AlwaysOn Availability Groups How to Setup and Configure using Best Practices

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Agenda AlwaysOn Availability Groups Overview Benefits Requirements Best Practices Troubleshoot Demo: Setup and Configure

AlwaysOn Classification Microsoft’s new catch phrase introduced in 2012 Availability Groups Failover clustered instances (FCI) Database mirroring Log-shipping Replication

Availability Groups Synchronization modes Replicas Synchronous Asynchronous Replicas Supports up to 9 secondary replicas (5 in 2012) Up to 3 replicas can be synchronous 1 Primary replica 2 Secondary replicas Up to 2 replicas can be automatic failover partners

Benefits Redundancy High availability Offload reporting & DW loads Offload backups Copy only full backups No differential Local storage

Automatic Page Repair Errors: 823, 824, and 829 Requests a clean page from replica Asynchronous repair Integrity checks Still run physical_only on primary

Replication Replication Publisher: Supports automatic redirect on failover Subscriber: Supports failover* Transactional replication configured the subscriber’s listener name Merge subscribers require additional manual work Distributor: Role failover not supported

Requirements Windows Cluster SQL Enterprise Edition Recommend Windows 2012 SQL Enterprise Edition Replica Initialization Listener (Optional) Network Name IP Address (Static)

Checklist Items Kerberos Service Broker SSISDB Monitoring All SQL Servers need to use the same service account Service Broker SSISDB Monitoring SQL Agent jobs

Best Practices Disk layout (Please!) Same hardware Same SQL Server features are installed on all replicas Use a Quorum witness Windows cluster Latest patches Perform a planned failover Create a failover document

Best Practices (Cont.) Run performance tests Security policy On primary and secondary replicas Security policy AD policy Local policy Perform volume maintenance tasks (Instant file initialization) Perform a planned failover Create a failover document

Worker Threads Monitor Max Worker Threads When set to 0 (default) SQL calculates the max thread based on CPU count Mirroring process uses at least 2 threads per database Number of CPUs 32-bit computer 64-bit computer <= 4 processors 256 512 8 processors 288 576 16 processors 352 704 32 processors 480 960

Noteworthy Manual failovers of asynchronous databases Snapshot isolation Index page splits Only 1 mirror endpoint per SQL instance Watch out for log backups

Troubleshoot SQL Server error log Windows Event Viewer Cluster log Primary and secondary replica Windows Event Viewer Cluster log Database(s) unavailable – Check the cluster Search Exchange forums

Demo Setup AlwaysOn Backup Restore Listener 172.30.201.150 Group: AG1 Listener: AG1-List Setup and test read routing DMVs Quorum votes AlwaysOn information

Monitoring Perfmon Dashboard 3rd-party monitoring solution Idera SQL Sentry http://sqlmonitor.codeplex.com/ http://msdn.microsoft.com/en-us/library/ff878305.aspx http://technet.microsoft.com/en-us/library/dn135338(v=sql.110).aspx

References AlwaysOn Checklist Overview on AlwaysOn Availability Groups Brentozar.com/go/alwayson Overview on AlwaysOn Availability Groups http://msdn.microsoft.com/en-us/library/hh510230.aspx Replication with AlwaysOn http://msdn.microsoft.com/en-us/library/hh710046.aspx