Improve redundancy: add 'min_lifetime' configuration

27 files changed, 627 insertions, 278 deletions

diff --git a/config/default.yaml b/config/default.yaml
index fa1fb628a..0d7d948c2 100644
--- a/config/default.yaml
+++ b/config/default.yaml
@@ -75,14 +75,20 @@ redundancy:
     strategies:
 #      -
 #        size: '10GB'
+#        # Minimum time the video must remain in the cache. Only accept values > 10 hours (to not overload remote instances)
+#        min_lifetime: '48 hours'
 #        strategy: 'most-views' # Cache videos that have the most views
 #      -
 #        size: '10GB'
+#        # Minimum time the video must remain in the cache. Only accept values > 10 hours (to not overload remote instances)
+#        min_lifetime: '48 hours'
 #        strategy: 'trending' # Cache trending videos
 #      -
 #        size: '10GB'
+#        # Minimum time the video must remain in the cache. Only accept values > 10 hours (to not overload remote instances)
+#        min_lifetime: '48 hours'
 #        strategy: 'recently-added' # Cache recently added videos
-#        minViews: 10 # Having at least x views
+#        min_views: 10 # Having at least x views
 
 cache:
   previews:
diff --git a/config/production.yaml.example b/config/production.yaml.example
index 4d8752206..f9da8e0dd 100644
--- a/config/production.yaml.example
+++ b/config/production.yaml.example
@@ -76,14 +76,20 @@ redundancy:
     strategies:
 #      -
 #        size: '10GB'
+#        # Minimum time the video must remain in the cache. Only accept values > 10 hours (to not overload remote instances)
+#        min_lifetime: '48 hours'
 #        strategy: 'most-views' # Cache videos that have the most views
 #      -
 #        size: '10GB'
+#        # Minimum time the video must remain in the cache. Only accept values > 10 hours (to not overload remote instances)
+#        min_lifetime: '48 hours'
 #        strategy: 'trending' # Cache trending videos
 #      -
 #        size: '10GB'
+#        # Minimum time the video must remain in the cache. Only accept values > 10 hours (to not overload remote instances)
+#        min_lifetime: '48 hours'
 #        strategy: 'recently-added' # Cache recently added videos
-#        minViews: 10 # Having at least x views
+#        min_views: 10 # Having at least x views
 
 ###############################################################################
 #
diff --git a/config/test.yaml b/config/test.yaml
index ad94b00cd..04c999966 100644
--- a/config/test.yaml
+++ b/config/test.yaml
@@ -23,18 +23,21 @@ log:
 
 redundancy:
   videos:
-    check_interval: '5 seconds'
+    check_interval: '10 minutes'
     strategies:
       -
         size: '10MB'
+        min_lifetime: '10 minutes'
         strategy: 'most-views'
       -
         size: '10MB'
+        min_lifetime: '10 minutes'
         strategy: 'trending'
       -
         size: '10MB'
+        min_lifetime: '10 minutes'
         strategy: 'recently-added'
-        minViews: 1
+        min_views: 1
 
 cache:
   previews:
diff --git a/server.ts b/server.ts
index 8bc5e5f32..59fb820b4 100644
--- a/server.ts
+++ b/server.ts
@@ -1,6 +1,4 @@
 // FIXME: https://github.com/nodejs/node/pull/16853
-import { VideosCaptionCache } from './server/lib/cache/videos-caption-cache'
-
 require('tls').DEFAULT_ECDH_CURVE = 'auto'
 
 import { isTestInstance } from './server/helpers/core-utils'
@@ -17,7 +15,7 @@ import * as cors from 'cors'
 import * as cookieParser from 'cookie-parser'
 import * as helmet from 'helmet'
 import * as useragent from 'useragent'
-import * as anonymise from 'ip-anonymize'
+import * as anonymize from 'ip-anonymize'
 
 process.title = 'peertube'
 
@@ -25,7 +23,7 @@ process.title = 'peertube'
 const app = express()
 
 // ----------- Core checker -----------
-import { checkMissedConfig, checkFFmpeg, checkConfig, checkActivityPubUrls } from './server/initializers/checker'
+import { checkMissedConfig, checkFFmpeg } from './server/initializers/checker-before-init'
 
 // Do not use barrels because we don't want to load all modules here (we need to initialize database first)
 import { logger } from './server/helpers/logger'
@@ -43,6 +41,8 @@ checkFFmpeg(CONFIG)
     process.exit(-1)
   })
 
+import { checkConfig, checkActivityPubUrls } from './server/initializers/checker-after-init'
+
 const errorMessage = checkConfig()
 if (errorMessage !== null) {
   throw new Error(errorMessage)
@@ -76,7 +76,7 @@ migrate()
 import { installApplication } from './server/initializers'
 import { Emailer } from './server/lib/emailer'
 import { JobQueue } from './server/lib/job-queue'
-import { VideosPreviewCache } from './server/lib/cache'
+import { VideosPreviewCache, VideosCaptionCache } from './server/lib/cache'
 import {
   activityPubRouter,
   apiRouter,
@@ -111,7 +111,7 @@ if (isTestInstance()) {
 // For the logger
 morgan.token('remote-addr', req => {
   return (req.get('DNT') === '1') ?
-    anonymise(req.ip || (req.connection && req.connection.remoteAddress) || undefined,
+    anonymize(req.ip || (req.connection && req.connection.remoteAddress) || undefined,
     16, // bitmask for IPv4
     16  // bitmask for IPv6
     ) :
diff --git a/server/helpers/ffmpeg-utils.ts b/server/helpers/ffmpeg-utils.ts
index 7c45f3632..22bc25476 100644
--- a/server/helpers/ffmpeg-utils.ts
+++ b/server/helpers/ffmpeg-utils.ts
@@ -4,7 +4,7 @@ import { VideoResolution } from '../../shared/models/videos'
 import { CONFIG, FFMPEG_NICE, VIDEO_TRANSCODING_FPS } from '../initializers'
 import { processImage } from './image-utils'
 import { logger } from './logger'
-import { checkFFmpegEncoders } from '../initializers/checker'
+import { checkFFmpegEncoders } from '../initializers/checker-before-init'
 import { remove } from 'fs-extra'
 
