Introduction

Cluster wide IPC service

Have you ever wished you had the convenience of Unix Domain Sockets even when transmitting data between cluster nodes? Where you yourself determine the addresses you want to bind to and use? Where you don't have to perform DNS lookups and worry about IP addresses? Where you don't have to start timers to monitor the continuous existence of peer sockets? And yet without the downsides of that socket type, such as the risk of lingering inodes?

Welcome to the Transparent Inter Process Communication service, TIPC in short, which gives you all of this, and a lot more.

Service Addressing

A fundamental concept in TIPC is that of Service Addressing which makes it possible for a programmer to chose his own address, bind it to a server socket and let client programs use only that address for sending messages.

Service Tracking

• A client wanting to wait for the availablity of a server, uses the Service Tracking mechanism to subscribe for binding and unbinding/close events for sockets with the associated service address.
• The service tracking mechanims can also be used for Cluster Topology Tracking, i.e., subscribing for availability/non-availability of cluster nodes.
• Likewise, the service tracking mechanims can be used for Cluster Connectivity Tracking, i.e., subscribing for up/down events for individual links between cluster nodes.

Transmission Modes

Using a service address, a client can send datagram messages to a server socket.

Using the same address type, it can establish a connection towards an accepting server socket.

It can also use a service address to create and join a Communication Group, which is the TIPC manifestation of a brokerless message bus.

Multicast with very good performance and scalability is available both in datagram mode and in communication group mode.

Inter Node Links

Communication between any two nodes in a cluster is maintained by one or two Inter Node Links, which both guarantee data traffic integrity and monitor the peer node's availability.

Cluster Scalability

By applying the Overlapping Ring Monitoring algorithm on the inter node links it is possible to scale TIPC clusters up to 1000 nodes with a maintained neighbor failure discovery time of 1-2 seconds. For smaller clusters this time can be made much shorter.

Neighbor Discovery

Neighbor Node Discovery in the cluster is done by Ethernet broadcast or UDP multicast, when any of those services are available. If not, configured peer IP addresses can be used.

Configuration

When running TIPC in single node mode no configuraton whatsoever is needed. When running in cluster mode TIPC must as a minimum be given a node address (before Linux 4.17) and told which interface to attach to. The "tipc" configuration tool makes is possible to add and maintain many more configuration parameters.

Performance

TIPC message transfer latency times are better than in any other known protocol. Maximal byte throughput for inter-node connections is still somewhat lower than for TCP, while they are superior for intra-node and inter-container throughput on the same host.

Language Support

The TIPC user API has support for C, Python, Perl, Ruby, D and Go.