Zero-Flows

Scalable, versatile & brokerless messages flows.

This is what ZeroFlows brings us!

• Messages flows : we build directed graphs (potentially cyclic), and each step of the flow is managed by a service type. ZeroMQ is the key component for the transport part, then services exchange messages.
• Scalable : each step of the flow is managed by several services of the same service type, and you can deploy as many services you need to afford the load at this step. Each service discovers its peers thanks to Zookeeper.
• Versatile : the interconnection is continuously monitored by each service, for each service type, and adapted if a change is noticed.
• Brokerless : no central point is mandatory to route messages, so if you need one, Zero-Flows is a good basis to build one!

A service is a set of public endpoints, some bond to network adresses, some connected to other endpoints. In facts it does not matter the number of threads / processes / hosts hosting a service.

This is not a competitor for Actors frameworks as Akka (even if it achieves the same goal), because it is much more raw and simplistic.

License

Zero-Flows belongs to Jean-François SMIGIELSKI and all the contributors to the project, and is distributed under the terms of the GNU Lesser General Public License.

Third-party dependencies

• ZeroMQ >= 3.2.3
• Zookeeper >= 3.4
• Jansson >= 2.4
• Gnome Library 2 >= 2.30

ZeroMQ provides a taste of a brokerless BUS, the elementary transport unit is a message. Zero-Flows lets you benefit of PUSH/PULL (1 to Any) and PUB/SUB (1 to Any) patterns of communcation. Zookeeper is used to configure the nodes and discover the peer nodes. We only use the single-threaded C client API provided with the official Zookeeper distribution. Jansson is used to parse the JSON format used into Zookeeper. The Gnome library 2 provides easy-to-use data structures and a lot of necessary features.

Installation

Zero-Flows is built with the cmake and make, and relies on pkg-config to locate ZeroMQ and Jansson.

# git clone https://github.com/jfsmig/zeroflows.git
# cd /tmp
# cmake \
        -DZK_LIBDIR=${ZK_BASEDIR}/lib64 -DZK_INCDIR=${ZK_BASEDIR}/include \
        -DCMAKE_BUILD_TYPE=Debug \
        -DCMAKE_INSTALL_PREFIX=/tmp \
        ~/public_git/zeroflows
# make install

Feel free to read the cmake documentation if you want to a complete information about the configuration directives currently available.