A CHIEVING SITE R ESILIENCY WITH E XCHANGE SERVER Pradeep Kini

W HY ARE SERVICES IMPORTANT ? The total number of worldwide accounts is expected to increase from 3.3billion accounts in 2012 to over 4.3 billion accounts by year-end Most of the world’s traffic comes from the corporate world. In 2012, the number of businesses s sent and received per day total 89 billion. This figure is expected to grow at an average annual rate of 13% over the next four years, reaching over 143 billion by year-end 2016.

Businesses rely on s for mission critical activities, Business cannot sustain with service unavailability and performance. Unavailability or downtime on systems erodes brand.

N EW FUNCTIONALITY WITH 2010 SP1 Block mode Replication Enhancements to DAC Improved Failover / switchover performance Enhancements in EMC to manage DAG IP and Alternate witness server ESE Recovery from hung I/O

Database Availability Group A group of up to 16 servers hosting a set of replicated databases Built on top Windows Failover Cluster  Manages server membership in the DAG  Heartbeats, quorum, cluster database Defines the boundary of database replication Defines the boundary of failover/switchover (*over) Defines boundary for DAG’s Active Manager

S IMPLIFIED NATIVE SOLUTION DB1 DB2 DB4 DB5 DB1 DB2 DB4 DB5 DB3

HA FOR CAS & T RANSPORT SERVER ROLES Load Balanced CAS roles DNS based load balancing Multiple Hub transport servers installed in site Load Balance Hub transport for Internet and messages from LOB applications/ third party mail servers. Why is use of WLB / NLB not recommended ?

U SE H ARDWARE L OAD B ALANCERS Windows NLB does not work with Failover clustering Maximum recommended eight nodes Does not detect service outage, works on IP Causes switch/ port flooding Supports Client affinity using source IP only.

A CTIVE M ANAGER Process run under the MS Exchange Replication service. Primary Active Manager – Node that owns the cluster core resource standby Active Manager – All other Participating DAG Nodes. Responsible for detection and activation of Database on Failure.

BCS Copy queue length Replay queue length Database status Content index status

C ERTIFICATE P LANNING Use a Single Certificate for all Datacenters Use SAN Certificate Same Cert Principal Name to be used Set outlook provider in Active Directory to use the cert principal name in Microsoft standard form (msstd) Set-OutlookProvider EXPR -CertPrincipalName "msstd:mail.Securesine.com"

DNS R EQUIREMENT Define the TTL for records based on RTO Specify SPF record with DR IP addresses. Change MX record during DC failover to point to DR Eliminate SPOF Use Multiple Service providers

K EY CONSIDERATIONS Plan AD sites Name Space Planning User Distribution Datacenter Models

DAC M ODE Prevent Split Brain Active Manager stores a DACP bit 0/1 that decides Database mount operation. In Two member DAG, boot time of the alternate witness server is considered. If the time the DACP bit was set is earlier than the boot time of the alternate witness server – Database isn't mounted. If the time that the DACP bit was set is more recent than the boot time of the alternate witness server – Databases Mounted.

DAC CMDLETS Set-DatabaseAvailabilityGroup -Identity jet - DatacenterActivationMode DagOnly Stop-DatabaseAvailabilityGroup -Identity jet – ActiveDirectorySite Bangalore Restore-DatabaseAvailabilityGroup -Identity jet - ActiveDirectorySite mumbai Start-DatabaseAvailabilityGroup -Identity jet – ActiveDirectorySite Bangalore

Scenario 1: Active/ Passive Datacenters

A CTIVE / A CTIVE DC

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