This project is part of FIWARE, as part of the Core Context Management Chapter .

Cygnus is a is an easy to use, powerful, and reliable system to process and distribute data. Internally, Cygnus is based on Apache NiFi, NiFi is a dataflow system based on the concepts of flow-based programming. It supports powerful and scalable directed graphs of data routing, transformation, and system mediation logic. It was built to automate the flow of data between systems. While the term 'dataflow' is used in a variety of contexts, we use it here to mean the automated and managed flow of information between systems.

In order to talk about Cygnus, there are a few key terms that readers should be familiar with. We will explain those NiFi-specific terms here, at a high level.

FlowFile: Each piece of "User Data" (i.e., data that the user brings into NiFi for processing and distribution) is referred to as a FlowFile. A FlowFile is made up of two parts: Attributes and Content. The Content is the User Data itself. Attributes are key-value pairs that are associated with the User Data.

Processor: The Processor is the NiFi component that is responsible for creating, sending, receiving, transforming, routing, splitting, merging, and processing FlowFiles. It is the most important building block available to NiFi users to build their dataflows.

Cygnus is designed to run specific set of processors and templates for persistence context data to multiple sinks.

Current stable release is able to persist the following sources of data in the following third-party storages:

• NGSI-like context data in:
  • MySQL, the well-known relational database manager.
  • MongoDB, the NoSQL document-oriented database.
  • PostgreSQL, the well-known relational database manager.

Cygnus plays the role of a connector between Orion Context Broker (which is a NGSI source of data) and many external and FIWARE storages like MySQL, MongoDB

The Quick Start Guide is found at readthedocs.org provides a good documentation summary (Cygnus).

Nevertheless, both the Installation and Administration Guide also found at readthedocs.org cover more advanced topics.

The Processors Catalogue completes the available documentation for Cygnus (Cygnus).

Cygnus Except as otherwise noted this software is licensed under the Apache License, Version 2.0

   Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at
   
   http://www.apache.org/licenses/LICENSE-2.0
   
   Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.

Any doubt you may have, please refer to the Cygnus Core Team.