NiFi-WebSocket

Work-in-Progress

The goal of this project is to enable WebSocket interface to NiFi so that, external clients can send data to a flow as well as NiFi can stream results back to clients like browsers. To simplify usage, STOMP over WebSocket protocol is used for client/server communication.

1. VertxService is a NiFi service that opens WebSocket port and bridge the embedded vertx's EventBus.
2. GetEventBus is a NiFi processor that subscribe to EventBus's address. all messages received on the address will be emitted into the flow.
3. SendEventBus is a NiFi processor that sends flowFile to EventBus address (point-to-point). only one recipient will receive flowFile.
4. PublishEventBus is a NiFi processor that publish flowFile to EventBus address (pub/sub). all subscribers on the address will receive flowFile.

Install

1. Manual: Download Apache NiFi binaries and unpack to a folder.
2. On Mac: brew install nifi

Deploy

# Assume you unpacked nifi-0.3.0-bin.zip to /Developer/Applications/nifi
./gradlew clean deploy -Pnifi_home=/Developer/Applications/nifi

On Mac

gradle clean deploy -Pnifi_home=/usr/local/Cellar/nifi/0.3.0/libexec

Run

cd /Developer/Applications/nifi
./bin/nifi.sh  start
./bin/nifi.sh  stop

On Mac

# nifi start|stop|run|restart|status|dump|install
nifi start 
nifi status  
nifi stop 
# Working Directory: /usr/local/Cellar/nifi/0.3.0/libexec

Test

1. check if SockJS server is up: http://hostname:{port}/{eventbus}/info
2. test evenBus via web page: test.html
3. test with flow: WebSocketFlow.xml

TODO

1. Try HazelcastClusterManager and Vertx.clusteredVertx to see if vertx clustering is possible with NiFi cluster.
2. Support ability to publish multiple types of messages. i.e., primitives, string, buffers, JSON