dbstats.js

// Utilitary script to get stats on all collections and indexes of a mongo cluster
//
// Usage:
// cat dbstats.js | mongosh MONGO_URI | sed -n 's/^>>:*//p'
// curl -L https://gist.githubusercontent.com/balthazar/e2047bdc23cd077ed7c91310f44552f0/raw | mongosh MONGO_URI | sed -n 's/^>>:*//p'

const mgo = db.getMongo()
const byteUnits = ['KB', 'MB', 'GB', 'TB', 'PB', 'EB', 'ZB', 'YB']

const RED = '\033[0;31m'
const BLUE = '\033[0;34m'
const GREEN = '\033[0;32m'
const YELLOW = '\033[0;33m'
const MAGENTA = '\033[0;35m'
const CYAN = '\033[0;36m'
const NC = '\033[0m'

function p(txt) {
  txt.split('\n').map(t => print(`>>${t}`))
}

function humanSize(bytes) {
  let i = -1
  while (bytes > 1024) {
    bytes = bytes / 1024
    ++i
  }

  return `${Math.max(bytes, 0.1).toLocaleString(undefined, { maximumFractionDigits: 2 })} ${
    byteUnits[i] || 'B'
  }`
}

function getStats(name) {
  const db = mgo.getDB(name)
  const stats = db
    .getCollectionNames()
    .map(n => db.getCollection(n).stats())
    .sort((a, b) => a.size - b.size)

  let total = 0

  print(stats[0])

  for (const stat of stats) {
    const colName = stat.ns.replace(`${name}.`, '')
    if (colName.startsWith('system.')) continue

    p(`${GREEN}${colName} ${humanSize(stat.totalSize)}${NC}`)
    p(`${MAGENTA}Data ${humanSize(stat.storageSize)}${NC}`)

    p(`${BLUE}Indexes${NC} ${humanSize(stat.totalIndexSize)}`)
    total += Number(stat.storageSize)
    for (const index in stat.indexSizes) {
      const iSize = stat.indexSizes[index]
      p(`${BLUE}${index}${NC} ${humanSize(iSize)}`)
      total += Number(iSize)
    }

    p(`${YELLOW}${stat.wiredTiger.uri.replace('statistics:table:', '')}${NC}`)

    p('')
  }

  const { fsUsedSize } = db.stats()
  const diffFs = fsUsedSize - total
  const diffTxt = `${YELLOW}FS ${humanSize(fsUsedSize)}${NC} (${humanSize(diffFs)} diff)`

  p(`${CYAN}${name}${NC}`)
  p(`${RED}Total ${humanSize(total)}${NC}`)
  if (diffFs) p(diffTxt)
}

;(() => {
  const dbs = mgo.getDBNames().filter(n => !n.match(/^(config|local|admin)$/))

  for (const name of dbs) {
    p(name !== dbs[0] ? '\n\n=======\n' : '\n')
    getStats(name)
  }
})()