Take a look at the following scenario:
- DML changes are made in the published database.
- Changes get written to the replication tables.
- Changes get replicated to the subscriber.
- Cleanup looks to find entries to remove from the replication tables.
Using SQL Server Management Studio
- Connect to the Publisher in Management Studio, and then expand the server node.
- Expand the Replication folder, and then expand the Local Publications folder.
- Right-click the publication you want to delete, and then click Delete.
SQL Server replication is a technology for copying and distributing data and database objects from one database to another and then synchronizing between databases to maintain consistency and integrity of the data. In most cases, replication is a process of reproducing the data at the desired targets.
Start by right-clicking Replication in Object Explorer, and choosing Publisher Properties: In the Publisher Properties window, select the Publication Databases page: Here you can deselect the database that you're trying to drop. Once you've saved this, you should be able to drop your database.
On publisher server, right click on publication and click on “Properties”. 2. On Publication Properties dialog box, go to “Articles” option from the menu in left hand side and uncheck the checkbox of article you want to remove from replication. 3.
select * from sys. tables where is_replicated = 1, which will give you a list of all tables that are replicated.
MySQL Master-Slave Replication: Starting Replication
- On Master, get the Replication Master Binary Log Coordinates. create a data snapshot using mysqldump. transfer the data on Slave.
- On Slave, Restore the data snapshot. Set the Slave to start replication.
There are two ways to stop replication in the Replication Agent:
- Quiesce the Replication Agent instance to stop replication gracefully. For more information, see “Quiescing the Replication Agent”.
- Suspend the Replication Agent instance to stop replication immediately.
How to stop Log Reader Agent from SQL/Command Line
- Drop subscription at source database (sp_dropsubscription)
- Drop subscription at target database (sp_droppullsubscription)
- Drop publisher (sp_droppublication)
- Remove everything else (sp_replicationdboption)
- Remove databases.
Snapshot replication works slightly differently than transactional replication. A snapshot is bit slower than transactional because on each attempt it moves multiple records, perhaps millions of records, from one end (the publisher) to the other end(the subscriber).
2.Create a replication task
- Go to Snapshot Replication > Replication and click Create.
- Select Remote to replicate snapshots to a remote destination.
- Enter the IP address and credentials of the destination Synology NAS.
- Choose a volume as the replication destination.
Replication works by taking snapshots of the primary. A first replication operation transfers the entire contents of the initial snapshot to the standby. Subsequent replication operations transfer just the delta between the most recent primary snapshot and the last previous snapshot.
Open SSMS, connect to the instance that is running the publication (source) that you want to add article(s) to replication. Verify that the table you want to add exists with a Primary Key. Expand Replication, then Local Publications. Look for the publication you want to add those articles to replication.
Merge replication is a method for copying and distributing data and database objects from one SQL Server database to another followed by synchronizing the databases for consistency. According to the Microsoft SQL Server TechNet, merge replication is implemented by the SQL Server Snapshot Agent and Merge Agent.
Snapshot Replication is an expert of data backup and recovery. Businesses need data protection to prevent data loss from accidental deletion, application crashes, data corruption, and viruses.
As I mentioned at the beginning of the article, when we create a transactional replication, it creates the Log reader agent job, snapshot agent job and cleanup job for expired subscriptions. To view them, expand SQL Server Agent, then expand Jobs. Once the publication is configured, configure the subscribers.
There are four MS SQL Server replication types: snapshot replication, transactional replication, peer-to-peer replication and merge replication.
- Snapshot replication.
- Transactional replication.
- Peer-to-peer replication.
- Merge replication.
- Configuring users for MS SQL Server.
- Importing a database from a backup.
Configure the Publication
- Right-click the Replication folder and click New Publication. The publication database wizard opens, where we need to select the publication database.
- Select Transactional publication as replication type.
- Select the Tables, stored procedures which you want to replicate.
Mirroring refers to keeping copies of database to a geographically different location. Replication referes to creating multiple copies of data objects of a database for distribution efficiency. Replication is done to create a copy of database objects and can be copied to a different database as well.
Snapshots are good for more frequent protection measured in minutes or hours, while backups are used for daily protection. Snapshot retention periods will usually reflect that, with deletion of snapshots occurring after, say, 48 hours, which allows for one or two backups to have taken place in that period.
Types of data replication
- Full table replication.
- Transactional replication.
- Snapshot replication.
- Merge replication.
- Key-based incremental replication.
Depending on the functions supported by your Synology NAS, Snapshot Replication helps you accomplish the following tasks:
- Take and manage snapshots of shared folders and iSCSI LUNs.
- Configure scheduled snapshots and retention settings.
- Create and manage replication tasks for shared folders and iSCSI LUNs.
Peer-to-peer replication provides a scale-out and high-availability solution by maintaining copies of data across multiple server instances, also referred to as nodes. Built on the foundation of transactional replication, peer-to-peer replication propagates transactionally consistent changes in near real-time.
The “snapshot” is a point-in-time copy stored in the same volume used to record the whole data status at the time upon being taken. Snapshots use only a small amount of additional storage space, and exert little impact on system performance.
Modify synchronization
schedules in the Job
Schedule Properties dialog box, which is available from the Jobs folder in SQL Server Management Studio and from the agent details windows in
Replication Monitor.
To specify synchronization schedules
- Run continuously.
- Run on demand only.
- <Define Schedule>
Transactional replication is a feature of Azure SQL Managed Instance and SQL Server that enables you to replicate data from a table in Azure SQL Managed Instance or a SQL Server instance to tables placed on remote databases. This feature allows you to synchronize multiple tables in different databases.
Connect to the Publisher in Management Studio, and then expand the server node. Expand the Replication folder, and then expand the Local Publications folder. Expand the publication that has the subscription you want to reinitialize. Right-click the subscription, and then click Reinitialize.