 function computeResolutionsToTranscode (videoFileHeight: number) {
diff --git a/server/initializers/checker-after-init.ts b/server/initializers/checker-after-init.ts
new file mode 100644
index 000000000..588526235
--- /dev/null
+++ b/server/initializers/checker-after-init.ts
@@ -0,0 +1,115 @@
+import * as config from 'config'
+import { promisify0, isProdInstance, parseDuration, isTestInstance } from '../helpers/core-utils'
+import { UserModel } from '../models/account/user'
+import { ApplicationModel } from '../models/application/application'
+import { OAuthClientModel } from '../models/oauth/oauth-client'
+import { parse } from 'url'
+import { CONFIG } from './constants'
+import { logger } from '../helpers/logger'
+import { getServerActor } from '../helpers/utils'
+import { RecentlyAddedStrategy, VideosRedundancy } from '../../shared/models/redundancy'
+import { isArray } from '../helpers/custom-validators/misc'
+import { uniq } from 'lodash'
+
+async function checkActivityPubUrls () {
+  const actor = await getServerActor()
+
+  const parsed = parse(actor.url)
+  if (CONFIG.WEBSERVER.HOST !== parsed.host) {
+    const NODE_ENV = config.util.getEnv('NODE_ENV')
+    const NODE_CONFIG_DIR = config.util.getEnv('NODE_CONFIG_DIR')
+
+    logger.warn(
+      'It seems PeerTube was started (and created some data) with another domain name. ' +
+      'This means you will not be able to federate! ' +
+      'Please use %s %s npm run update-host to fix this.',
+      NODE_CONFIG_DIR ? `NODE_CONFIG_DIR=${NODE_CONFIG_DIR}` : '',
+      NODE_ENV ? `NODE_ENV=${NODE_ENV}` : ''
+    )
+  }
+}
+
+// Some checks on configuration files
+// Return an error message, or null if everything is okay
+function checkConfig () {
+  const defaultNSFWPolicy = CONFIG.INSTANCE.DEFAULT_NSFW_POLICY
+
+  // NSFW policy
+  {
+    const available = [ 'do_not_list', 'blur', 'display' ]
+    if (available.indexOf(defaultNSFWPolicy) === -1) {
+      return 'NSFW policy setting should be ' + available.join(' or ') + ' instead of ' + defaultNSFWPolicy
+    }
+  }
+
+  // Redundancies
+  const redundancyVideos = CONFIG.REDUNDANCY.VIDEOS.STRATEGIES
+  if (isArray(redundancyVideos)) {
+    const available = [ 'most-views', 'trending', 'recently-added' ]
+    for (const r of redundancyVideos) {
+      if (available.indexOf(r.strategy) === -1) {
+        return 'Videos redundancy should have ' + available.join(' or ') + ' strategy instead of ' + r.strategy
+      }
+
+      // Lifetime should not be < 10 hours
+      if (!isTestInstance() && r.minLifetime < 1000 * 3600 * 10) {
+        return 'Video redundancy minimum lifetime should be >= 10 hours for strategy ' + r.strategy
+      }
+    }
+
+    const filtered = uniq(redundancyVideos.map(r => r.strategy))
+    if (filtered.length !== redundancyVideos.length) {
+      return 'Redundancy video entries should have unique strategies'
+    }
+
+    const recentlyAddedStrategy = redundancyVideos.find(r => r.strategy === 'recently-added') as RecentlyAddedStrategy
+    if (recentlyAddedStrategy && isNaN(recentlyAddedStrategy.minViews)) {
+      return 'Min views in recently added strategy is not a number'
+    }
+  }
+
+  if (isProdInstance()) {
+    const configStorage = config.get('storage')
+    for (const key of Object.keys(configStorage)) {
+      if (configStorage[key].startsWith('storage/')) {
+        logger.warn(
+          'Directory of %s should not be in the production directory of PeerTube. Please check your production configuration file.',
+          key
+        )
+      }
+    }
+  }
+
+  return null
+}
+
+// We get db by param to not import it in this file (import orders)
+async function clientsExist () {
+  const totalClients = await OAuthClientModel.countTotal()
+
+  return totalClients !== 0
+}
+
+// We get db by param to not import it in this file (import orders)
+async function usersExist () {
+  const totalUsers = await UserModel.countTotal()
+
+  return totalUsers !== 0
+}
+
+// We get db by param to not import it in this file (import orders)
+async function applicationExist () {
+  const totalApplication = await ApplicationModel.countTotal()
+
+  return totalApplication !== 0
+}
+
+// ---------------------------------------------------------------------------
+
+export {
+  checkConfig,
+  clientsExist,
+  usersExist,
+  applicationExist,
+  checkActivityPubUrls
+}
diff --git a/server/initializers/checker.ts b/server/initializers/checker-before-init.ts
index 5b068caa1..4f46d406a 100644
--- a/server/initializers/checker.ts
+++ b/server/initializers/checker-before-init.ts
@@ -1,78 +1,8 @@
 import * as config from 'config'
-import { promisify0, isProdInstance } from '../helpers/core-utils'
-import { UserModel } from '../models/account/user'
-import { ApplicationModel } from '../models/application/application'
-import { OAuthClientModel } from '../models/oauth/oauth-client'
-import { parse } from 'url'
-import { CONFIG } from './constants'
-import { logger } from '../helpers/logger'
-import { getServerActor } from '../helpers/utils'
-import { RecentlyAddedStrategy, VideosRedundancy } from '../../shared/models/redundancy'
+import { promisify0 } from '../helpers/core-utils'
 import { isArray } from '../helpers/custom-validators/misc'
-import { uniq } from 'lodash'
-
-async function checkActivityPubUrls () {
-  const actor = await getServerActor()
-
-  const parsed = parse(actor.url)
-  if (CONFIG.WEBSERVER.HOST !== parsed.host) {
-    const NODE_ENV = config.util.getEnv('NODE_ENV')
-    const NODE_CONFIG_DIR = config.util.getEnv('NODE_CONFIG_DIR')
-
-    logger.warn(
-      'It seems PeerTube was started (and created some data) with another domain name. ' +
-      'This means you will not be able to federate! ' +
-      'Please use %s %s npm run update-host to fix this.',
-      NODE_CONFIG_DIR ? `NODE_CONFIG_DIR=${NODE_CONFIG_DIR}` : '',
-      NODE_ENV ? `NODE_ENV=${NODE_ENV}` : ''
-    )
-  }
-}
 
-// Some checks on configuration files
-// Return an error message, or null if everything is okay
-function checkConfig () {
-  const defaultNSFWPolicy = config.get<string>('instance.default_nsfw_policy')
-
-  // NSFW policy
-  if ([ 'do_not_list', 'blur', 'display' ].indexOf(defaultNSFWPolicy) === -1) {
-    return 'NSFW policy setting should be "do_not_list" or "blur" or "display" instead of ' + defaultNSFWPolicy
-  }
-
-  // Redundancies
-  const redundancyVideos = config.get<VideosRedundancy[]>('redundancy.videos.strategies')
-  if (isArray(redundancyVideos)) {
-    for (const r of redundancyVideos) {
-      if ([ 'most-views', 'trending', 'recently-added' ].indexOf(r.strategy) === -1) {
-        return 'Redundancy video entries should have "most-views" strategy instead of ' + r.strategy
-      }
-    }
-
-    const filtered = uniq(redundancyVideos.map(r => r.strategy))
-    if (filtered.length !== redundancyVideos.length) {
-      return 'Redundancy video entries should have unique strategies'
-    }
-
-    const recentlyAddedStrategy = redundancyVideos.find(r => r.strategy === 'recently-added') as RecentlyAddedStrategy
-    if (recentlyAddedStrategy && isNaN(recentlyAddedStrategy.minViews)) {
-      return 'Min views in recently added strategy is not a number'
-    }
-  }
-
-  if (isProdInstance()) {
-    const configStorage = config.get('storage')
-    for (const key of Object.keys(configStorage)) {
-      if (configStorage[key].startsWith('storage/')) {
-        logger.warn(
-          'Directory of %s should not be in the production directory of PeerTube. Please check your production configuration file.',
-          key
-        )
-      }
-    }
-  }
-
-  return null
-}
+// ONLY USE CORE MODULES IN THIS FILE!
 
 // Check the config files
 function checkMissedConfig () {
@@ -109,6 +39,14 @@ function checkMissedConfig () {
     }
   }
 
+  const redundancyVideos = config.get<any>('redundancy.videos.strategies')
+  if (isArray(redundancyVideos)) {
+    for (const r of redundancyVideos) {
+      if (!r.size) miss.push('redundancy.videos.strategies.size')
+      if (!r.min_lifetime) miss.push('redundancy.videos.strategies.min_lifetime')
+    }
+  }
+
   const missingAlternatives = requiredAlternatives.filter(
     set => !set.find(alternative => !alternative.find(key => !config.has(key)))
   )
@@ -163,36 +101,10 @@ async function checkFFmpegEncoders (): Promise<Map<string, boolean>> {
   }
 }
 
-// We get db by param to not import it in this file (import orders)
-async function clientsExist () {
-  const totalClients = await OAuthClientModel.countTotal()
-
-  return totalClients !== 0
-}
-
-// We get db by param to not import it in this file (import orders)
-async function usersExist () {
-  const totalUsers = await UserModel.countTotal()
-
-  return totalUsers !== 0
-}
-
-// We get db by param to not import it in this file (import orders)
-async function applicationExist () {
-  const totalApplication = await ApplicationModel.countTotal()
-
-  return totalApplication !== 0
-}
-
 // ---------------------------------------------------------------------------
 
 export {
-  checkConfig,
   checkFFmpeg,
   checkFFmpegEncoders,
-  checkMissedConfig,
-  clientsExist,
-  usersExist,
-  applicationExist,
-  checkActivityPubUrls
+  checkMissedConfig
 }
diff --git a/server/initializers/constants.ts b/server/initializers/constants.ts
index 03424ffb8..947cbda28 100644
--- a/server/initializers/constants.ts
+++ b/server/initializers/constants.ts
@@ -601,7 +601,6 @@ const MEMOIZE_TTL = {
 
 const REDUNDANCY = {
   VIDEOS: {
-    EXPIRES_AFTER_MS: 48 * 3600 * 1000, // 2 days
     RANDOMIZED_FACTOR: 5
   }
 }
@@ -750,10 +749,16 @@ function updateWebserverConfig () {
   CONFIG.WEBSERVER.HOST = sanitizeHost(CONFIG.WEBSERVER.HOSTNAME + ':' + CONFIG.WEBSERVER.PORT, REMOTE_SCHEME.HTTP)
 }
 
