Schizophrenic High Availability with SQL and Windows 2016

Mark Broadbent

Principal Consultant

SQLCloud

SQLCLOUD.CO.UK

Schizophrenic High Availability

with SQL

and

Windows

2016

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About

Mark Broadbent.“30 billion times more intelligent than a live mattress”Microsoft Certified Master/ Certified Solutions Master: SQL Server

Microsoft Data Platform MVP

Principal at SQLCloud

Email: [email protected]

Twitter: retracement

Blog: http://tenbulls.co.uk

Event Lead to the UK’s first ever SQLSaturday (Cambridge)

– now also SharePoint Saturday

Event #4 on 8/ 9/ 10th Sept 2016 (pre-cons & Community day)

http://sqlcambs.org.uk

http://tenbulls.co.uk/

http://sqlcambs.org.uk/


Agenda

Virtualization

3

ClusterStorage

2

Import generic

Import generic

Import generic

The Road to Schizophrenic HA

1

The best part of the presentation… Gin-O-Clock

5New and Cool HA

features

4


In the beginning…


Schizophrenic HADR

Serial Attached SCSIFibre Channel iSCSI

Import generic

Import generic

Import generic

SMB 3.0 Fileshare

Serial ATA is not supportedfor cluster shared storage

?

??

?

?

?


SQL Failover Clustering

• Clustered Application/ resource, active on one node at a time

• Requires Windows Cluster and a Windows Cluster which requires single Windows Domain

• Storage visibility

• Support multi-site/subnets but with considerations• Quorum• Storage replication• Subnet IP or dependency• WAN reliability

Cluster Shared StorageSubnet 1 Subnet 2


Availability Groups

• SQL now standalone but still requires Windows Cluster (quorum and HA components) -remember the single domain

• Read-only routing of read-only queries directed only to first available replica

• Support multi-site/subnets but with considerations• Quorum• Storage replication• Subnet IP or dependency• WAN reliability, Latency (log stream inefficiency)

Primary Replica

Subnet 1 Subnet 2

Availability Group Resource

Currently no MSDTC and cross database transaction

support in AG …but….

Secondary Replica

ReplicaDatabases

Listener

async

sync

Availability group secondariesmay be readable replicas


Cluster Shared Volumes for SQL FCIs

• Supported by SQL Server 2014 on Windows 2012 R2 (introduced in Windows 2012)

• Consolidation of multiple SQL instances

• Large FCI cluster deployments could run out of drive letters

• Consolidating multiple SQL instances on single LUN makes the storage utilization more efficient

• Fast failover – no dismount and mount during failover!

• Easier to configure and more resilient• Zero downtime chkdsk

• Resilience from network failures (CSV can reroute traffic over the network using SMB 3.0 allowing the SQL instance to remain operational

• Good for Hyper-V Cluster Storage but consider performance hit from redirected IO


SMB 3.0 File Shares

• SMB 3.0 supported by Hyper-V Windows 2012/R2 & SQL 2012/2014

• Not assigned to the Cluster

• Cannot be added to Cluster Shared Volumes

• Very easy to configure and consume

• Low cost connectivity

• No Filestream support Failover Cluster

File Server


Scale-Out File Server Cluster

Failover Cluster

HDD3TB

HDD3TB

HDD3TB

HDD3TB

HDD3TB

HDD3TB

HDD3TB

HDD3TB

HDD3TB

HDD3TB

HDD3TB

HDD3TB

SSD600GB

HDD3TB

HDD3TB

HDD3TB

RDMA Cards

HBA Storage Adapters

JBOD Array

SMB Multichannel

SMB Direct RDMA

Continuous Availability File Share

Cluster Shared

Volumes

MultipathIO

Storage Spaces

FailoverClustering

Scale-Out File Server

Infiniband Switches


Microsoft Storage Spaces Direct

• Utilize high speed NVMe local storage or SATA

• Eliminate need for shared SAS Fabric

• Perfect for Hyper-V• Disaggregated deployment (needs SoFS) or Hyper-converged stack

• Create Storage tiers


Hyper-V scalability limits

Guest

• 64 vCPUs

• 1 TB Memory

• 64 TB VHDX virtual disks

• 4 Virtual Fibre Channel Adapters

• 12 Virtual NICs

Host

• 320 Logical processors

• 1024 virtual machines per host

• 4 TB Memory


Hyper-V Benefits

• Replication

• Exports

• Live Storage Migration

• Live Migration

• Quick Migration

• Checkpoints (snapshots)

