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Following a conversation, last week, started about the implementation of the load balancing of HIVE nodes depending on the user's geolocation, I thought it would be nice to share with the HIVE developer community a Typescript service I made and use in some of my applications (Backend & Frontend).

After a few days to extract my service and transform it into an installable package (what I am not used to) I can finally give you the HIVE Nodes Checker.

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HIVE nodes checker

Regularly checks availability and performance of HIVE blockchain RPC nodes asynchronously, stores/updates the result in an in-memory array, and sends the result through a subscription (RxJS).

Two modes

Lightweight mode

In this mode, only one call to the condenser_api.get_config method is made on each node, The version executed on the node is retrieved and the response time is calculated by hrtime.

The message sent by RxJS is:

[{
  "url": string
  "nb_ok": number
  "nb_error": number
  "error"?: string
  "last_check": number
  "status": "unkown"|"online"|"degraded"|"error"
  "duration"?: number
  "average_time"?: number
  "version"?: string
  "deactivated"?: boolean

  "test_result":   []
}]

nb_ok and nb_error are incremented each time, allowing you to calculate an efficiency rate.

Full mode

In this case the methods below are checked:

condenser_api.get_config
condenser_api.get_dynamic_global_properties
condenser_api.get_block
condenser_api.get_accounts
condenser_api.get_account_history
bridge.get_post
bridge.get_account_posts

The version executed on the node is retrieved, the response time is calculated by hrtime and an average answer time is calculated.

The message sent by RxJS is:

[{
  "url": string
  "nb_ok": number
  "nb_error": number
  "error"?: string
  "last_check": number
  "status": "unkown"|"online"|"degraded"|"error"
  "duration"?: number
  "average_time"?: number
  "version"?: string
  "deactivated"?: boolean

  "test_result":   [{
    "name": string
    "description": string
    "method": string
    "success": boolean
    "duration": number
    "error"?: string
    "last_check": number
  }]
}]

Params

• url: array of node url to check
• options (optional):
  • full (boolean): if false perform only a get_config with response time (default: false)
  • interval (seconds): delay in seconds between each execution (default: 900 seconds)
  • timeout (seconds): timeout in seconds for node request (default: 3 seconds)

Example usage

Performing a full checking:

import { HiveNodesChecker } from '@mintrawa/hive-nodes-checker'

/** HIVE nodes url to check */
const nodes = [
  "https://api.hive.blog",
  "https://api.openhive.network",
  "https://api.deathwing.me",
  "https://rpc.ausbit.dev",
  "https://rpc.ecency.com",
  "https://hive-api.arcange.eu",
]

/** Options */
const options = {
  full: true,
  interval: 600 // 10 minutes
}
/** Init the checker */
const nodesChecker = new HiveNodesChecker(nodes, options)
/** Start the checker */
nodesChecker.start()
/** Subscribe results */
nodesChecker.message.subscribe({
  next: async m => {
    console.log('=====> NEW MESSAGE', m)
    console.log()
  },
  error: error => {
    console.log('=====> ERROR MESSAGE')
    console.log(error)
    console.log()
  }
})  

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Github: https://github.com/Mintrawa/hive-nodes-checker
NPM: https://www.npmjs.com/package/@mintrawa/hive-nodes-checker

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_{Tested in NodeJS v16.13.1 with a Raspberry PI3 1Gb
Tested in Angular v13.1.1
Tested in Chrome browser (HTML with the minified version)}

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_{Original photo by Lars Kienle on Unsplash}

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PRINCIPAL	BACKUP/SEED
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