-function buildVideosRedundancy (objs: VideosRedundancy[]): VideosRedundancy[] {
+function buildVideosRedundancy (objs: any[]): VideosRedundancy[] {
   if (!objs) return []
 
-  return objs.map(obj => Object.assign(obj, { size: bytes.parse(obj.size) }))
+  return objs.map(obj => {
+    return Object.assign(obj, {
+      minLifetime: parseDuration(obj.min_lifetime),
+      size: bytes.parse(obj.size),
+      minViews: obj.min_views
+    })
+  })
 }
 
 function buildLanguages () {
diff --git a/server/initializers/index.ts b/server/initializers/index.ts
index 332702774..fe9190a9c 100644
--- a/server/initializers/index.ts
+++ b/server/initializers/index.ts
@@ -1,6 +1,5 @@
 // Constants first, database in second!
 export * from './constants'
 export * from './database'
-export * from './checker'
 export * from './installer'
 export * from './migrator'
diff --git a/server/initializers/installer.ts b/server/initializers/installer.ts
index 818bb04a2..c952ad46c 100644
--- a/server/initializers/installer.ts
+++ b/server/initializers/installer.ts
@@ -5,7 +5,7 @@ import { createApplicationActor, createUserAccountAndChannel } from '../lib/user
 import { UserModel } from '../models/account/user'
 import { ApplicationModel } from '../models/application/application'
 import { OAuthClientModel } from '../models/oauth/oauth-client'
-import { applicationExist, clientsExist, usersExist } from './checker'
+import { applicationExist, clientsExist, usersExist } from './checker-after-init'
 import { CACHE, CONFIG, LAST_MIGRATION_VERSION } from './constants'
 import { sequelizeTypescript } from './database'
 import { remove, ensureDir } from 'fs-extra'
diff --git a/server/lib/activitypub/audience.ts b/server/lib/activitypub/audience.ts
index a86428461..10277eca7 100644
--- a/server/lib/activitypub/audience.ts
+++ b/server/lib/activitypub/audience.ts
@@ -50,7 +50,12 @@ function getAudienceFromFollowersOf (actorsInvolvedInObject: ActorModel[]): Acti
 
 async function getActorsInvolvedInVideo (video: VideoModel, t: Transaction) {
   const actors = await VideoShareModel.loadActorsByShare(video.id, t)
-  actors.push(video.VideoChannel.Account.Actor)
+
+  const videoActor = video.VideoChannel && video.VideoChannel.Account
+    ? video.VideoChannel.Account.Actor
+    : await ActorModel.loadAccountActorByVideoId(video.id, t)
+
+  actors.push(videoActor)
 
   return actors
 }
diff --git a/server/lib/activitypub/cache-file.ts b/server/lib/activitypub/cache-file.ts
index 87f8a4162..5286d8e6d 100644
--- a/server/lib/activitypub/cache-file.ts
+++ b/server/lib/activitypub/cache-file.ts
@@ -1,7 +1,7 @@
 import { CacheFileObject } from '../../../shared/index'
 import { VideoModel } from '../../models/video/video'
-import { sequelizeTypescript } from '../../initializers'
 import { VideoRedundancyModel } from '../../models/redundancy/video-redundancy'
+import { Transaction } from 'sequelize'
 
 function cacheFileActivityObjectToDBAttributes (cacheFileObject: CacheFileObject, video: VideoModel, byActor: { id?: number }) {
   const url = cacheFileObject.url
@@ -22,25 +22,29 @@ function cacheFileActivityObjectToDBAttributes (cacheFileObject: CacheFileObject
   }
 }
 
-function createCacheFile (cacheFileObject: CacheFileObject, video: VideoModel, byActor: { id?: number }) {
-  return sequelizeTypescript.transaction(async t => {
-    const attributes = cacheFileActivityObjectToDBAttributes(cacheFileObject, video, byActor)
+function createCacheFile (cacheFileObject: CacheFileObject, video: VideoModel, byActor: { id?: number }, t: Transaction) {
+  const attributes = cacheFileActivityObjectToDBAttributes(cacheFileObject, video, byActor)
 
-    return VideoRedundancyModel.create(attributes, { transaction: t })
-  })
+  return VideoRedundancyModel.create(attributes, { transaction: t })
 }
 
-function updateCacheFile (cacheFileObject: CacheFileObject, redundancyModel: VideoRedundancyModel, byActor: { id?: number }) {
+function updateCacheFile (
+  cacheFileObject: CacheFileObject,
+  redundancyModel: VideoRedundancyModel,
+  video: VideoModel,
+  byActor: { id?: number },
+  t: Transaction
+) {
   if (redundancyModel.actorId !== byActor.id) {
     throw new Error('Cannot update redundancy ' + redundancyModel.url + ' of another actor.')
   }
 
-  const attributes = cacheFileActivityObjectToDBAttributes(cacheFileObject, redundancyModel.VideoFile.Video, byActor)
+  const attributes = cacheFileActivityObjectToDBAttributes(cacheFileObject, video, byActor)
 
   redundancyModel.set('expires', attributes.expiresOn)
   redundancyModel.set('fileUrl', attributes.fileUrl)
 
-  return redundancyModel.save()
+  return redundancyModel.save({ transaction: t })
 }
 
 export {
diff --git a/server/lib/activitypub/process/process-create.ts b/server/lib/activitypub/process/process-create.ts
index cff8dcfc6..ceb5413ca 100644
--- a/server/lib/activitypub/process/process-create.ts
+++ b/server/lib/activitypub/process/process-create.ts
@@ -95,7 +95,7 @@ async function processCreateView (byActor: ActorModel, activity: ActivityCreate)
   if (video.isOwned()) {
     // Don't resend the activity to the sender
     const exceptions = [ byActor ]
-    await forwardActivity(activity, undefined, exceptions)
+    await forwardVideoRelatedActivity(activity, undefined, exceptions, video)
   }
 }
 
@@ -104,12 +104,14 @@ async function processCacheFile (byActor: ActorModel, activity: ActivityCreate)
 
   const { video } = await getOrCreateVideoAndAccountAndChannel({ videoObject: cacheFile.object })
 
-  await createCacheFile(cacheFile, video, byActor)
+  await sequelizeTypescript.transaction(async t => {
+    return createCacheFile(cacheFile, video, byActor, t)
+  })
 
   if (video.isOwned()) {
     // Don't resend the activity to the sender
     const exceptions = [ byActor ]
-    await forwardActivity(activity, undefined, exceptions)
+    await forwardVideoRelatedActivity(activity, undefined, exceptions, video)
   }
 }
 
diff --git a/server/lib/activitypub/process/process-undo.ts b/server/lib/activitypub/process/process-undo.ts
index 73ca0a17c..ff019cd8c 100644
--- a/server/lib/activitypub/process/process-undo.ts
+++ b/server/lib/activitypub/process/process-undo.ts
@@ -100,7 +100,7 @@ async function processUndoCacheFile (byActor: ActorModel, activity: ActivityUndo
 
   return sequelizeTypescript.transaction(async t => {
     const cacheFile = await VideoRedundancyModel.loadByUrl(cacheFileObject.id)
-    if (!cacheFile) throw new Error('Unknown video cache ' + cacheFile.url)
+    if (!cacheFile) throw new Error('Unknown video cache ' + cacheFileObject.id)
 
     if (cacheFile.actorId !== byActor.id) throw new Error('Cannot delete redundancy ' + cacheFile.url + ' of another actor.')
 
