database mirroring, see

Follow these steps on each server instance that you are configuring for database mirroring

To allow database mirroring network access using Windows Authentication

Database Mirroring Related Dynamic Management Views

Mirroring States Database Mirroring Sessions

Be aware of the following requirements and considerations when using replication with database mirroring

Using Log Shipping or Database Mirroring with Notification Services

To set up database mirroring and log shipping together, the following steps are required

Monitor the state of Database Mirroring

To monitor state changes in a database mirroring session, use the

To manually fail over a database mirroring session

The Impact of Database Mirroring on a Remote Monitoring Instance

Synchronous Database Mirroring High-Safety Mode

Using Certificates for Database Mirroring

Database Mirroring and Database Snapshots

When you register a database, Database Mirroring Monitor caches the following information about the database

To force service in a database mirroring session

For information about database mirroring, see

Role Switching During a Database Mirroring Session

For more information about database mirroring, see

To use the Mirroring page to configure a database mirroring session

Keep the following issues in mind if database mirroring is removed from a published database

Server name of the database mirroring witness

For an introduction to database mirroring, see

How to: Establish a Database Mirroring Session Using Windows Authentication (Transact-SQL)

To configure an endpoint for database mirroring

The following events are available for database mirroring

To establish a database mirroring session

Database Mirroring and Full-Text Catalogs

Database Mirroring and Backup and Restore

To launch the Database Mirroring Monitor

How to: Add a Database Mirroring Witness Using Windows Authentication (Transact-SQL)

For information on using log shipping with database mirroring, see

To create a database for database mirroring

To set up database mirroring