Currently TailFile only works on a systems local system. In order to coordinate receiving data from a remote host there is numerous different options and configurations that need to be taken into account. Tail File was designed to fulfill a targeted goal, tail a local file. This is done to create a smaller building block which can build up the bigger system and is easier to re-use for multiple different applications. Getting log file data off a remote host with all the perks of NiFi is something we are working toward with a sub-project tentatively called "MiNiFi". There is a design proposal requesting feedback here: "http://apache-nifi-developer-list.39713.n7.nabble.com/DISCUSS-Proposal-for-an-Apache-NiFi-sub-project-MiNiFi-td6141.html". Please reply with any comments or suggestions! ... View more

Andrew is correct in regards to the difference between ${uuid} and ${UUID()} but the reason why ${uuid} doesn't work is because the GetHTTP processor doesn't evaluate the expression language in relation to the new flowfile. As you can see on this line: https://github.com/apache/nifi/blob/528dab78d6dbc3bb4f61663f423b07284936ec40/nifi-nar-bundles/nifi-standard-bundle/nifi-standard-processors/src/main/java/org/apache/nifi/processors/standard/GetHTTP.java#L476 It calls "evaluateAttributeExpressions()" with no parameters so the "uuid" of the new flowfile is outside the scope of the expression language when being evaluated. If you want to re-use the UUID for the FlowFile you can use an UpdateAttribute processor to append the UUID to "./downloads/". ... View more

What you're looking for is a patch that was recently merged into master:https://issues.apache.org/jira/browse/NIFI-447 It allows the ReplaceText processor to do multiple new things such as prepend or append a property (expression language supported) to either every line or the whole flowfile. ... View more

1: The ports needed are the UI ports (http and/or https) and any ports needed by processors for data. The two config properties are: nifi.web.http.port and nifi.web.https.port. 2: Unicasting is used by default for the clustered environment and multicasting isn't needed. Multicasting is used to facilitate broadcasting the availability of a NiFi NCM service. Though there are some network topologies that disable multicasting. So all the multicasting properties are blank since they aren't used by default. If you're looking for a good guide to setting up a simple cluster you can find one here: https://kisstechdocs.wordpress.com/2015/01/15/simple-tasks-in-nifi-creating-a-super-simple-cluster/ 3: Site-to-site is a bit tricky with the word "port". When talking about NiFi only, there are "Input Ports" and "Output Ports" for "Remote Processes Groups" (RPG). All of the RPG's input ports are fed via the network port set with this NiFi system property "nifi.remote.input.socket.port". For connections leaving a NiFi instance, whether thats via a RPG's output port or a processor like HttpGet, a random port that's available will be allocated by the system and the connection kept open. It will be closed after a period of inactivity. ... View more