The ClojureWerkz Blog

News and updates about ClojureWerkz projects

EEP 1.0.0-alpha5 Is Released

EEP (Embeded Event Processing) is a Clojure stream processing library.

1.0.0-alpha5 is a development milestone that introduces several minor API improvements and bug fixes.

Changes between 1.0.0-alpha4 and 1.0.0-alpha5

Fixed a problem with repeated emitter evaluation

build-topology had a bug that caused emitter given in the form of (create) to be re-evaluated each time the topology was updated. The bug does not affect codebases that use a single emitter instance bound to an existing var.

Fixed a problem with add-handler not returining an instance of emitter

Usually an emitter is stored in a var, but if you use a threading macro such as -> to build topologies, add-handler failed because it returned a caching registry. Thew new version returns the emitter, allowing for threading macros to work.

Optional downstreams argument for properly visualising splitters.

Because splitters only receives a function that’s responsible for the routing, it’s impossible for EEP to know where the events are routed after split. You can define a splitter with an array of all possible splits to make data flow visualisation possible.

For exmaple, following splitter will split events to even and odd ones. Along with splitter function, pass an vector of [:even :odd] so that visualiser would catch it.

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(defsplitter *emitter* :entrypoint (fn [i] (if (even? i) :even :odd)) [:even :odd])

Changes between 1.0.0-alpha3 and 1.0.0-alpha4

Meltdown is updated to 1.0.0-aplha3

Meltown alpha3 is a release with minor API additions.

Fixed problem with RingBuffer dispatcher overflow

RingBuffer operates in it’s own pool, adding notifications blocks RingBuffer’s yielding, therefore notify function block forever.

EEP now has realistic throughput tests that verify that the issue is gone.

Added more options to emitter constructor

It is now possible to pass backing Dispatcher for reactor that’s handling routing for the Emitter and an environment.

Change log

EEP change log is available on GitHub.

EEP is a ClojureWerkz Project

EEP is part of the group of libraries known as ClojureWerkz, together with

  • Langohr, a Clojure client for RabbitMQ that embraces the AMQP 0.9.1 model
  • Elastisch, a small feature complete Clojure client for ElasticSearch
  • Cassaforte, a Clojure Cassandra client
  • Monger, a Clojure MongoDB client for a more civilized age
  • Titanium, a Clojure graph library
  • Meltdown, a fast message passing library built on top of Reactor
  • Welle, a Riak client with batteries included
  • Quartzite, a powerful scheduling library

and several others. If you like Elastisch, you may also like our other projects.

Let us know what you think on Twitter or on the Clojure mailing list.

Michael on behalf of the ClojureWerkz Team