Roadmap v0.2 - Journal

[huachaohuang]

Tasks:

• Design document
• Journal abstraction
• A memory implementation
• A file journal implementation #128
• A grpc journal implementation #117

[Little-Wallace]

How we create a journal stream with other params? If one tablet is ready to split to two tablet, it means that we shall create one new journal for the new tablet.

[huachaohuang]

How we create a journal stream with other params?

We can allow users to create a stream with some metadata and persist the metadata in Journal. Users may also consider storing metadata in Kernel. Kernel only supports one stream for now, but we will allow users to create multiple streams sooner or later.