As everyone know Lync Server 2013 introduced a new Disaster Recovery feature called “Pool Pairing”, where we can deploy two FE pool across the two physical location, each site contain a Front End pool, which can paired with Front End pool with another site, both site can be active and a new Lync server backup service provides real-time data replication to keep the pools synchronized. Lync Backup service is installed on front end server, designed to support the disaster recovery solution.
One of the best feature is pools are active-active so both pools can be serving their own associated users, and we do have enough capacity on one pool to cater for its own users as well as those of its partner if failover were to occur.
Each pool will act as backup for other pool, as we can only pair pools only with 1:1 ratio, and each pool should consist of servers that are patched to the same level.
Supported pool pairing scenario
Standard edition pool --> Standard edition pool
Enterprise edition pool --> Enterprise edition pool
Physical pool --> Physical pool
Virtual pool --> Virtual pool
Pool failover and pool failback target for recovery time objective (RTO) is 15 minutes, this is the required for the failover to happen.
Now we will see how complete process for pool failover.
First, i can see lync topology builder with details, i do have two FE pools.
Click on Edit and select Resiliency and check the "Associated backup pool" and drop down select the pool.
you can also select the automatic failover and failback options.
Once complete publish the topology
Now install the Lync Server 2013 component from deployment wizard
you can see in between Lync Backup service getting installed
Now you can also check the Lync Server backup service is running on Front End Server
Once we added the "Associated Backup Pool" , we should invoke backup service to start the initial sync.
To get the status of the backup service
One other thing of note, we need to create SRV for new pool- Pool2.Tech.Com pointing to our new server.
Now you can verify the DNS records
Now you can also check the client level connectivity
When we establish a pool pairing that includes the pool hosting the Central Management store, a backup Central Management store database is set up in the backup pool, and Central Management store services are installed in both pools. At any point in time, one of the two Central Management store databases is the active master, and the other is a standby. The content is replicated by the Backup Service from the active master to the standby.
During a pool failover that involves the pools hosting the Central Management store, the administrator must fail over the Central Management store before failing over the Front End pool.
RTO & RPO is 5 mins for CMS failover.
Now i have disabled network for primary Pool
i can see the affect in client side "error showing limited functionality"
Now you can check the CMS details with cmdlet
Now you can check details with
"Invoke-CsPoolfailover -Pool.tech.com -disasterMode -verbose"
Lync Server 2013 has a target RTO and RPO of 15 minutes for a pool with 40,000 concurrent users (this would be Enterprise Edition). This means we should expect to have a similar RTO and RPO for a Standard Edition deployment. Keep in mind the clock on the RTO doesn’t start until a disaster is declared and administrators can start fixing the problem.
With the introduction of paired pools, organizations can now easily adopt Lync and all its workloads. Voice and conferencing are absolutely Tier 1 applications and the architecture changes in Lync 2013 will meet enterprises’ requirements for Tier 1 Disaster Recovery.