Nebula Nodejs SDK

This repository provides Nebula client API in Nodejs.

Features

• Muti-Server Support

• Auto-reconnection support

  Client will try to reconnect forever, until the server is available again.

• Connection pool support

• Disconnection detection

  A heartbeat mechanism is implemented, client will send ping to server each pingInterval ms for detect connective

• Thrift enhancement

  fix auto reconnect issue#2407

  fix performance issue in huge data scene#2483

API

Connection Options

| parameter | type | description | | -------------- | -------- | ------------------------------------------------------------------------------- | | servers | string[] | nebula servers | | userName | string | username for login | | password | string | password for login | | space | string | space name in nebula server | | poolSize | number | Pool size for each server(Optional, default：5) | | bufferSize | number | Command cache in offline or before established connect (Optional, defaul: 2000) | | executeTimeout | number | Command executing timeout in ms (Optional, default：10000) | | pingInterval | number | for keepalive, ping duration in ms, (Optional, default：60000） |

How To

Install

For compiling C++ native module, node-gyp is required, you can install node-gyp by npm install -g node-gyp

npm install @nebula-contrib/nebula-nodejs --save --unsafe-perm

Simple and convenient API

// ESM
import { createClient } from '@nebula-contrib/nebula-nodejs'

// CommonJS
// const { createClient } = require('@nebula-contrib/nebula-nodejs')

// Connection Options
const options = {
  servers: ['ip-1:port','ip-2:port'],
  userName: 'xxx',
  password: 'xxx',
  space: 'space name',
  poolSize: 5,
  bufferSize: 2000,
  executeTimeout: 15000,
  pingInterval: 60000
}

// Create client
const client = createClient(options)

// Execute command
// 1. return parsed data (recommend)
const response = await client.execute('GET SUBGRAPH 3 STEPS FROM -7897618527020261406')
// 2. return nebula original data
const responseOriginal = await client.execute('GET SUBGRAPH 3 STEPS FROM -7897618527020261406', true)

Events

| parameter | description | | ----------------- | -------------------------------------------- | | sender | the individual connection in connection pool | | error | Nebula Error | | retryInfo | Retry information | | retryInfo.delay | delay time | | retryInfo.attempt | total attempts |

const client = createClient(options)

// connection is ready for executing command
client.on('ready', ({sender}) => {

})

// error occurs
client.on('error', ({ sender, error }) => {

})

// connected event
client.on('connected', ({ sender }) => {

})

// authorized successfully
client.on('authorized', ({ sender }) => {

})

// reconnecting
client.on('reconnecting', ({ sender, retryInfo }) => {

})

// closed
client.on('close', { sender }) => {

}

About hash64 function

nebula-nodejs exports hash64 function for converting string to string[], it's based on MurmurHash3.

// ESM
import { hash64 } from '@nebula-contrib/nebula-nodejs'

// CommonJS
// const { hash64 } = require('@nebula-contrib/nebula-nodejs')

const results = hash64('f10011b64aa4e7503cd45a7fdc24387b')

console.log(results)

// Output:
// ['2852836996923339651', '-6853534673140605817']

About Int64

nodejs cannot repreent Int64, so we convert Int64 bytes to string

// ESM
import { bytesToLongLongString } from '@nebula-contrib/nebula-nodejs'

// CommonJS
// const { bytesToLongLongString } = require('@nebula-contrib/nebula-nodejs')

const s = '-7897618527020261406'

const buffer = [146, 102, 5, 203, 5, 105, 223, 226]
const result = bytesToLongLongString(buffer)

// result equals s

Development

Build

git clone https://github.com/nebula-contrib/nebula-node.git
cd nebula-node
npm install --unsafe-perm
npm run build

Unit Test

npm run build
npm run test

Unit Test Coverage

npm run coverage

Publish

npm run build
cd dist
npm publish

TODO

Not implemented data type for auto parser

| Data Type | property name in nebula response | | --------- | -------------------------------- | | DataSet | gVal | | Geography | ggVal | | Duration | duVal |

Released Versions in npmjs.com

| NodeJS Client Version | Nebula Graph Version | | --------------------- | --------------------- | | 2.6.2 | 2.6.x | | 3.0.2 | 3.x |