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
3.0.3	3.x