server/lib/requestsScheduler.js

   1 'use strict'
   2
   3 const async = require('async')
   4 const map = require('lodash/map')
   5
   6 const constants = require('../initializers/constants')
   7 const logger = require('../helpers/logger')
   8 const Pods = require('../models/pods')
   9 const Requests = require('../models/requests')
  10 const requests = require('../helpers/requests')
  11 const videos = require('../lib/videos')
  12 const Videos = require('../models/videos')
  13
  14 let timer = null
  15
  16 const requestsScheduler = {
  17   activate: activate,
  18   addRequest: addRequest,
  19   addRequestTo: addRequestTo,
  20   deactivate: deactivate,
  21   flush: flush,
  22   forceSend: forceSend
  23 }
  24
  25 function activate () {
  26   logger.info('Requests scheduler activated.')
  27   timer = setInterval(makeRequests, constants.INTERVAL)
  28 }
  29
  30 // Add request to the scheduler
  31 function addRequest (type, data) {
  32   logger.debug('Add request of type %s to the requests scheduler.', type, { data: data })
  33
  34   const request = {
  35     type: type,
  36     data: data
  37   }
  38
  39   Pods.listAllIds(function (err, podIds) {
  40     if (err) {
  41       logger.debug('Cannot list pod ids.')
  42       return
  43     }
  44
  45     // No friends
  46     if (!podIds) return
  47
  48     Requests.create(request, podIds, function (err) {
  49       if (err) logger.error('Cannot create a request.', { error: err })
  50     })
  51   })
  52 }
  53
  54 function addRequestTo (podIds, type, data) {
  55   const request = {
  56     type: type,
  57     data: data
  58   }
  59
  60   Requests.create(request, podIds, function (err) {
  61     if (err) logger.error('Cannot create a request.', { error: err })
  62   })
  63 }
  64
  65 function deactivate () {
  66   logger.info('Requests scheduler deactivated.')
  67   clearInterval(timer)
  68 }
  69
  70 function flush () {
  71   Requests.removeAll(function (err) {
  72     if (err) {
  73       logger.error('Cannot flush the requests.', { error: err })
  74     }
  75   })
  76 }
  77
  78 function forceSend () {
  79   logger.info('Force requests scheduler sending.')
  80   makeRequests()
  81 }
  82
  83 // ---------------------------------------------------------------------------
  84
  85 module.exports = requestsScheduler
  86
  87 // ---------------------------------------------------------------------------
  88
  89 // Make a requests to friends of a certain type
  90 function makeRequest (toPod, requestsToMake, callback) {
  91   if (!callback) callback = function () {}
  92
  93   const params = {
  94     toPod: toPod,
  95     encrypt: true, // Security
  96     sign: true, // To prove our identity
  97     method: 'POST',
  98     path: '/api/' + constants.API_VERSION + '/remote/videos',
  99     data: requestsToMake // Requests we need to make
 100   }
 101
 102   // Make multiple retry requests to all of pods
 103   // The function fire some useful callbacks
 104   requests.makeSecureRequest(params, function (err, res) {
 105     if (err || (res.statusCode !== 200 && res.statusCode !== 201 && res.statusCode !== 204)) {
 106       logger.error('Error sending secure request to %s pod.', toPod.url, { error: err || new Error('Status code not 20x') })
 107
 108       return callback(false)
 109     }
 110
 111     return callback(true)
 112   })
 113 }
 114
 115 // Make all the requests of the scheduler
 116 function makeRequests () {
 117   Requests.list(function (err, requests) {
 118     if (err) {
 119       logger.error('Cannot get the list of requests.', { err: err })
 120       return // Abort
 121     }
 122
 123     // If there are no requests, abort
 124     if (requests.length === 0) {
 125       logger.info('No requests to make.')
 126       return
 127     }
 128
 129     logger.info('Making requests to friends.')