diff --git a/server/lib/activitypub/process/process-update.ts b/server/lib/activitypub/process/process-update.ts
index ed3489ebf..e092a6729 100644
--- a/server/lib/activitypub/process/process-update.ts
+++ b/server/lib/activitypub/process/process-update.ts
@@ -12,6 +12,7 @@ import { sanitizeAndCheckVideoTorrentObject } from '../../../helpers/custom-vali
 import { isCacheFileObjectValid } from '../../../helpers/custom-validators/activitypub/cache-file'
 import { VideoRedundancyModel } from '../../../models/redundancy/video-redundancy'
 import { createCacheFile, updateCacheFile } from '../cache-file'
+import { forwardVideoRelatedActivity } from '../send/utils'
 
 async function processUpdateActivity (activity: ActivityUpdate, byActor: ActorModel) {
   const objectType = activity.object.type
@@ -68,18 +69,29 @@ async function processUpdateVideo (actor: ActorModel, activity: ActivityUpdate)
 async function processUpdateCacheFile (byActor: ActorModel, activity: ActivityUpdate) {
   const cacheFileObject = activity.object as CacheFileObject
 
-  if (!isCacheFileObjectValid(cacheFileObject) === false) {
-    logger.debug('Cahe file object sent by update is not valid.', { cacheFileObject })
+  if (!isCacheFileObjectValid(cacheFileObject)) {
+    logger.debug('Cache file object sent by update is not valid.', { cacheFileObject })
     return undefined
   }
 
-  const redundancyModel = await VideoRedundancyModel.loadByUrl(cacheFileObject.id)
-  if (!redundancyModel) {
-    const { video } = await getOrCreateVideoAndAccountAndChannel({ videoObject: cacheFileObject.id })
-    return createCacheFile(cacheFileObject, video, byActor)
-  }
+  const { video } = await getOrCreateVideoAndAccountAndChannel({ videoObject: cacheFileObject.object })
+
+  await sequelizeTypescript.transaction(async t => {
+    const redundancyModel = await VideoRedundancyModel.loadByUrl(cacheFileObject.id, t)
+
+    if (!redundancyModel) {
+      await createCacheFile(cacheFileObject, video, byActor, t)
+    } else {
+      await updateCacheFile(cacheFileObject, redundancyModel, video, byActor, t)
+    }
+  })
+
+  if (video.isOwned()) {
+    // Don't resend the activity to the sender
+    const exceptions = [ byActor ]
 
-  return updateCacheFile(cacheFileObject, redundancyModel, byActor)
+    await forwardVideoRelatedActivity(activity, undefined, exceptions, video)
+  }
 }
 
 async function processUpdateActor (actor: ActorModel, activity: ActivityUpdate) {
diff --git a/server/lib/activitypub/send/send-update.ts b/server/lib/activitypub/send/send-update.ts
index ec46789b7..a68f03edf 100644
--- a/server/lib/activitypub/send/send-update.ts
+++ b/server/lib/activitypub/send/send-update.ts
@@ -7,8 +7,8 @@ import { VideoModel } from '../../../models/video/video'
 import { VideoChannelModel } from '../../../models/video/video-channel'
 import { VideoShareModel } from '../../../models/video/video-share'
 import { getUpdateActivityPubUrl } from '../url'
-import { broadcastToFollowers, sendVideoRelatedActivity, unicastTo } from './utils'
-import { audiencify, getActorsInvolvedInVideo, getAudience, getAudienceFromFollowersOf } from '../audience'
+import { broadcastToFollowers, sendVideoRelatedActivity } from './utils'
+import { audiencify, getActorsInvolvedInVideo, getAudience } from '../audience'
 import { logger } from '../../../helpers/logger'
 import { VideoCaptionModel } from '../../../models/video/video-caption'
 import { VideoRedundancyModel } from '../../../models/redundancy/video-redundancy'
diff --git a/server/lib/activitypub/videos.ts b/server/lib/activitypub/videos.ts
index 48c0e0a5c..db72ef23c 100644
--- a/server/lib/activitypub/videos.ts
+++ b/server/lib/activitypub/videos.ts
@@ -176,7 +176,7 @@ async function getOrCreateVideoAndAccountAndChannel (options: {
       syncParam,
       refreshViews
     }
-    const p = retryTransactionWrapper(refreshVideoIfNeeded, refreshOptions)
+    const p = refreshVideoIfNeeded(refreshOptions)
     if (syncParam.refreshVideo === true) videoFromDatabase = await p
 
     return { video: videoFromDatabase }
@@ -245,29 +245,37 @@ async function updateVideoFromAP (options: {
       generateThumbnailFromUrl(options.video, options.videoObject.icon)
         .catch(err => logger.warn('Cannot generate thumbnail of %s.', options.videoObject.id, { err }))
 
-      // Remove old video files
-      const videoFileDestroyTasks: Bluebird<void>[] = []
-      for (const videoFile of options.video.VideoFiles) {
-        videoFileDestroyTasks.push(videoFile.destroy(sequelizeOptions))
-      }
-      await Promise.all(videoFileDestroyTasks)
+      {
+        const videoFileAttributes = videoFileActivityUrlToDBAttributes(options.video, options.videoObject)
+        const newVideoFiles = videoFileAttributes.map(a => new VideoFileModel(a))
 
-      const videoFileAttributes = videoFileActivityUrlToDBAttributes(options.video, options.videoObject)
-      const tasks = videoFileAttributes.map(f => VideoFileModel.create(f, sequelizeOptions))
-      await Promise.all(tasks)
+        // Remove video files that do not exist anymore
+        const destroyTasks = options.video.VideoFiles
+                                    .filter(f => !newVideoFiles.find(newFile => newFile.hasSameUniqueKeysThan(f)))
+                                    .map(f => f.destroy(sequelizeOptions))
+        await Promise.all(destroyTasks)
 
-      // Update Tags
-      const tags = options.videoObject.tag.map(tag => tag.name)
-      const tagInstances = await TagModel.findOrCreateTags(tags, t)
-      await options.video.$set('Tags', tagInstances, sequelizeOptions)
+        // Update or add other one
+        const upsertTasks = videoFileAttributes.map(a => VideoFileModel.upsert(a, sequelizeOptions))
+        await Promise.all(upsertTasks)
+      }
 
-      // Update captions
-      await VideoCaptionModel.deleteAllCaptionsOfRemoteVideo(options.video.id, t)
+      {
+        // Update Tags
+        const tags = options.videoObject.tag.map(tag => tag.name)
+        const tagInstances = await TagModel.findOrCreateTags(tags, t)
+        await options.video.$set('Tags', tagInstances, sequelizeOptions)
+      }
 
-      const videoCaptionsPromises = options.videoObject.subtitleLanguage.map(c => {
-        return VideoCaptionModel.insertOrReplaceLanguage(options.video.id, c.identifier, t)
-      })
-      await Promise.all(videoCaptionsPromises)
+      {
+        // Update captions
+        await VideoCaptionModel.deleteAllCaptionsOfRemoteVideo(options.video.id, t)
+
+        const videoCaptionsPromises = options.videoObject.subtitleLanguage.map(c => {
+          return VideoCaptionModel.insertOrReplaceLanguage(options.video.id, c.identifier, t)
+        })
+        await Promise.all(videoCaptionsPromises)
+      }
     })
 
     logger.info('Remote video with uuid %s updated', options.videoObject.uuid)
@@ -382,7 +390,7 @@ async function refreshVideoIfNeeded (options: {
       channel: channelActor.VideoChannel,
       updateViews: options.refreshViews
     }
-    await updateVideoFromAP(updateOptions)
+    await retryTransactionWrapper(updateVideoFromAP, updateOptions)
     await syncVideoExternalAttributes(video, videoObject, options.syncParam)
   } catch (err) {
     logger.warn('Cannot refresh video.', { err })
diff --git a/server/lib/cache/index.ts b/server/lib/cache/index.ts
index 7bf63790a..54eb983fa 100644
--- a/server/lib/cache/index.ts
+++ b/server/lib/cache/index.ts
@@ -1 +1,2 @@
 export * from './videos-preview-cache'
+export * from './videos-caption-cache'
diff --git a/server/lib/redundancy.ts b/server/lib/redundancy.ts
index 78221cc3d..16b122658 100644
--- a/server/lib/redundancy.ts
+++ b/server/lib/redundancy.ts
@@ -6,7 +6,8 @@ import { getServerActor } from '../helpers/utils'
 async function removeVideoRedundancy (videoRedundancy: VideoRedundancyModel, t?: Transaction) {
   const serverActor = await getServerActor()
 
