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README.md

Fluvio Client Node Examples

Prerequisites

Before running the examples, you'll need to have completed the following:

  • Install Node.js (v16.11.0 or above)
  • Have the Fluvio CLI installed. Node API uses the profile installed by Fluvio CLI to connect to the cluster.
    • Update existing Fluvio CLI with fluvio update.
  • Have access to a Fluvio cluster.

Create a Node Project

In the examples directory, create a node project and install the following libraries:

npm init -y
npm install -D typescript ts-node @types/node
npm install -S @fluvio/client

Note: Fluvio is installed from npm rather than called locally.

Examples

All examples run with:

npx ts-node ./<name-of-example>.ts

API summary

Create Topic

Create topic node-examples:

% npx ts-node ./createTopic.ts  

connecting client to sc
topic 'node-examples' created

Use fluvio CLI to check:

% fluvio topic list

Find Topic

Check if topic node-examples exists:

% npx ts-node ./findTopic.ts

connecting client to fluvio
topic:  {
  "name": "node-examples",
  "spec": {
    "replicas": {
      "computed": {
        "partitions": 1,
        "replicationFactor": 1,
        "ignoreRackAssignment": false
      }
    },
    "cleanupPolicy": null,
    "storage": null
  },
  "status": {
    "resolution": "Provisioned",
    "replicaMap": {
      "0": [
        0
      ]
    },
    "reason": ""
  }
}

Returns null if topic does not exist.

List Topics

List all topics:

% npx ts-node ./listTopic.ts

connecting client to fluvio
topics:  [
  {
    "name": "node-examples",
    "spec": {
      "replicas": {
        "computed": {
          "partitions": 1,
          "replicationFactor": 1,
          "ignoreRackAssignment": false
        }
      },
      "cleanupPolicy": null,
      "storage": null
    },
    "status": {
      "resolution": "Provisioned",
      "replicaMap": {
        "0": [
          0
        ]
      },
      "reason": ""
    }
  }
]

Delete Topic

Delete topic node-examples:

% npx ts-node ./deleteTopic.ts 

connecting client to fluvio
topic 'node-examples' deleted

Produce

Produce 10 records to node-example topic.

% npx ts-node ./produce.ts

connecting client to fluvio
{"key":1,"message":"Value 1"}
{"key":2,"message":"Value 2"}
{"key":3,"message":"Value 3"}
{"key":4,"message":"Value 4"}
{"key":5,"message":"Value 5"}
{"key":6,"message":"Value 6"}
{"key":7,"message":"Value 7"}
{"key":8,"message":"Value 8"}
{"key":9,"message":"Value 9"}
{"key":10,"message":"Value 10"}

The producer example shows 2 API variants, one with key and the other without.

Produce Batch

Produce 10 records to node-example topic using batching. Batching small packets can significantly improve performance.

% npx ts-node ./produceBatch.ts

connecting client to fluvio
[
  [
    Uint8Array(5) [ 75, 69, 89, 32, 49 ],
    '{"key":1,"message":"Message 1"}'
  ],
  [
    Uint8Array(5) [ 75, 69, 89, 32, 50 ],
    '{"key":2,"message":"Message 2"}'
  ],
  ...
]

Checkout the sendAll API for additional details.

Consume

Consume all records stored in node-example:

% npx ts-node ./consume.ts

connecting client to fluvio
read from beginning
Key=KEY 1, Value={"key":1,"message":"Value 1"}
Key=KEY 2, Value={"key":2,"message":"Value 2"}
Key=KEY 3, Value={"key":3,"message":"Value 3"}
Key=KEY 4, Value={"key":4,"message":"Value 4"}
Key=KEY 5, Value={"key":5,"message":"Value 5"}
Key=KEY 6, Value={"key":6,"message":"Value 6"}
Key=KEY 7, Value={"key":7,"message":"Value 7"}
Key=KEY 8, Value={"key":8,"message":"Value 8"}
Key=KEY 9, Value={"key":9,"message":"Value 9"}
Key=KEY 10, Value={"key":10,"message":"Value 10"}
^C

The consume reads all records from the beginning of list, then waits for new records. The offset controls the location of the pointer in the list. Checkout the API for additional settings.

Consume Iterator

As opposed to the previous Consume API, the iterator variant reads to completion. The API stops reading when it reches the end of the list.

% npx ts-node ./consumeIterator.ts

connecting client to fluvio
read from node-examples
Key=KEY 1, value={"key":1,"message":"Value 1"}
Key=KEY 2, value={"key":2,"message":"Value 2"}
Key=KEY 3, value={"key":3,"message":"Value 3"}
Key=KEY 4, value={"key":4,"message":"Value 4"}
Key=KEY 5, value={"key":5,"message":"Value 5"}
Key=KEY 6, value={"key":6,"message":"Value 6"}
Key=KEY 7, value={"key":7,"message":"Value 7"}
Key=KEY 8, value={"key":8,"message":"Value 8"}
Key=KEY 9, value={"key":9,"message":"Value 9"}
Key=KEY 10, value={"key":10,"message":"Value 10"}

Note, in this example the API retrieves both keys and values.

Other references