1.
AlwaysOn
In SQL Server 2012
Fadi Abdulwahab – SharePoint Administrator - 4/2013
http://blogs.msdn.com/b/fabdulwahab/

2.
Terminologies
 High Availability (Planned and Unplanned)
 Disaster Recovery
 Recovery Time Objective (RTO)
 Recovery Point Objective (RPO)
 Budget

3.
Solutions in SQL Server
 Backup and Restore
 Log Shipping
 Replication
 Mirroring
 SQL Cluster
 AlwaysOn
 Mix and Third parties

4.
Backup and Restore
 Can lose data
 Inexpensive Solution for DR
 No HA

5.
Log Shipping
 HA , DR
 No Automatic Failover but automate the process of backup and restore
 Database Level
 Inexpensive solution

6.
Log Shipping

7.
Replication
 Database , Object level
 No automatic failover
 Can use as Load balance
 HA , DR

8.
Replication

9.
Mirroring
 HA , DR
 Automatic failover (need witness server – optional)
 Read-only database for secondary

10.
Mirroring

11.
SQL Cluster
 HA
 Expensive solution ( HD , License ,..)
 Server level
 Include two nodes or more
 Required SAN Storage
 A/P , A/A ,A/A/P,…
 Need DR (Log shipping , Backup and Restore,..)
 No Load Balance ( Use Transactional Replication)

12.
SQL Cluster

13.
AlwaysOn
 New Feature in SQL Server 2012
 Can have 5 replicas (one Primary and four secondary servers)
 HA , DR (enhancement for mirroring) and Read-only access
 Can be sync and async ( No acknowledgement ,minimize the transactions)
 No need for SAN storage (Not like SQL Cluster)
 Can deploy geographical
 Can use Secondary servers for backup and reporting access
 Automatic failover
 Types (Primary (R/W and send trans logs to secondary) and Secondary (R)

14.
AlwaysOn

15.
 Windows Cluster is required
 Interchangeable ( Transactions terminated)
 Failover can be ( Automatic , Manual and forced (possible data lose in
case of async) (by commands)
 Support T-SQL and PowerShell
 Diff Backup not supported for secondary
 Secondary use snapshots to avoid any blocking
 Support page repair
 Client can connect direct , Ava group and Read-only routing

16.
 Read-only settings ( No , Read –intent only , Yes)
 Database should be :
 Not belong to any Ava. Group
 Enable R/W
 Enable Multi User mode
 Full Recovery
 Full backup
 Not used by mirroring

17.
 Automatic Failover (up to 2) (Required Sync)
 Sync (Up to 3)
 Need DNS and Static IP ( can be DHCP)
 Configuration (Full (same path – need backup ) – Join (Already restored) – skip
(restore later
 When SQL user added to Primary the user must created in secondary (except if
use contained databases – New feature in SQL Server 2012)
 Backup Options
 Prefer (run on secondary except if primary not online)
 Secondary only (Not support diff backup)
 Primary only (support diff backup)
 Any replica (based on factors)

18.
Demo
 Prerequisites ( Windows Cluster , 2 instances at least)
 Configuration (Enable , Create Ava. Group and backup)
 Add/Remove databases …
 Add/Remove Replica…
 Suspended and resume…
 Dashboard and DMVs for monitoring

19.
Q&A
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