Production service fabric cluster minimum node count

Question

Can someone clarify if we can run on-prem Service fabric production clusters with 3 nodes rather than the minimum requirement of 5 nodes. Of course application performance will be degraded but is it possible to do so.

Answer 1

Hello @Krishnan, Viswanathan - Thanks for reaching out.

We require a production cluster to have at least five nodes because of the following three reasons:

• Even when no user services are running, a Service Fabric cluster runs a set of stateful system services, including the naming service and the failover manager service. These system services are essential for the cluster to remain operational.
• We always place one replica of a service per node, so cluster size is the upper limit for the number of replicas a service (actually a partition) can have.
• Since a cluster upgrade will bring down at least one node, we want to have a buffer of at least one node, therefore, we want a production cluster to have at least two nodes in addition to the bare minimum. The bare minimum is the quorum size of a system service as explained below.

Please take a look at this document for more reference : Minimum Size of SF Cluster

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