Update NiFi Connection Destination via REST API

[#1]

Introduction

Recently a customer asked me how to change destination of a connection which still contains data, but the destination is stopped. Using NiFi REST Api we can change the flow, here in this article I am trying to capture steps to update destination of a connection using REST API. The requirement around this was to push incoming data to different flows on a timely manner.

Prerequisites

1) To test this, Make sure HDF-2.x version of NiFi is up an running

2) Minimum 3 processors are on the canvas with connection like below:

12507-data-flow-before.jpg

3) Note the destination's uuid [In my case 'PutNext' processor's uuid]

12506-putnext-uuid.jpg

4) Note the uuid of the connection that has to be made to the 'PutNext' processor

12505-connection.jpg

'GET'ing the details of connection

1) Execute the below command on your terminal with uuid of the connection:

curl -i -X GET http://localhost:8080/nifi-api/connections/dcbee9dd-0159-1000-45a7-8306c28f2786 

2) Now Copy the result of the GET curl command and update the below section with uuid of the 'PutNext' processor.

"destination":{"id":
"destinationId":"
"destinationId":

12504-changes-required.jpg

3) Remove the below json element from the copied result:

"permissions":{"canRead":true,"canWrite":true},

12503-remove-this-element.jpg

Updating Destination with PUT REST calls

1) Once updated, run the PUT REST API call from command line using curl as below:

curl -i -X PUT -H 'Content-Type: application/json'  -d  '{ **MY UPDATED JSON**}' http://localhost:8080/nifi-api/connections/dcbee9dd-0159-1000-45a7-8306c28f2786

My Sample command is as below:

curl -i -X PUT -H 'Content-Type: application/json'  -d  '{
    "revision": {
        "clientId": "dd1c2f03-0159-1000-845b-d5c732a49869",
        "version": 15
    },
    "id": "dcbee9dd-0159-1000-45a7-8306c28f2786",
    "uri": "http://localhost:8080/nifi-api/connections/dcbee9dd-0159-1000-45a7-8306c28f2786",
    "component": {
        "id": "dcbee9dd-0159-1000-45a7-8306c28f2786",
        "parentGroupId": "cbe6e53b-0158-1000-e36a-f9d26bb1b510",
        "source": {
            "id": "dcbea89f-0159-1000-278c-cc38bab689bf",
            "type": "PROCESSOR",
            "groupId": "cbe6e53b-0158-1000-e36a-f9d26bb1b510",
            "name": "GenerateFlowFile",
            "running": false,
            "comments": ""
        },
        "destination": {
            "id": "dcbebd86-0159-1000-7559-d77d1e05c910",
            "type": "PROCESSOR",
            "groupId": "cbe6e53b-0158-1000-e36a-f9d26bb1b510",
            "name": "PutFile",
            "running": false,
            "comments": ""
        },
        "name": "",
        "labelIndex": 1,
        "zIndex": 0,
        "selectedRelationships": ["success"],
        "availableRelationships": ["success"],
        "backPressureObjectThreshold": 10000,
        "backPressureDataSizeThreshold": "1 GB",
        "flowFileExpiration": "0 sec",
        "prioritizers": [],
        "bends": []
    },
    "status": {
        "id": "dcbee9dd-0159-1000-45a7-8306c28f2786",
        "groupId": "cbe6e53b-0158-1000-e36a-f9d26bb1b510",
        "name": "success",
        "statsLastRefreshed": "09:02:22 EST",
        "sourceId": "dcbea89f-0159-1000-278c-cc38bab689bf",
        "sourceName": "GenerateFlowFile",
        "destinationId": "dcbebd86-0159-1000-7559-d77d1e05c910",
        "destinationName": "PutFile",
        "aggregateSnapshot": {
            "id": "dcbee9dd-0159-1000-45a7-8306c28f2786",
            "groupId": "cbe6e53b-0158-1000-e36a-f9d26bb1b510",
            "name": "success",
            "sourceName": "GenerateFlowFile",
            "destinationName": "PutFile",
            "flowFilesIn": 0,
            "bytesIn": 0,
            "input": "0 (0 bytes)",
            "flowFilesOut": 0,
            "bytesOut": 0,
            "output": "0 (0 bytes)",
            "flowFilesQueued": 18,
            "bytesQueued": 18,
            "queued": "18 (18 bytes)",
            "queuedSize": "18 bytes",
            "queuedCount": "18"
        }
    },
    "bends": [],
    "labelIndex": 1,
    "zIndex": 0,
    "sourceId": "dcbea89f-0159-1000-278c-cc38bab689bf",
    "sourceGroupId": "cbe6e53b-0158-1000-e36a-f9d26bb1b510",
    "sourceType": "PROCESSOR",
    "destinationId": "dcbebd86-0159-1000-7559-d77d1e05c910",
    "destinationGroupId": "cbe6e53b-0158-1000-e36a-f9d26bb1b510",
    "destinationType": "PROCESSOR"
}' http://localhost:8080/nifi-api/connections/dcbee9dd-0159-1000-45a7-8306c28f2786

2) Once you execute the above, if the update is successful, you will get below result:

HTTP/1.1 200 OK
Date: Fri, 27 Jan 2017 14:59:37 GMT
Cache-Control: private, no-cache, no-store, no-transform
Content-Type: application/json
Transfer-Encoding: chunked
Server: Jetty(9.3.9.v20160517)

Result will be similar as below:

12502-curl-result.jpg

3) Now login Back to the NiFi UI and make sure the change is done:

12501-data-flow-after.jpg

References:

• NiFi API
• My github

Thanks,

Jobin George

[#2]

Hi Jobin,

Thanks for the post.I am doing same exactly what you did but i am getting error

NIFI flows
108702-nifi-processors.png

Curl Command

108712-curl-command.png

*****Proccessors UUID*****

putNext UUID---->

b0971f42-016a-1000-ea25-30e14e18c4ea

generateflow UUID------>

b094e512-016a-1000-7e53-e5b4570d3a52

connection UUID---->

b096684f-016a-1000-fe11-3d8b80583b38

Note: I am doing this in windows PC locally.

Please help here

[#3]

Thank you for the article. 

In my case, we need to create a new connection between two process groups. Is the same curl changing parameters?

Thank you advanced.