• QoS on disks, Bandwidth, CPU etc

• Fast Boot

• Azure portability *1

*1 Generation 2 Machines not compatible (although ASR can support)


Ph

ysical Infrastru

cture

Gu

est Clu

ster

Hypervisors

Guests

Hyper-V Cluster

SQL Server Cluster

Storage Fabric

Guest Clustering on a Hyper-V Cluster

• Clustered Virtual Machines on Hyper-V cluster

• SQL Clustered Instance can failover to each VM in the Guest Cluster

• Guest VM benefits from “Clustered Live Migration” in Hyper-V

HDD3TB

HDD3TB

HDD3TB

HDD3TB

HDD3TB

HDD3TB

HDD3TB

HDD3TB

HDD3TB

HDD3TB

HDD3TB

HDD3TB

SSD600GB

HDD3TB

HDD3TB

HDD3TB


Stretch Database

EXEC sp_configure 'remote data archive', 1;GORECONFIGURE

Single trickle thread (for now)Automatically move cold table data to azure (row predicate should be possible)Transparently query across table & Azure

orders

id status

1 0

2 2

3 1

4 0

Trickle thread


SQL XI

• Data/ log files in Azure

• Bypass Azure limit of 16 VM disks

• Performance benefits to Virtual disks• Bypasses Virtual Disk driver and passes through virtual network driver

• Cloud Portability


DEMOHyper-V Live Migration, Stretch DB and SQLXI


Azure Cloud Witness

• Windows 2016 Quorum Configuration• Use Storage account name

• Primary or secondary key

• (optional) specify service endpoint

• Azure Witness uses HTTPS REST so https port must be open on all cluster nodes

• If regenerating access key, first rotate to secondary/ primary

• Set storage account to “Locally Redundant” for Replication Type

Azure blob storage

Azure blob storage

msft-cloud-witness


Direct Seeding

• Based on Azure Database seeding

• Group seeding per replica (manual seeding possible)

server1

server2

server3

File Server

TCP 5022 TCP 5022Replica backup stream

Backup stream

Restore stream

Availability Group


Read only routing - load balancing

• Read only routing list configured on primary role

• Applications must• Connect through Listener

• Connection string must specify Application Intent=ReadOnly

• Parentheses identifies load balanced set

READ_ONLY_ROUTING_LIST=((‘server2’,‘server3’,‘server4’),‘server5’,‘server6’)

server1 server2 server3 server4 server5 server6


Basic Availability Groups

• Standard Edition (or Enterprise)

• 2 replicas (configured on setup)• No upgrade to advanced AG

• Cannot add or remove replicas

• No support for replicas prior to 2016

• Sync or Asyc

• No offloaded backups and no readable replica (snapshot possible)

• 1 Availability Group with 1 Database replica


Domain-Independent Availability Groups

• Nodes must run Windows 2016

• Needs Failover Clustering Feature and DNS

• Intra-cluster communication via certificates

• Failover Cluster Manager GUI unsupported

• No Active Directory

New-Cluster -Name cluster3 -Node server11,server12,server13 -AdministrativeAccessPoint DNS

server11 server12 server13

Workgroup1 Workgroup1

Cluster 3


Distributed Availability Groups

• Cross cluster Availability Groups

• Addresses Site-to-site latency, disconnected remote site and quorum considerations

• Forwarding Secondary synchronises with forwarded secondaries.

server1

Cluster 1, Availability Group X

server2 server3

server4

Server5

Cluster 2, Availability Group Y

Async replication streamFP

S S S

53m


Other new features

• MSDTC Support in Availability Groups

• Database level failover• (but see https://connect.microsoft.com/SQLServer/feedback/details/2051070)

• Log shipping transport improvements

• Azure Replica Wizard

• Group Managed Service Accounts (gMSA)

• 3 synchronous replicas (3 auto failover targets)

• Cluster Operating System Rolling Upgrade

• Storage Replica

• File Snapshot Backup


Thank you for listening!

Email: [email protected]

Twitter: retracement

Blog: http://tenbulls.co.uk

http://tenbulls.co.uk/

Date post:	16-Apr-2017
Category:	Technology
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Schizophrenic High Availability with SQL and Windows 2016

Technology