1. SQL Server High Availability Introduction to SQL Server high availability solutions

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3. About Me  10+ years experience with SQL Server  Trainer  Consultant  SQLSatBudapest organizer  Contact:  Email: Janos@iamBerke.comJanos@iamBerke.com  Blog: http://www.iamBerke.comhttp://www.iamBerke.com  Twitter: @JanosBerke

4. Agenda  RPO/RTO or # of 9’s?  Log Shipping  Failover Cluster Instance  Database Mirroring  Availability Groups

5. What won’t be covered?  Designing a SQL Server infrastructure,  Deep technical details,  Monitoring and troubleshooting.

6. RPO/RTO or # of 9’s? 1  # of 9’s:  1,2,3,4,5?  9  ~331,5 day downtime  99  ~3,65 day downtime  99.9  8,76 hours downtime  99.99  52,56 minutes downtime  99.999  5,256 minutes downtime!!!  What is more important  RPO/RTO

7. RPO/RTO or # of 9’s? 2  RPO: Recovery Point Objective  What a customer wants is 0  What a DBA wants is >0  Plan backup strategy (and test!!!!)  RTO: Recovery Time Objective  Define/document restore steps  Define/document case scenarios + script them!  Practice, practice, practice!

8. RPO/RTO or # of 9’s? 3 There are many different HA/BC options in SQL Server like:  Log Shipping  Database Mirroring (Deprecated  )  Failover Cluster Instance (FCI)  Availability Groups (2012 or later version)  Partial Database Availability  Database design matters!  HA/BCP starts here!!!

9. RPO/RTO or # of 9’s? 4  Did I miss something?  AlwaysON This is just a marketing term!

10. Log Shipping 1  What is it good for?  Secondary database availability solution  Reporting workload  Warm stand-by

11. Log Shipping 2 Windows Server SQL Server Instance Storage Primary Database Windows Server SQL Server Instance Storage Secondary Database Windows Server SQL Server Instance Storage Secondary Database

12. Log Shipping 3

13. Log Shipping 4  Pro’s:  Easy to configure  Can be combined with other HA solutions  Separate IO subsystem for each node,  Available in almost all editions! (Web, Std., Ent.)  Con’s:  Manual failover,  Server level objects must be copied manually

14. Failover Cluster Instance 1  What is it good for?  High Availability  The only supported HA solution for distributor database for replication.

15. Failover Cluster Instance 2 Windows Server Failover Clustering (WSFC) Node WSFC Config Instance Network Name SQL Server Instance Instance Network Name Cluster Group Cluster Virtual Network Name SAN Storage + Disk Quorum Active Node Passive Node

16. Failover Cluster Instance 3  Pro’s:  Instance level protection  Std. edition is also supported but only w/ 2 nodes.  Zero client configuration after failover  Con’s:  Can be very expensive,  SPOF  SAN!!!  Failover = crash recovery  Instance stop/start  Difficult to analyze IO issues  SAN switch bandwidth limits  VLF fragmentation can slow down the failover

17. Database Mirroring 1  What is it good for?  Database level high availability  Reporting workload (only Enterprise edition + DB snapshot)  Deprecated!! SQL 2016 will provide AG like DBM in Std.

18. Database Mirroring 2 Windows Server SQL Server Instance Storage Principal Database Windows Server SQL Server Instance Storage Mirror Database Witness

19. Database Mirroring 3

20. Database Mirroring 4  Pro’s:  Easy to configure  Separate IO subsystem for each node,  Available in Standard Edition  Hot stand-by server  Buffer pool is there! Faster failover, no need for a full crash recovery.  “Zero” client configuration after failover  Transparent Client Redirect  FAILOVER PARTNER property in connection string  Automatic page Repair!!!  Con’s:  Standard Edition limits:  Only synchronous mirroring,  1 redo thread.  Server level objects must be copied manually,  Only one secondary server for a single database (but can be combined with Log Shipping)

21. Availability Group 1  What is it good for?  Same as with DBM + some extra features:  Read-only Routing  AG Listener  Can be used for group of databases

22. Availability Group 2 Windows Server Failover Clustering (WSFC) Node WSFC Config SQL Server Instance Instance Network Name SQL Server Instance Instance Network Name SQL Server Instance Instance Network Name SQL Server Instance Instance Network Name SQL Server Instance Instance Network Name Availability Group Availability Group Listener Virtual Network Name Storage WSFC Quorum Witness Remote File Share Primary Replica Secondary Replica

23. Availability Group 3

24. Availability Group 4  Pro’s:  Same as with DBM,  It works with more than one database,  Zero client configuration by using AG Listener,  Read-Only routing.  Con’s:  Server level objects must be copied manually,  Enterprise feature.

25. Availability Group 5  SQL Server 2016  AG will/may be a Standard Edition Feature!  3 synchronous replicas  3 nodes for automatic failover  Limitations in Standard Edition:  1 database / AG  Synchronous replica only  1 redo thread  All these are planned and likely to be changed

26. DEMO Log Shipping, DBM, AAG

27. Say thank you to our Sponsors :

28. Stick around for RAFFLE and the AFTER EVENT!  All our volunteers and organisers do not get paid for organizing this event – If you see them, please:  Give them a hug  Shake their hand  Say thank you  Spread the word  Get involved yourself  Don’t forget to thank the sponsors for their support  Thank the speakers for donating their time, energy and expenses