Core group transports
Transport types include...
- Channel framework transport (default)
- Unicast transport
The HA Discovery Protocol verifies that connections are opened to all core group members.
Each core group member has a configured endpoint knows as the DCS_UNICAST_ADDRESS, which contains host and port information.
Channel framework transport
The default channel framework transport has slightly lower performance than the Unicast transport. This performance impact is a concern in the most demanding topologies, where memory-to-memory session replication throughput is a primary objective.
With a channel framework transport, all communication occurs directly over the core group TCP/IP connections.
To use a channel framework transport for distribution and consistency services (DCS) messages, in addtion to the DCS_UNICAST_ADDRESS endpoint, configure either...
- DCS transport chain (default)
- DCS_SECURE transport chain
A DCS_SECURE transport chain includes both a TCP channel and an SSL channel.
The channel framework transport supports...
- Combining channels to create custom transport chains.
- Port sharing
LTPA tokens are used to authenticate incoming connection requests if administrative security is enabled.
Unicast transport
Support for unicast transports is deprecated. You should use the channel framework transport as the transport type whenever it is possible to do so
Unicast transports use standard network connections, rather transport chains, for core group members communication.
Because a unicast transport does not go through the channel framework, communication is somewhat faster than the channel framework transport, which could be useful in topologies that make extensive use of memory-to-memory session replication. This performance gain is achieved at the cost of using additional ephemeral ports.
A unicast transport has fewer security options than the channel framework transport. If administrative security is enabled for WAS ND, an LTPA token is used to authenticate all incoming connection requests. However, no SSL encryption option is available for a unicast transport.
Because a unicast transport uses more ephemeral ports than a channel framework transport, it might not scale as well as a channel framework transport does as the core group size increases.
Related concepts
Core groups (high availability domains)
Core group discovery and failure detection protocols
Related tasks
Configure a core group transport