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All nodes should be in the same subnetNodes can be in different networksAmazon EC2 nodes
All nodes should be in the same multicast domainNo multicasting requirementNo multicasting requirement
Multicasting should not be blockedNo multicasting requirementNo multicasting requirement
No fixed IP addresses or hosts requiredAt least one well-known IP address or host required.No fixed IP addresses or hosts required
Failure of any member does not affect membership discoveryNew members can join with some WKA nodes down, but not if all WKA nodes are down.Failure of any member does not affect membership discovery
Does not work on IaaSs such as Amazon EC2IaaS-friendlyWorks on Amazon EC2
No WKA requirementRequires keepalive, elastic IPs, or some other mechanism for re-mapping IP addresses of WK members in cases of failure.No WKA requirement


Note that some production environments do not support multicast. However, if your environment supports multicast, there are no issues in using this as your membership scheme.

titleAbout Well-Known Addresses (WKA)

The Well-Known Addresses (WKA) feature is a mechanism that allows cluster members to discover and join a cluster using unicast instead of multicast. WKA is enabled by specifying a small subset of cluster members (referred to as WKA members) that are able to start a cluster. The WKA member starts the cluster and the other members join the cluster through this WKA member. When the WKA member is down, the cluster breaks, and the members cannot communicate with each other.

The system should have at least two well-known address (WKA) members in order to work correctly and to recover if a single WKA member fails.