fi_tcp(7) Libfabric Programmer's Manual
fi_tcp - The msg sockets Fabric Provider
The tcp provider can be used on any system that supports TCP sockets. The provider is not intended to provide performance improvements over regular TCP sockets, but rather to allow developers to write, test,and debug application code even on platforms that do not have high-performance fabric hardware.
The following features are supported
- Endpoint types
- FI_EP_MSG is the only supported endpoint type. Reliable datagram endpoint over TCP sockets can be achieved by layering RxM over tcp provider.
FI_EP_RDM is supported by layering ofi_rxm provider on top of the tcp provider.
- Endpoint capabilities
- The tcp provider currently supports FI_MSG, FI_RMA
- Currently tcp provider supports only FI_PROGRESS_MANUAL
- Shared Rx Context
- The tcp provider supports shared receive context
- Multi recv buffers
- The tcp provider supports multi recv buffers
The tcp provider check for the following environment variables -
- A specific network interface can be requested with this variable
- These variables are used to set the range of ports to be used by the tcp provider for its passive endpoint creation. This is useful where only a range of ports are allowed by firewall for tcp connections.
- Default tx context size (default: 256)
- Default rx context size (default: 256)
The tcp provider is implemented over TCP sockets to emulate libfabric API. Hence the performance may be lower than what an application might see implementing to sockets directly, depending on the types of data transfers the application is trying to achieve.