SYED SAJID WASIM SQL SERVER ALWAYS ON Step by Step

SYED SAJID WASIM Manager ADC, DHAKABANK Limited Focused on database and development technologies MCT, MCSE, MCTS on Data Platform 18 Years IT Industry Experience Working with SQL Server since version 6.5 www.Linkedin.com/in/SajidWasim

What is SQL Server AlwaysOn? Introduced in SQL Server 2012 Requires SQL Server Standard/Enterprise Edition SQL Server AlwaysOn describes two distinct SQL Server High Availability features: AlwaysOn Availability Groups AlwaysOn Failover Cluster Instance

Why SQL Server AlwaysOn? Feature Database Mirroring AlwaysOn AG Maximum number of secondary databases 1 Mirror 8 Secondaries Requires Windows Clustering No Yes, however the SQL Servers can be stand-alone Automatic failover Yes, requires witness server and high-safety mode Yes, one HA or DR Choose one Each secondary independently configurable Groups of databases No, each database is configured separately Multiple databases can be grouped to failover together Can be used for reporting Only against a database snapshot of the  mirror Yes Offload backups Connection to active database Requires special connection string for failover Redirection handled by Windows Clustering with a virtual name. Special connection string not required Connection string to mirror or secondary database N/A Can be configured with an Application Intent connection string to automatically redirect or can use traditional connection string with server name. Why SQL Server AlwaysOn?

FEATURES Grouping Databases into Failover Groups Integration with Windows Server Failover Clustering (WSFC) Uses WSFC quorum models Uses Cluster Client Access Point Important features Database Health causing failovers Support for Distributed Transaction Coordinator Synchronous replicas Optimized log transport Load balancing

Business Intelligence High Availability features for SQL Server 2016 Licenses: Feature Name Enterprise Business Intelligence Standard Web Express Server Core support Yes Log Shipping   Database mirroring Yes (Safety Full Only) Witness only Backup compression Alwayson Failover Cluster Instances Yes (Node support: Operating system maximum Yes (Node support: 2) AlwaysOn Availability Groups Yes (up to 8 secondary replicas, including 2 synchronous secondary replicas) …

AlwaysOn Requirements System Setup Use Server Manager to install the Failover Clustering feature on all nodes. Use the Failover Cluster Management tool to create a new Windows failover cluster. Install a new standalone instance of SQL Server on each cluster node.

AlwaysOn Requirements Database Setup Availability groups must be created with user databases. Systems databases can't be used. Databases must be read-write. Read-only databases aren't supported. Databases must be multiuser databases. Databases can't use the AUTO_CLOSE feature. Databases must use the full recovery model, and there must be a full backup of them. A given database can only be in a single availability group, and that database can't be configured to use database mirroring.

Steps Configuring AlwaysOn Availability Groups Install Windows Cluster Install a Standalone SQL Server 2012 Use the domain account for the SQL service account Open Port 1433 and 5022 or disable the Windows Firewall Create a sample database Set recovery model to Full Back up this sample database Enable the AlwaysOn feature on both instances using SQL Server Configuration Manager Create an Availability Group using the Availability Group Wizard

DEMO

Resources Always On Overview http://msdn.microsoft.com/en-us/library/ms189134.aspx http://www.tech-coffee.net/alwayson-availability-group-introduction https://channel9.msdn.com/posts/SQL11UPD01-REC-07 Understanding Quorum in a Failover Cluster http://blogs.msdn.com/b/clustering/archive/2011/05/27/10169261.aspx Understanding File Share Witness Placement http://blogs.technet.com/b/askpfeplat/archive/2012/06/27/clustering-what-exactly-is-a-file-share-witness-and-when-should-i-use-one.aspx Configuring Availability Groups http://blogs.technet.com/b/scvmm/archive/2012/10/24/how-to-configure-sql-2012-alwayson-availability-groups-in-system-center-2012-virtual-machine-manager-service-pack-1.aspx http://www.brentozar.com/archive/2011/07/how-set-up-sql-server-denali-availability-groups/ What’s New in Failover Clustering in Windows Server 2012 R2 http://technet.microsoft.com/en-us/library/dn265972.aspx

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