gorums

Gorums [1] is a novel framework for building fault tolerant distributed systems. Gorums offers a flexible and simple quorum call abstraction, used to communicate with a set of processes, and to collect and process their responses. Gorums provides separate abstractions for (a) selecting processes for a quorum call and (b) processing replies. These abstractions simplify the main control flow of protocol implementations, especially for quorum-based systems, where only a subset of the replies to a quorum call need to be processed.

Gorums uses code generation to produce an RPC library that clients can use to invoke quorum calls. Gorums is a wrapper around the gRPC library. Services are defined using the protocol buffers interface definition language.

Examples

The original EPaxos implementation modified to use Gorums can be found here.

A collection of different algorithms for reconfigurable atomic storage implemented using Gorums can be found here.

Outdated documentation

• Student/user guide
• Developer guide

Adding a new extension option (TODO Move this to devguide)

1. Add your extension option to gorums.proto. We currently only have method options.
2. Run make gorumsprotoopts to regenerate the gorums.pb.go file. (TODO we could probably avoid using a make file for this and instead do go generate)
3. Add a check function, such as hasPerNodeArgExtension(), for your option in plugins/gorums/ext.go.
4. Update the plugins/gorums/gorums.go as follows a. add the option PerNodeArg bool to the serviceMethod struct. b. add the option to initialize of the serivceMethod struct in the verifyExtensionsAndCreate function, like this: PerNodeArg: hasPerNodeArgExtension(method), c. update the logic in the isQuorumCallVariant function if necessary. d. update the error handling logic in verifyExtensionsAndCreate.
5. Update the template files (.tmpl in dev folder) related to your option. This is were your on your own.
6. To regenerate the gorums plugin, you need to run make goldenanddev so that new proto files will understand your option.
7. Update the dev/register.proto file with your new option (probably on a new method).
8. To use the new option in the dev/register.proto file, you need to run make devproto.

References

[1] Tormod E. Lea, Leander Jehl, and Hein Meling. Gorums: New Abstractions for Implementing Quorum-based Systems. In submission.