-  await sendUndoCacheFile(serverActor, videoRedundancy, t)
+  // Local cache, send undo to remote instances
+  if (videoRedundancy.actorId === serverActor.id) await sendUndoCacheFile(serverActor, videoRedundancy, t)
 
   await videoRedundancy.destroy({ transaction: t })
 }
diff --git a/server/lib/schedulers/videos-redundancy-scheduler.ts b/server/lib/schedulers/videos-redundancy-scheduler.ts
index 998d2295a..97df3e4f5 100644
--- a/server/lib/schedulers/videos-redundancy-scheduler.ts
+++ b/server/lib/schedulers/videos-redundancy-scheduler.ts
@@ -1,7 +1,7 @@
 import { AbstractScheduler } from './abstract-scheduler'
-import { CONFIG, JOB_TTL, REDUNDANCY, SCHEDULER_INTERVALS_MS } from '../../initializers'
+import { CONFIG, JOB_TTL, REDUNDANCY } from '../../initializers'
 import { logger } from '../../helpers/logger'
-import { VideoRedundancyStrategy, VideosRedundancy } from '../../../shared/models/redundancy'
+import { VideosRedundancy } from '../../../shared/models/redundancy'
 import { VideoRedundancyModel } from '../../models/redundancy/video-redundancy'
 import { VideoFileModel } from '../../models/video/video-file'
 import { downloadWebTorrentVideo } from '../../helpers/webtorrent'
@@ -12,6 +12,7 @@ import { sendCreateCacheFile, sendUpdateCacheFile } from '../activitypub/send'
 import { VideoModel } from '../../models/video/video'
 import { getVideoCacheFileActivityPubUrl } from '../activitypub/url'
 import { isTestInstance } from '../../helpers/core-utils'
+import { removeVideoRedundancy } from '../redundancy'
 
 export class VideosRedundancyScheduler extends AbstractScheduler {
 
@@ -30,7 +31,7 @@ export class VideosRedundancyScheduler extends AbstractScheduler {
     this.executing = true
 
     for (const obj of CONFIG.REDUNDANCY.VIDEOS.STRATEGIES) {
-      if (!isTestInstance()) logger.info('Running redundancy scheduler for strategy %s.', obj.strategy)
+      logger.info('Running redundancy scheduler for strategy %s.', obj.strategy)
 
       try {
         const videoToDuplicate = await this.findVideoToDuplicate(obj)
@@ -39,20 +40,24 @@ export class VideosRedundancyScheduler extends AbstractScheduler {
         const videoFiles = videoToDuplicate.VideoFiles
         videoFiles.forEach(f => f.Video = videoToDuplicate)
 
-        if (await this.isTooHeavy(obj.strategy, videoFiles, obj.size)) {
-          if (!isTestInstance()) logger.info('Video %s is too big for our cache, skipping.', videoToDuplicate.url)
+        await this.purgeCacheIfNeeded(obj, videoFiles)
+
+        if (await this.isTooHeavy(obj, videoFiles)) {
+          logger.info('Video %s is too big for our cache, skipping.', videoToDuplicate.url)
           continue
         }
 
         logger.info('Will duplicate video %s in redundancy scheduler "%s".', videoToDuplicate.url, obj.strategy)
 
-        await this.createVideoRedundancy(obj.strategy, videoFiles)
+        await this.createVideoRedundancy(obj, videoFiles)
       } catch (err) {
         logger.error('Cannot run videos redundancy %s.', obj.strategy, { err })
       }
     }
 
-    await this.removeExpired()
+    await this.extendsLocalExpiration()
+
+    await this.purgeRemoteExpired()
 
     this.executing = false
   }
@@ -61,16 +66,27 @@ export class VideosRedundancyScheduler extends AbstractScheduler {
     return this.instance || (this.instance = new this())
   }
 
-  private async removeExpired () {
-    const expired = await VideoRedundancyModel.listAllExpired()
+  private async extendsLocalExpiration () {
+    const expired = await VideoRedundancyModel.listLocalExpired()
+
+    for (const redundancyModel of expired) {
+      try {
+        const redundancy = CONFIG.REDUNDANCY.VIDEOS.STRATEGIES.find(s => s.strategy === redundancyModel.strategy)
+        await this.extendsExpirationOf(redundancyModel, redundancy.minLifetime)
+      } catch (err) {
+        logger.error('Cannot extend expiration of %s video from our redundancy system.', this.buildEntryLogId(redundancyModel))
+      }
+    }
+  }
 
-    for (const m of expired) {
-      logger.info('Removing expired video %s from our redundancy system.', this.buildEntryLogId(m))
+  private async purgeRemoteExpired () {
+    const expired = await VideoRedundancyModel.listRemoteExpired()
 
+    for (const redundancyModel of expired) {
       try {
-        await m.destroy()
+        await removeVideoRedundancy(redundancyModel)
       } catch (err) {
-        logger.error('Cannot remove %s video from our redundancy system.', this.buildEntryLogId(m))
+        logger.error('Cannot remove redundancy %s from our redundancy system.', this.buildEntryLogId(redundancyModel))
       }
     }
   }
@@ -90,18 +106,14 @@ export class VideosRedundancyScheduler extends AbstractScheduler {
     }
   }
 
-  private async createVideoRedundancy (strategy: VideoRedundancyStrategy, filesToDuplicate: VideoFileModel[]) {
+  private async createVideoRedundancy (redundancy: VideosRedundancy, filesToDuplicate: VideoFileModel[]) {
     const serverActor = await getServerActor()
 
     for (const file of filesToDuplicate) {
       const existing = await VideoRedundancyModel.loadByFileId(file.id)
       if (existing) {
-        logger.info('Duplicating %s - %d in videos redundancy with "%s" strategy.', file.Video.url, file.resolution, strategy)
+        await this.extendsExpirationOf(existing, redundancy.minLifetime)
 
-        existing.expiresOn = this.buildNewExpiration()
-        await existing.save()
-
-        await sendUpdateCacheFile(serverActor, existing)
         continue
       }
 
@@ -109,7 +121,7 @@ export class VideosRedundancyScheduler extends AbstractScheduler {
       const video = await VideoModel.loadAndPopulateAccountAndServerAndTags(file.Video.id)
       if (!video) continue
 
-      logger.info('Duplicating %s - %d in videos redundancy with "%s" strategy.', video.url, file.resolution, strategy)
+      logger.info('Duplicating %s - %d in videos redundancy with "%s" strategy.', video.url, file.resolution, redundancy.strategy)
 
       const { baseUrlHttp, baseUrlWs } = video.getBaseUrls()
       const magnetUri = video.generateMagnetUri(file, baseUrlHttp, baseUrlWs)
@@ -120,10 +132,10 @@ export class VideosRedundancyScheduler extends AbstractScheduler {
       await rename(tmpPath, destPath)
 
       const createdModel = await VideoRedundancyModel.create({
-        expiresOn: new Date(Date.now() + REDUNDANCY.VIDEOS.EXPIRES_AFTER_MS),
+        expiresOn: this.buildNewExpiration(redundancy.minLifetime),
         url: getVideoCacheFileActivityPubUrl(file),
         fileUrl: video.getVideoFileUrl(file, CONFIG.WEBSERVER.URL),
-        strategy,
+        strategy: redundancy.strategy,
         videoFileId: file.id,
         actorId: serverActor.id
       })
@@ -133,16 +145,36 @@ export class VideosRedundancyScheduler extends AbstractScheduler {
     }
   }
 
