Luis Vargas | Senior Program ManagerDarmadi Komo | Senior Product Marketing Manager

SQL Server on Windows Azure VMsHigh Availability & Disaster Recovery

Meet Luis Vargas | @lvargas• Senior Program Manager in SQL Server

– SQL Server IaaS / hybrid scenarios– AlwaysOn (High Availability)

• Over 10 years of industry experience– Microsoft: PM– Financial Services: Dev

• PhD in Database Systems– Cambridge University

Windows Azure VMs Overview

Windows Azure VMsOverview

• VMs hosted on Windows Azure infrastructure (“IaaS”)• From Microsoft images or your own images (VHDs)• Fast provisioning (10 minutes)

• Pay per use• VM: By minute

• Cost depends on size and licensing (e.g. SQL)• Network: only incoming (not outgoing)• Storage: only used (not allocated)

• Elasticity• 1 core / 2GB RAM / 1TB 8 cores / 56GB RAM / 16TB

• You manage the VM• Security, patching, monitoring, etc

• Every VM disk is a BLOB in Azure Storage

• 3 sync local copies• No data loss• highly available (transparent to VM)

• 3 more async remote copies (if geo-replication enabled)• For disaster recovery (manually managed by Microsoft)

Windows Azure VMsStorage

MICROSOFT CONFIDENTIAL – INTERNAL ONLY

Physical Machines

Power UnitRack Switch

Availability Set

VM1VM1 VM2 VM2

Load-Balanced Set

Load Balanc

er

Windows Azure VMsGeneral approach for high availability

SQL Server on Windows Azure VMsHA & DR support• HA

• SLA: No data loss• If VM becomes unavailable, restart in another host• SLA: 1 of 2 VMs in Availability Set:

• 99.95% (<22 min downtime p/month)• Includes

• Planned downtime due to (monthly) host OS servicing• Unplanned downtime due to physical failures

• Doesn’t include servicing of guest OS

• DR• <30 min (No SLA)• Azure Ops recovers VM (No SLA)

Windows Azure VMsExternal Connectivity

• Over the Internet• Public endpoints

• Over a site-to-site tunnel• Extend on-premise network to Azure

• Can join Azure VMs to on-premise domain• Secure tunnel• VPN Device / Windows Server RRAS

SQL Server on Windows Azure VMs• Many SQL versions supported

• SQL 2014 CTP1, SQL 2012 SP1, SQL 2008 R2

• (Almost) 100% compatibility• No SQL Failover Clusters (yet..)

• You manage SQL Server• Security, Backups, HA, DR, etc

SQL Server HA/DR Scenarios withWindows Azure VMs

SQL Server HA/DR Scenarios• HA within Azure

• Availability of SQL Server in Azure VM • Protect from issues impacting SQL Server or VM• Use another SQL Server VM in same Azure DC

• DR between On-Premise and Azure• Availability of on-premise SQL Server (physical or

virtual)• Protect from issues impacting on-premise data center• Use a SQL Server VM in Azure

SQL Server HAwithin Windows Azure

Why?• Azure’s failure detection for VM (not SQL

Server)• SQL Server service could be down or hung• Servicing of guest OS causes downtime• Servicing of SQL Server causes downtime

• Azure’s service healing involves restarting VM in different host

• ~12 min downtime each time

• Azure’s upgrade involves servicing host OS and restarting VM in the host

• ~15 min downtime each time

What to do?Configure a SQL Server HA technology

Windows Azure

S PP S

VM VM

• Failure detection for SQL Server• Failover takes ~15s

VM

Witness

What to do?Supported SQL Server HA technologies

Technology SQL Server Version

Zero Data Loss

Scope # Replicas

AutomaticFailover

ReadableSecondaries

Availability Groups

SQL Server 2012SQL Server 2014

Yes(Sync Mode)

DB(s) 4

9

Yes(w/ additional cluster member)

Yes

Database Mirroring

SQL Server 2008 R2SQL Server 2012

Yes (High Safety Mode)

DB 1 Yes(w/ Witness)

Limited(database snapshots)

Availability Groups• Provide many other capabilities:

• Flexible Failover Policy• Automatic Page Repair• Backups on Secondaries• Improved Manageability• FileStream & FileTable support