 130
 131     // Requests by pods id
 132     const requestsToMake = {}
 133
 134     requests.forEach(function (poolRequest) {
 135       poolRequest.to.forEach(function (toPodId) {
 136         if (!requestsToMake[toPodId]) {
 137           requestsToMake[toPodId] = {
 138             ids: [],
 139             datas: []
 140           }
 141         }
 142
 143         requestsToMake[toPodId].ids.push(poolRequest._id)
 144         requestsToMake[toPodId].datas.push(poolRequest.request)
 145       })
 146     })
 147
 148     const goodPods = []
 149     const badPods = []
 150
 151     async.eachLimit(Object.keys(requestsToMake), constants.REQUESTS_IN_PARALLEL, function (toPodId, callbackEach) {
 152       const requestToMake = requestsToMake[toPodId]
 153
 154       // FIXME: mongodb request inside a loop :/
 155       Pods.findById(toPodId, function (err, toPod) {
 156         if (err) return logger.error('Error finding pod by id.', { err: err })
 157
 158         // Maybe the pod is not our friend anymore so simply remove them
 159         if (!toPod) {
 160           Requests.removePodOf(requestToMake.ids, toPodId)
 161           return callbackEach()
 162         }
 163
 164         makeRequest(toPod, requestToMake.datas, function (success) {
 165           if (err) {
 166             logger.error('Errors when sent request to %s.', toPod.url, { error: err })
 167             // Do not stop the process just for one error
 168             return callbackEach()
 169           }
 170
 171           if (success === true) {
 172             logger.debug('Removing requests for %s pod.', toPodId, { requestsIds: requestToMake.ids })
 173
 174             // Remove the pod id of these request ids
 175             Requests.removePodOf(requestToMake.ids, toPodId)
 176             goodPods.push(toPodId)
 177           } else {
 178             badPods.push(toPodId)
 179           }
 180
 181           callbackEach()
 182         })
 183       })
 184     }, function () {
 185       // All the requests were made, we update the pods score
 186       updatePodsScore(goodPods, badPods)
 187       // Flush requests with no pod
 188       Requests.removeWithEmptyTo()
 189     })
 190   })
 191 }
 192
 193 // Remove pods with a score of 0 (too many requests where they were unreachable)
 194 function removeBadPods () {
 195   async.waterfall([
 196     function findBadPods (callback) {
 197       Pods.findBadPods(function (err, pods) {
 198         if (err) {
 199           logger.error('Cannot find bad pods.', { error: err })
 200           return callback(err)
 201         }
 202
 203         return callback(null, pods)
 204       })
 205     },
 206
 207     function listVideosOfTheseBadPods (pods, callback) {
 208       if (pods.length === 0) return callback(null)
 209
 210       const urls = map(pods, 'url')
 211       const ids = map(pods, '_id')
 212
 213       Videos.listFromUrls(urls, function (err, videosList) {
 214         if (err) {
 215           logger.error('Cannot list videos urls.', { error: err, urls: urls })
 216           return callback(null, ids, [])
 217         }
 218
 219         return callback(null, ids, videosList)
 220       })
 221     },
 222
 223     function removeVideosOfTheseBadPods (podIds, videosList, callback) {
 224       // We don't have to remove pods, skip
 225       if (typeof podIds === 'function') return podIds(null)
 226
 227       // Remove the remote videos
 228       videos.removeRemoteVideos(videosList, function (err) {
 229         if (err) logger.error('Cannot remove remote videos.', { error: err })
 230
 231         return callback(null, podIds)
 232       })
 233     },
 234
 235     function removeBadPodsFromDB (podIds, callback) {
 236       // We don't have to remove pods, skip
 237       if (typeof podIds === 'function') return podIds(null)
 238
 239       Pods.removeAllByIds(podIds, callback)
 240     }
 241   ], function (err, removeResult) {
 242     if (err) {
 243       logger.error('Cannot remove bad pods.', { error: err })
 244     } else if (removeResult) {
 245       const podsRemoved = removeResult.result.n
 246       logger.info('Removed %d pods.', podsRemoved)
 247     } else {
 248       logger.info('No need to remove bad pods.')
 249     }
 250   })
 251 }
 252
 253 function updatePodsScore (goodPods, badPods) {
 254   logger.info('Updating %d good pods and %d bad pods scores.', goodPods.length, badPods.length)
 255
 256   Pods.incrementScores(goodPods, constants.PODS_SCORE.BONUS, function (err) {
 257     if (err) logger.error('Cannot increment scores of good pods.')
 258   })
 259
 260   Pods.incrementScores(badPods, constants.PODS_SCORE.MALUS, function (err) {
 261     if (err) logger.error('Cannot decrement scores of bad pods.')
 262     removeBadPods()
 263   })
 264 }