-  private async isTooHeavy (strategy: VideoRedundancyStrategy, filesToDuplicate: VideoFileModel[], maxSizeArg: number) {
-    const maxSize = maxSizeArg - this.getTotalFileSizes(filesToDuplicate)
+  private async extendsExpirationOf (redundancy: VideoRedundancyModel, expiresAfterMs: number) {
+    logger.info('Extending expiration of %s.', redundancy.url)
+
+    const serverActor = await getServerActor()
+
+    redundancy.expiresOn = this.buildNewExpiration(expiresAfterMs)
+    await redundancy.save()
+
+    await sendUpdateCacheFile(serverActor, redundancy)
+  }
+
+  private async purgeCacheIfNeeded (redundancy: VideosRedundancy, filesToDuplicate: VideoFileModel[]) {
+    while (this.isTooHeavy(redundancy, filesToDuplicate)) {
+      const toDelete = await VideoRedundancyModel.loadOldestLocalThatAlreadyExpired(redundancy.strategy, redundancy.minLifetime)
+      if (!toDelete) return
+
+      await removeVideoRedundancy(toDelete)
+    }
+  }
+
+  private async isTooHeavy (redundancy: VideosRedundancy, filesToDuplicate: VideoFileModel[]) {
+    const maxSize = redundancy.size - this.getTotalFileSizes(filesToDuplicate)
 
-    const totalDuplicated = await VideoRedundancyModel.getTotalDuplicated(strategy)
+    const totalDuplicated = await VideoRedundancyModel.getTotalDuplicated(redundancy.strategy)
 
     return totalDuplicated > maxSize
   }
 
-  private buildNewExpiration () {
-    return new Date(Date.now() + REDUNDANCY.VIDEOS.EXPIRES_AFTER_MS)
+  private buildNewExpiration (expiresAfterMs: number) {
+    return new Date(Date.now() + expiresAfterMs)
   }
 
   private buildEntryLogId (object: VideoRedundancyModel) {
diff --git a/server/models/activitypub/actor.ts b/server/models/activitypub/actor.ts
index f8bb59323..12b83916e 100644
--- a/server/models/activitypub/actor.ts
+++ b/server/models/activitypub/actor.ts
@@ -37,6 +37,7 @@ import { ServerModel } from '../server/server'
 import { throwIfNotValid } from '../utils'
 import { VideoChannelModel } from '../video/video-channel'
 import { ActorFollowModel } from './actor-follow'
+import { VideoModel } from '../video/video'
 
 enum ScopeNames {
   FULL = 'FULL'
@@ -266,6 +267,36 @@ export class ActorModel extends Model<ActorModel> {
     return ActorModel.unscoped().findById(id)
   }
 
+  static loadAccountActorByVideoId (videoId: number, transaction: Sequelize.Transaction) {
+    const query = {
+      include: [
+        {
+          attributes: [ 'id' ],
+          model: AccountModel.unscoped(),
+          required: true,
+          include: [
+            {
+              attributes: [ 'id' ],
+              model: VideoChannelModel.unscoped(),
+              required: true,
+              include: {
+                attributes: [ 'id' ],
+                model: VideoModel.unscoped(),
+                required: true,
+                where: {
+                  id: videoId
+                }
+              }
+            }
+          ]
+        }
+      ],
+      transaction
+    }
+
+    return ActorModel.unscoped().findOne(query as any) // FIXME: typings
+  }
+
   static isActorUrlExist (url: string) {
     const query = {
       raw: true,
diff --git a/server/models/redundancy/video-redundancy.ts b/server/models/redundancy/video-redundancy.ts
index fb07287a8..970d2fe06 100644
--- a/server/models/redundancy/video-redundancy.ts
+++ b/server/models/redundancy/video-redundancy.ts
@@ -9,7 +9,6 @@ import {
   Is,
   Model,
   Scopes,
-  Sequelize,
   Table,
   UpdatedAt
 } from 'sequelize-typescript'
@@ -28,6 +27,7 @@ import { ServerModel } from '../server/server'
 import { sample } from 'lodash'
 import { isTestInstance } from '../../helpers/core-utils'
 import * as Bluebird from 'bluebird'
+import * as Sequelize from 'sequelize'
 
 export enum ScopeNames {
   WITH_VIDEO = 'WITH_VIDEO'
@@ -116,11 +116,11 @@ export class VideoRedundancyModel extends Model<VideoRedundancyModel> {
   Actor: ActorModel
 
   @AfterDestroy
-  static removeFilesAndSendDelete (instance: VideoRedundancyModel) {
+  static removeFile (instance: VideoRedundancyModel) {
     // Not us
     if (!instance.strategy) return
 
-    logger.info('Removing video file %s-.', instance.VideoFile.Video.uuid, instance.VideoFile.resolution)
+    logger.info('Removing duplicated video file %s-%s.', instance.VideoFile.Video.uuid, instance.VideoFile.resolution)
 
     return instance.VideoFile.Video.removeFile(instance.VideoFile)
   }
@@ -135,11 +135,12 @@ export class VideoRedundancyModel extends Model<VideoRedundancyModel> {
     return VideoRedundancyModel.scope(ScopeNames.WITH_VIDEO).findOne(query)
   }
 
-  static loadByUrl (url: string) {
+  static loadByUrl (url: string, transaction?: Sequelize.Transaction) {
     const query = {
       where: {
         url
-      }
+      },
+      transaction
     }
 
     return VideoRedundancyModel.findOne(query)
@@ -157,7 +158,6 @@ export class VideoRedundancyModel extends Model<VideoRedundancyModel> {
     // On VideoModel!
     const query = {
       attributes: [ 'id', 'views' ],
-      logging: !isTestInstance(),
       limit: randomizedFactor,
       order: getVideoSort('-views'),
       include: [
@@ -174,7 +174,6 @@ export class VideoRedundancyModel extends Model<VideoRedundancyModel> {
     const query = {
       attributes: [ 'id', 'views' ],
       subQuery: false,
-      logging: !isTestInstance(),
       group: 'VideoModel.id',
       limit: randomizedFactor,
       order: getVideoSort('-trending'),
@@ -193,7 +192,6 @@ export class VideoRedundancyModel extends Model<VideoRedundancyModel> {
     // On VideoModel!
     const query = {
       attributes: [ 'id', 'publishedAt' ],
-      logging: !isTestInstance(),
       limit: randomizedFactor,
       order: getVideoSort('-publishedAt'),
       where: {
@@ -210,11 +208,29 @@ export class VideoRedundancyModel extends Model<VideoRedundancyModel> {
     return VideoRedundancyModel.getVideoSample(VideoModel.unscoped().findAll(query))
   }
 
+  static async loadOldestLocalThatAlreadyExpired (strategy: VideoRedundancyStrategy, expiresAfterMs: number) {
+    const expiredDate = new Date()
+    expiredDate.setMilliseconds(expiredDate.getMilliseconds() - expiresAfterMs)
+
+    const actor = await getServerActor()
+
+    const query = {
+      where: {
+        actorId: actor.id,
+        strategy,
+        createdAt: {
+          [ Sequelize.Op.lt ]: expiredDate
+        }
+      }
+    }
+
+    return VideoRedundancyModel.scope([ ScopeNames.WITH_VIDEO ]).findOne(query)
+  }
+
   static async getTotalDuplicated (strategy: VideoRedundancyStrategy) {
     const actor = await getServerActor()
 
     const options = {
-      logging: !isTestInstance(),
       include: [
         {
           attributes: [],
@@ -228,21 +244,39 @@ export class VideoRedundancyModel extends Model<VideoRedundancyModel> {
       ]
     }
 
-    return VideoFileModel.sum('size', options)
+    return VideoFileModel.sum('size', options as any) // FIXME: typings
   }
 
-  static listAllExpired () {
+  static async listLocalExpired () {
+    const actor = await getServerActor()
+
+    const query = {
+      where: {
+        actorId: actor.id,
+        expiresOn: {
+          [ Sequelize.Op.lt ]: new Date()
+        }
+      }
+    }
+
+    return VideoRedundancyModel.scope([ ScopeNames.WITH_VIDEO ]).findAll(query)
+  }
+
+  static async listRemoteExpired () {
+    const actor = await getServerActor()
+
     const query = {
-      logging: !isTestInstance(),
       where: {
+        actorId: {
+          [Sequelize.Op.ne]: actor.id
+        },
         expiresOn: {
           [ Sequelize.Op.lt ]: new Date()
         }
       }
     }
 