• But remember they need:• Windows Cluster

• No shared storage• Same Windows Domain

• Needs an Active Directory Domain Controller

Before starting any configuration..Ensure the VMs are hosted appropriately

• Same Affinity Group• Same Azure cluster• Reduces log synchronization latency

• Same Availability Set• Different Fault Domain (rack) and Upgrade Domain• Ensures that a rack failure or Azure’s upgrade impacts

at most one replica

• Same VNet• Ensures that VM IPs don’t change after Azure’s service

healing (avoids DNS update time: ~12 min)• Requirement for Active Directory

A sample configuration

SQL Server DRbetween On-Premiseand Windows Azure

Why?• An event can cause on-prem SQL Server to

become unavailable• Temporarily (e.g. gateway failure)• Permanently (e.g. flooding)

• A disaster recovery site is expensive• Site rent + maintenance• Hardware• Ops

What to do?Configure a SQL Server DR technology

• Deploy one or more secondary replicas for on-premise SQL Server

• Replicas continuously synchronize• Replica (Azure) storage guarantees no data loss

• At best region• West US, East US, East Asia, Southeast Asia, North

Europe, West Europe• Latency / political considerations

• Low TCO• VM and storage• Free incoming traffic

What to do?Configure a SQL Server DR technology

Deployments may be invertedSometimes people want to keep a replica on-premise

What to do?Supported SQL Server DR technologies

Technology

SQL Server Version

Zero Data Loss

Scope

# Secondaries

AutomaticFailover

ReadableSecondaries

Availability Groups

SQL Server 2012SQL Server 2014

No(Async Mode)

DB(s) 4 No Yes

Database Mirroring

SQL Server 2008 R2SQL Server 2012

No(High Performance Mode)

DB 1 No Limited(database snapshots)

LogShipping

SQL Server 2008 R2SQL Server 2012

No DB N No Limited(standby state)

- Async Mode (High Performance) avoids impacting primary performance- Async Mode only supports Force Failover to make potential data loss a

conscious decision

Availability Groups• Provide additional benefits:

• Integrated HA/DR• Offload Read workloads to Azure

• Connect reporting/BI apps• Migrate apps and run against local secondaries

• Offload Backups to Azure• A solution for policy compliance

• Remember it requires:• Same Windows Cluster • Same Windows Domain

What to do?• Configure site-to-site tunnel

• Using VPN device or Windows Server RAS

• Join VM to the Domain

• Add VM SQL Server as replica of Availability Group

Sample Deployment

SQL Server DRbetween On-Premise and Windows AzureDemo

In SQL 14 CTP2..

• Many customers can’t afford a DR site• Site rent + maintenance, hardware, Ops

• SQL Server 2012: Started supporting replicas on Windows Azure VMs this year

• Offload read workloads • Offload backups (policy compliance)• Disaster recovery

• At best region• West US, East US, East Asia, Southeast Asia, North

Europe, West Europe• Latency / political considerations

Availability GroupsAdd Azure Replica Wizard

Sync LogSynchronization

Async Log Synchronization

Availability GroupsAdd Azure Replica Wizard

• Low TCO• VM and storage• Free ingress traffic

• SQL Server 2014: “Add Replica Wizard” supports Windows Azure

• E2E: From provisioning VM to starting log synchronization

• Validates environment• Handles failures

Availability GroupsAdd Azure Replica Wizard

Add Azure Replica Wizard

Demo

ResourcesSQL Server HA/DR on IaaS• Tutorials and scripts

• http://msdn.microsoft.com/en-us/library/jj870962.aspx

IaaS• Create Virtual Network in Azure

• https://www.windowsazure.com/en-us/manage/services/networking/create-a-virtual-network/

• Create Virtual Network from on-premise to Azure• https://www.windowsazure.com/en-us/manage/services/n

etworking/cross-premises-connectivity/• Set up Active Directory Domain Controller

• http://www.windowsazure.com/en-us/manage/services/networking/active-directory-forest/

Download SQL Server 2014 CTP2 today! Give us feedback at Microsoft Connect!

© 2013 Microsoft Corporation. All rights reserved. Microsoft, Windows, Windows Vista and other product names are or may be registered trademarks and/or trademarks in the U.S. and/or other countries.The information herein is for informational purposes only and represents the current view of Microsoft Corporation as of the date of this presentation. Because Microsoft must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information provided after the date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.

Luis.Vargas@Microsoft.com