Service Fabric (continued)     

Part 2 compared Paxos and Raft. Part 3 discussed SF-Ring and Part 4 discussed its architecture. This article describes how to configure Service Fabric clusters

The Service Fabric managed cluster SKU is a starting point for creating a Service Fabric cluster. There are several other ways to configure it. These include:

1.       Adding a virtual machine scale set extension to a node type - Each node type in a service fabric managed cluster is backed by a virtual machine scale set (vmss). It enables us to add vmss extensions that are small applications that provide post-deployment configuration and automation on Azure VMs. Extensions take mandatory parameters and simplify the installation.

2.       Configuring cluster availability zone spanning – Service fabric clusters can span availability zones in the same region which provide low latency network and high availability. Azure availability zones are only available in select regions.

3.       Configuring cluster network settings – Service Fabric managed clusters are created with a default network configuration which consists of a load balancer, public IP, VNet with one subnet allocated, and a NSG configured for essential cluster functionality. The settings of this network can be configured with NSG rules, RDP access, Load balancer config, IPV6, custom virtual network, custom load balancer, accelerated networking, and auxiliary subnets.

4.       Configuring a node type for large vmss – which are created by specifying the multiplePlacementGroups in added to the nodeType definition. Managed cluster node types set this property to false to keep fault and upgrade domains consistent within a placement group but it can be set for large vmss.

5.       Configuring managed identity - which are specified by a property vmManagedIdentity that has been added to node type definitions and contains a list of identities that may be used.

6.       OS and Data encryption – The disk encryption options are selected with the recommendation that the encryption be set at host. This improves on Azure disk encryption by supporting all OS types and images, including custom images.

7.       Autoscaling - which gives great elasticity and enables addition or reduction of nodes on demand on a secondary node type. The rule for the workload can be configured and autoscaling handles the rest.

8.       Scaling a node type – A service fabric managed cluster node type is scaled with portal, ARM template or PowerShell. We can also configure autoscale for a secondary node type if a fully automated solution is needed.

9.       Enabling Automatic OS image upgrades – This is a choice for the user even though the Service Fabric managed clusters manages the vmss resources.

10.   Modifying the OS SKU for a nodeType – This is helpful for scenarios such as migrating from earlier version of Windows to later or from switching one SKU to another.

11.   Configuring placement properties – These are used to ensure that certain workloads run only on certain node types in the cluster

12.   Managing the disk type SKU such that managed disks are used for all storage types so that the disk type and size are not provisioned.

13.    Configuring the cluster upgrade options such as wave deployment for automatic upgrades

This rounds up the configurations for the service fabric cluster.