0.4.0

Release 0.4.0 ships directed, acyclic graph workflows, catalog-level grouping, and multiple bug fixes. 0.4.0 breaks backwards compatability with the previous release - 0.3.3. These changes are outlined below. See the changelog for full details.

• :onyx/type no longer accepts :transformer, :aggregate, or :grouper. Transformations are now solely specified with :onyx/type being keyed to :function.
• Grouping takes place inside the catalog entry by either setting :onyx/group-by-key or :onyx/group-by-fn. The former groups all segments with the same key value to the same Onyx peer. The latter uses a keyword that points to a function on the classpath to group segments by an arbitrary function.
• Aggregation can happen implictly anywhere, and is fully in the hands of the user.
• Workflows may now be a vector-of-vectors, which specifies a directed acyclic graph. See the information model documentation for a full specification. Onyx remains fully backwards compatible with the original tree-based workflows that it shipped in 0.3.x.
• Message acknowledge is no longer on its own thread, and has been removed from the pipeline interface.
• read-batch requires a sequence of maps to be returned, where each map is keyed with :input and :message, signaling the ingress source and message content, respectively.
• read-batch must not perform a blocking read longer than :onyx/batch-timeout ms in the catalog entry. The default is 1000 ms. All plugins must respect this.

Upgrade notes:

• Onyx 0.4.0 is incompatible with previous versions, and requires a restart of the Coordinator and all Peers.

Misc:

• Transducer support will be moved to release 0.5.0, and will be held until Clojure 1.7.0 officially ships.

A special thanks to all contributors:

• Bruce Durling
• Malcolm Sparks
• Lucas Bradstreet
• Bryce Blanton