Transcript Stretching failover clusters and using storage replica in windows







But what if there is a
catastrophic event?
Fire, flood, earthquake …

app’s fail over to a
separate physical
location
Servers in
separate locations
in the same cluster
Recovery Time Objective (RTO)




Recovery Point Objective (RPO)
Different datacenters (usually) equates to different subnets
Longer distance means greater network latency
WAN
Property
Default
Recommended
SameSubnetDelay
1
1
SameSubnetThreshold
5
10
CrossSubnetDelay
1
1
CrossSubnetThreshold
5
20
Description
Frequency heartbeats (HB) sent
Missed HB before interface considered down
Frequency HB sent to nodes on dissimilar subnets
Missed HB before interface considered down to
nodes on dissimilar subnets
PowerShell:
(Get-Cluster).SameSubnetThreshold = 10
(Get-Cluster).CrossSubnetThreshold = 20




Network Name Resource

OR
OR
IP Address
Resource A
IP Address
Resource B

Dependencies in Cluster Validation Report
DNS Replication
DNS
Record Created
DNS
Record Updated
Record Obtained
Client access
point fails
across subnets
Record Updated
Client needs
new address
10.10.10.10
20.20.20.20
Nodes in dissimilar subnets






30.30.30.30
10.10.10.10
Network
Virtualization
20.20.20.20
 RegisterAllProvidersIP




 HostRecordTTL


PowerShell syntax:
Get-ClusterResource ClusNN | Set-ClusterParameter RegisterAllProvidersIP 1
Get-ClusterResource ClusNN | Set-ClusterParameter HostRecordTTL 300




DNS
10.10.10.10
DNS
20.20.20.20
VM = 10.10.10.111


DNS Server 1
DNS Server 2
DNS
DNS
VLAN
10.10.10.10
10.10.10.10
FS = 10.10.10.111



http://www.cisco.com/en/US/docs/solutions/Enterprise/Data_Center/App_Networking/extmsftw2k8vistacisco.pdf
DNS Server 2
30.30.30.30
DNS
DNS
DNS Server 1
10.10.10.10
20.20.20.20
VM = 30.30.30.30


Value
Description
0
Clear Text
1
Signed (default)
2
Encrypted
PowerShell syntax:
(Get-Cluster). SecurityLevel = 2
Adjust intra-node heartbeat thresholds
Understand NetName Resource Configuration
Optimize Client Reconnection on CAP Failover
Encrypt intra-node communication over unsecure WANs



Each node can have 1 vote
Witness can only have 1 vote


Vote
5
Site 1 can reach
Cloud Witness!
Cluster Survives!
Site 2
Down!!!
Vote
Vote
1
Vote
2
Vote
3
4






Azure
Witness
http://blogs.msdn.com/b/clustering/archive/2014/11/14/10572766.aspx
Cloud Witness
File Share Witness
Share the same arbitration logic
Do not keep copy of cluster database




Cluster
Site 1
Site 2




Recovery of Primary Site:
Loss of Primary Site:
Start-ClusterNode -PreventQuorum
Start-ClusterNode -ForceQuorum
Vote
Vote
1
2
3
4




PowerShell syntax:
Get-ClusterGroup MyVM | Set-ClusterOwnerNode Node1, Node2
Recommended to use Cloud Witness
When no access to Azure use File Share Witness in a 3rd site
Automatic failover – Keep number of nodes on
primary and secondary sites equal
Manual failover – Remove votes of nodes on
secondary site
“Can you hear me now?”
Chicago (you are here)
NYC
Replication
Block-level, volume-based
Synchronous & asynchronous
SMB 3.1.1 transport
Flexibility
Any Windows volume
Any fixed disk storage
Any storage fabric
Management
Failover Cluster Manager
Windows PowerShell
WMI
End to end MS Storage Stack
Cluster
Site1
Site2
Applications
(local or remote)
1
5
2
Source Server
Node (SR)
t
Data
4
2
Log
Destination Server
Node (SR)
t1
Data
3
Log






http://aka.ms/moderninfrastructure
http://aka.ms/deployinghyperv
http://aka.ms/cloud-platform-ebook
http://aka.ms/virtualization-lab
http://aka.ms/wap-lab
@MS_ITPro
http://myignite.microsoft.com