Recently, I had a requirement to host and test a Workflow Manager farm in Azure IaaS with SharePoint 2013. The key element here was to ensure high availability for the SharePoint farm and the Workflow Manager farm as part of the design. This can be achieved by appropriately spreading your farm tier across availability sets, to ensure that the appropriate roles are available during host patching. This, of course, would include the database tier, where you could utilize SQL Server AlwaysOn Availability Groups in synchronous commit mode to achieve maximum uptime.

Cloud Services Generally, you would want to have separation between the SharePoint farm, SQL infrastructure and the workflow manager farm. I personally would recommend using the new regional networks in Azure so that you can utilize internal load balancers required for Workflow Manager high availability. The picture below depicts a very basic farm with high level components, including Workflow Manager within its own cloud service.

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Internal load balancers are used for SQL Server AlwaysOn, currently supporting one AG in Windows Azure since the Internal Load Balancer (ILB)  supports only one IP address. The SharePoint farm would access SQL Server ideally via a DNS record pointing to the load balanced IP. The SQL Servers would expose the SQL Server endpoint port to the internal load balancer used by the SQL Server Availability Group for connectivity. Synchronous commit mode is utilized on the Availability group to maximise uptime. Since this topic is about Workflow Manager high availability, we would have three instances hosted within a cloud service being exposed via a internal load balancer. This should ideally be on port 12290 (https) for the farm to communicate to the Workflow Manager endpoint. It’s recommended to utilize a domain certification authority (CA), to have a trusted certificate between all the Workflow Manager nodes and Workflow clients. A common question is why would we just not have two servers in the Workflow Manager farm? Basically, Service Bus, utilizes a quorum, so a third node is required for High Availability.

Configuration

• Prior to configuring the Workflow Manager farm, ensure you have all the Azure VMs provisioned as part of a cloud service and install the Workflow and Service Bus, with the refresh versions and Service Bus 1.1. All nodes in the farm should have the same bits installed, otherwise your configuration may fail.
• Ensure each host has a certificate issued by a domain CA and you have the certificate installed on all three nodes. The certificate must be trusted by the SharePoint Servers, otherwise you’d have a JSON download error message when you try and register and configure the Workflow Manager Proxy
• Ensure you have a DNS Host (A) entry created, pointing to the ILB IP address,  in the domain which is tied to the common name issued by the domain CA (after you create the Internal Load Balancer)
• The workflow manager installer account must be a local administrator on all three farm nodes
• The workflow manager installer account must have the Server Admin role in SQL Server, although I have made this work with DBCREATOR and SECURITY ADMIN in the past, the Workflow Manager articles still suggest the SA role
• The Workflow Manager RunAs Account must be a domain account and have the log on as a service right (make sure your domain policies do not override this security policy

Create the Internal Load Balancer in Azure

For this step you’ll require:

• The Cloud Service Name
• The VNet Subnet (for assigning the IP address to the ILB)

Run the following PowerShell to create the ILB:

# Internal Load Balancer Settings – replace these settings with your own environment settings

$ILBName = “ILBSBWorkflow”

$ILBSubnet = “WFSubNet”

$EndPointName = “IntSBWFEndPoint”

$WFHTTPSPort = “12290”

$PoleInterval = “20”

$ServiceName = “WORKFLOWCSVC”

$WFVM1 = “WF01”

$WFVM1 = “WF02”

$WFVM1 = “WF03”

# Add Internal Load Balancer to the service

Add-AzureInternalLoadBalancer -InternalLoadBalancerName $ILBName -SubnetName $ILBSubnet -ServiceName $ServiceName

Expose and Assign the Endpoints to the ILB

Run the following PowerShell the create and expose the endpoint on the Virtual Machines, which participate in the load balanced set.

# Add load balanced endpoints to ILB for Workflow Manager

Get-AzureVM -ServiceName $ServiceName -Name $WFVM1 | Add-AzureEndpoint -Name $EndPointName -LBSetName $ILBName -Protocol tcp -LocalPort $WFHTTPSPort -PublicPort $WFHTTPSPort -ProbePort $WFHTTPSPort -ProbeProtocol tcp -ProbeIntervalInSeconds $PoleInterval -InternalLoadBalancerName $ILBName | Update-AzureVM

Get-AzureVM -ServiceName $ServiceName -Name $WFVM2 | Add-AzureEndpoint -Name $EndPointName -LBSetName $ILBName -Protocol tcp -LocalPort $WFHTTPSPort -PublicPort $WFHTTPSPort -ProbePort $WFHTTPSPort -ProbeProtocol tcp -ProbeIntervalInSeconds $PoleInterval -InternalLoadBalancerName $ILBName | Update-AzureVM

Get-AzureVM -ServiceName $ServiceName -Name $WFVM3 | Add-AzureEndpoint -Name $EndPointName -LBSetName $ILBName -Protocol tcp -LocalPort $WFHTTPSPort -PublicPort $WFHTTPSPort -ProbePort $WFHTTPSPort -ProbeProtocol tcp -ProbeIntervalInSeconds $PoleInterval -InternalLoadBalancerName $ILBName | Update-AzureVM

Create your DNS host entry to point to the load balanced address for Workflow Manager. To determine the IP address of the ILB, if you have not assigned one yourself when you created the ILB, you can run the following PowerShell:

Get-AzureInternalLoadBalancer -ServiceName $ServiceName

Install and configure the first Workflow Manager node and join the remaining nodes to the Workflow Manager farm. Check the farm is operational by running the following PowerShell:

Get-SBFarmStatus

Get-WFFarmStatus

Register the Workflow Manager Proxy

$SPWebApp = “https://webapplication”
$SPWorkFlowHostURI = “https://WORKfLOWADDRESS:12290”
Register-SPWorkflowService -SPSite $SPWebApp -WorkflowHostUri $SPWorkFlowHostURI