-    return VideoRedundancyModel.scope(ScopeNames.WITH_VIDEO)
-                               .findAll(query)
+    return VideoRedundancyModel.scope([ ScopeNames.WITH_VIDEO ]).findAll(query)
   }
 
   static async getStats (strategy: VideoRedundancyStrategy) {
@@ -299,7 +333,7 @@ export class VideoRedundancyModel extends Model<VideoRedundancyModel> {
 
     const notIn = Sequelize.literal(
       '(' +
-        `SELECT "videoFileId" FROM "videoRedundancy" WHERE "actorId" = ${actor.id} AND "expiresOn" >= NOW()` +
+        `SELECT "videoFileId" FROM "videoRedundancy" WHERE "actorId" = ${actor.id}` +
       ')'
     )
 
diff --git a/server/models/video/video-file.ts b/server/models/video/video-file.ts
index 0907ea569..0887a3738 100644
--- a/server/models/video/video-file.ts
+++ b/server/models/video/video-file.ts
@@ -106,4 +106,10 @@ export class VideoFileModel extends Model<VideoFileModel> {
                 return results.length === 1
               })
   }
+
+  hasSameUniqueKeysThan (other: VideoFileModel) {
+    return this.fps === other.fps &&
+      this.resolution === other.resolution &&
+      this.videoId === other.videoId
+  }
 }
diff --git a/server/tests/api/server/redundancy.ts b/server/tests/api/server/redundancy.ts
index 6ce4b9dd1..a773e3de4 100644
--- a/server/tests/api/server/redundancy.ts
+++ b/server/tests/api/server/redundancy.ts
@@ -31,14 +31,13 @@ const expect = chai.expect
 
 let servers: ServerInfo[] = []
 let video1Server2UUID: string
-let video2Server2UUID: string
 
-function checkMagnetWebseeds (file: { magnetUri: string, resolution: { id: number } }, baseWebseeds: string[]) {
+function checkMagnetWebseeds (file: { magnetUri: string, resolution: { id: number } }, baseWebseeds: string[], server: ServerInfo) {
   const parsed = magnetUtil.decode(file.magnetUri)
 
   for (const ws of baseWebseeds) {
     const found = parsed.urlList.find(url => url === `${ws}-${file.resolution.id}.mp4`)
-    expect(found, `Webseed ${ws} not found in ${file.magnetUri}`).to.not.be.undefined
+    expect(found, `Webseed ${ws} not found in ${file.magnetUri} on server ${server.url}`).to.not.be.undefined
   }
 }
 
@@ -49,6 +48,7 @@ async function runServers (strategy: VideoRedundancyStrategy, additionalParams:
         check_interval: '5 seconds',
         strategies: [
           immutableAssign({
+            min_lifetime: '1 hour',
             strategy: strategy,
             size: '100KB'
           }, additionalParams)
@@ -68,11 +68,6 @@ async function runServers (strategy: VideoRedundancyStrategy, additionalParams:
     await viewVideo(servers[ 1 ].url, video1Server2UUID)
   }
 
-  {
-    const res = await uploadVideo(servers[ 1 ].url, servers[ 1 ].accessToken, { name: 'video 2 server 2' })
-    video2Server2UUID = res.body.video.uuid
-  }
-
   await waitJobs(servers)
 
   // Server 1 and server 2 follow each other
@@ -85,68 +80,69 @@ async function runServers (strategy: VideoRedundancyStrategy, additionalParams:
   await waitJobs(servers)
 }
 
-async function check1WebSeed (strategy: VideoRedundancyStrategy) {
+async function check1WebSeed (strategy: VideoRedundancyStrategy, videoUUID?: string) {
+  if (!videoUUID) videoUUID = video1Server2UUID
+
   const webseeds = [
-    'http://localhost:9002/static/webseed/' + video1Server2UUID
+    'http://localhost:9002/static/webseed/' + videoUUID
   ]
 
   for (const server of servers) {
     {
-      const res = await getVideo(server.url, video1Server2UUID)
+      const res = await getVideo(server.url, videoUUID)
 
       const video: VideoDetails = res.body
-      video.files.forEach(f => checkMagnetWebseeds(f, webseeds))
+      for (const f of video.files) {
+        checkMagnetWebseeds(f, webseeds, server)
+      }
     }
+  }
+}
 
-    {
-      const res = await getStats(server.url)
-      const data: ServerStats = res.body
+async function checkStatsWith2Webseed (strategy: VideoRedundancyStrategy) {
+  const res = await getStats(servers[0].url)
+  const data: ServerStats = res.body
 
-      expect(data.videosRedundancy).to.have.lengthOf(1)
+  expect(data.videosRedundancy).to.have.lengthOf(1)
+  const stat = data.videosRedundancy[0]
 
-      const stat = data.videosRedundancy[0]
-      expect(stat.strategy).to.equal(strategy)
-      expect(stat.totalSize).to.equal(102400)
-      expect(stat.totalUsed).to.equal(0)
-      expect(stat.totalVideoFiles).to.equal(0)
-      expect(stat.totalVideos).to.equal(0)
-    }
-  }
+  expect(stat.strategy).to.equal(strategy)
+  expect(stat.totalSize).to.equal(102400)
+  expect(stat.totalUsed).to.be.at.least(1).and.below(102401)
+  expect(stat.totalVideoFiles).to.equal(4)
+  expect(stat.totalVideos).to.equal(1)
 }
 
-async function enableRedundancy () {
-  await updateRedundancy(servers[ 0 ].url, servers[ 0 ].accessToken, servers[ 1 ].host, true)
+async function checkStatsWith1Webseed (strategy: VideoRedundancyStrategy) {
+  const res = await getStats(servers[0].url)
+  const data: ServerStats = res.body
 
-  const res = await getFollowingListPaginationAndSort(servers[ 0 ].url, 0, 5, '-createdAt')
-  const follows: ActorFollow[] = res.body.data
-  const server2 = follows.find(f => f.following.host === 'localhost:9002')
-  const server3 = follows.find(f => f.following.host === 'localhost:9003')
-
-  expect(server3).to.not.be.undefined
-  expect(server3.following.hostRedundancyAllowed).to.be.false
+  expect(data.videosRedundancy).to.have.lengthOf(1)
 
-  expect(server2).to.not.be.undefined
-  expect(server2.following.hostRedundancyAllowed).to.be.true
+  const stat = data.videosRedundancy[0]
+  expect(stat.strategy).to.equal(strategy)
+  expect(stat.totalSize).to.equal(102400)
+  expect(stat.totalUsed).to.equal(0)
+  expect(stat.totalVideoFiles).to.equal(0)
+  expect(stat.totalVideos).to.equal(0)
 }
 
-async function check2Webseeds (strategy: VideoRedundancyStrategy) {
-  await waitJobs(servers)
-  await wait(15000)
-  await waitJobs(servers)
+async function check2Webseeds (strategy: VideoRedundancyStrategy, videoUUID?: string) {
+  if (!videoUUID) videoUUID = video1Server2UUID
 
   const webseeds = [
-    'http://localhost:9001/static/webseed/' + video1Server2UUID,
-    'http://localhost:9002/static/webseed/' + video1Server2UUID
+    'http://localhost:9001/static/webseed/' + videoUUID,
+    'http://localhost:9002/static/webseed/' + videoUUID
   ]
 
   for (const server of servers) {
     {
-      const res = await getVideo(server.url, video1Server2UUID)
+      const res = await getVideo(server.url, videoUUID)
 
       const video: VideoDetails = res.body
 
       for (const file of video.files) {
-        checkMagnetWebseeds(file, webseeds)
+        checkMagnetWebseeds(file, webseeds, server)
       }
     }
   }
@@ -155,22 +151,23 @@ async function check2Webseeds (strategy: VideoRedundancyStrategy) {
   expect(files).to.have.lengthOf(4)
 
   for (const resolution of [ 240, 360, 480, 720 ]) {
-    expect(files.find(f => f === `${video1Server2UUID}-${resolution}.mp4`)).to.not.be.undefined
+    expect(files.find(f => f === `${videoUUID}-${resolution}.mp4`)).to.not.be.undefined
   }
+}
 
-  {
-    const res = await getStats(servers[0].url)
-    const data: ServerStats = res.body
+async function enableRedundancyOnServer1 () {
+  await updateRedundancy(servers[ 0 ].url, servers[ 0 ].accessToken, servers[ 1 ].host, true)
 
-    expect(data.videosRedundancy).to.have.lengthOf(1)
-    const stat = data.videosRedundancy[0]
+  const res = await getFollowingListPaginationAndSort(servers[ 0 ].url, 0, 5, '-createdAt')
+  const follows: ActorFollow[] = res.body.data
+  const server2 = follows.find(f => f.following.host === 'localhost:9002')
+  const server3 = follows.find(f => f.following.host === 'localhost:9003')
 
-    expect(stat.strategy).to.equal(strategy)
-    expect(stat.totalSize).to.equal(102400)
-    expect(stat.totalUsed).to.be.at.least(1).and.below(102401)
-    expect(stat.totalVideoFiles).to.equal(4)
-    expect(stat.totalVideos).to.equal(1)
-  }
+  expect(server3).to.not.be.undefined
+  expect(server3.following.hostRedundancyAllowed).to.be.false
+
+  expect(server2).to.not.be.undefined
+  expect(server2.following.hostRedundancyAllowed).to.be.true
 }
 
 async function cleanServers () {
@@ -188,18 +185,24 @@ describe('Test videos redundancy', function () {
       return runServers(strategy)
     })
 
-    it('Should have 1 webseed on the first video', function () {
-      return check1WebSeed(strategy)
+    it('Should have 1 webseed on the first video', async function () {
+      await check1WebSeed(strategy)
+      await checkStatsWith1Webseed(strategy)
     })
 
     it('Should enable redundancy on server 1', function () {
-      return enableRedundancy()
+      return enableRedundancyOnServer1()
     })
 
-    it('Should have 2 webseed on the first video', function () {
+    it('Should have 2 webseed on the first video', async function () {
       this.timeout(40000)
 
-      return check2Webseeds(strategy)
+      await waitJobs(servers)
+      await wait(15000)
+      await waitJobs(servers)
+
+      await check2Webseeds(strategy)
+      await checkStatsWith2Webseed(strategy)
     })
 
     after(function () {
@@ -216,18 +219,24 @@ describe('Test videos redundancy', function () {
       return runServers(strategy)
     })
 
-    it('Should have 1 webseed on the first video', function () {
-      return check1WebSeed(strategy)
+    it('Should have 1 webseed on the first video', async function () {
+      await check1WebSeed(strategy)
+      await checkStatsWith1Webseed(strategy)
     })
 
     it('Should enable redundancy on server 1', function () {
-      return enableRedundancy()
+      return enableRedundancyOnServer1()
     })
 
-    it('Should have 2 webseed on the first video', function () {
+    it('Should have 2 webseed on the first video', async function () {
       this.timeout(40000)
 
-      return check2Webseeds(strategy)
+      await waitJobs(servers)
+      await wait(15000)
+      await waitJobs(servers)
+
+      await check2Webseeds(strategy)
+      await checkStatsWith2Webseed(strategy)
     })
 
     after(function () {
@@ -241,15 +250,16 @@ describe('Test videos redundancy', function () {
     before(function () {
       this.timeout(120000)
 
-      return runServers(strategy, { minViews: 3 })
+      return runServers(strategy, { min_views: 3 })
     })
 
-    it('Should have 1 webseed on the first video', function () {
-      return check1WebSeed(strategy)
+    it('Should have 1 webseed on the first video', async function () {
+      await check1WebSeed(strategy)
+      await checkStatsWith1Webseed(strategy)
     })
 
     it('Should enable redundancy on server 1', function () {
-      return enableRedundancy()
+      return enableRedundancyOnServer1()
     })
 
     it('Should still have 1 webseed on the first video', async function () {
@@ -259,10 +269,11 @@ describe('Test videos redundancy', function () {
       await wait(15000)
       await waitJobs(servers)
 
-      return check1WebSeed(strategy)
+      await check1WebSeed(strategy)
+      await checkStatsWith1Webseed(strategy)
     })
 
-    it('Should view 2 times the first video', async function () {
+    it('Should view 2 times the first video to have > min_views config', async function () {
       this.timeout(40000)
 
       await viewVideo(servers[ 0 ].url, video1Server2UUID)
@@ -272,10 +283,117 @@ describe('Test videos redundancy', function () {
       await waitJobs(servers)
     })
 
-    it('Should have 2 webseed on the first video', function () {
+    it('Should have 2 webseed on the first video', async function () {
       this.timeout(40000)
 
-      return check2Webseeds(strategy)
+      await waitJobs(servers)
+      await wait(15000)
+      await waitJobs(servers)
+
+      await check2Webseeds(strategy)
+      await checkStatsWith2Webseed(strategy)
+    })
+
+    after(function () {
+      return cleanServers()
+    })
+  })
+
+  describe('Test expiration', function () {
+    const strategy = 'recently-added'
+
+    async function checkContains (servers: ServerInfo[], str: string) {
+      for (const server of servers) {
+        const res = await getVideo(server.url, video1Server2UUID)
+        const video: VideoDetails = res.body
+
+        for (const f of video.files) {
+          expect(f.magnetUri).to.contain(str)
+        }
+      }
+    }
+
+    async function checkNotContains (servers: ServerInfo[], str: string) {
+      for (const server of servers) {
+        const res = await getVideo(server.url, video1Server2UUID)
+        const video: VideoDetails = res.body
+
+        for (const f of video.files) {
+          expect(f.magnetUri).to.not.contain(str)
+        }
+      }
+    }
+
+    before(async function () {
+      this.timeout(120000)
+
+      await runServers(strategy, { min_lifetime: '7 seconds', min_views: 0 })
+
+      await enableRedundancyOnServer1()
+    })
+
+    it('Should still have 2 webseeds after 10 seconds', async function () {
+      this.timeout(40000)
+
+      await wait(10000)
+
+      try {
+        await checkContains(servers, 'http%3A%2F%2Flocalhost%3A9001')
+      } catch {
+        // Maybe a server deleted a redundancy in the scheduler
+        await wait(2000)
+
+        await checkContains(servers, 'http%3A%2F%2Flocalhost%3A9001')
+      }
+    })
+
+    it('Should stop server 1 and expire video redundancy', async function () {
+      this.timeout(40000)
+
+      killallServers([ servers[0] ])
+
+      await wait(10000)
+
+      await checkNotContains([ servers[1], servers[2] ], 'http%3A%2F%2Flocalhost%3A9001')
+    })
+
+    after(function () {
+      return killallServers([ servers[1], servers[2] ])
+    })
+  })
+
+  describe('Test file replacement', function () {
+    let video2Server2UUID: string
+    const strategy = 'recently-added'
+
+    before(async function () {
+      this.timeout(120000)
+
+      await runServers(strategy, { min_lifetime: '7 seconds', min_views: 0 })
+
+      await enableRedundancyOnServer1()
+
+      await waitJobs(servers)
+      await wait(5000)
+      await waitJobs(servers)
+
+      await check2Webseeds(strategy)
+      await checkStatsWith2Webseed(strategy)
+
+      const res = await uploadVideo(servers[ 1 ].url, servers[ 1 ].accessToken, { name: 'video 2 server 2' })
+      video2Server2UUID = res.body.video.uuid
+    })
+
+    it('Should cache video 2 webseed on the first video', async function () {
+      this.timeout(40000)
+      this.retries(3)
+
+      await waitJobs(servers)
+
+      await wait(7000)
+
+      await check1WebSeed(strategy, video1Server2UUID)
+      await check2Webseeds(strategy, video2Server2UUID)
     })
 
     after(function () {
diff --git a/server/tests/utils/server/servers.ts b/server/tests/utils/server/servers.ts
index 26ab4e1bb..fbfc83ca1 100644
--- a/server/tests/utils/server/servers.ts
+++ b/server/tests/utils/server/servers.ts
@@ -144,8 +144,8 @@ function runServer (serverNumber: number, configOverride?: Object) {
   })
 }
 
-async function reRunServer (server: ServerInfo) {
-  const newServer = await runServer(server.serverNumber)
+async function reRunServer (server: ServerInfo, configOverride?: any) {
+  const newServer = await runServer(server.serverNumber, configOverride)
   server.app = newServer.app
 
   return server
diff --git a/shared/models/redundancy/videos-redundancy.model.ts b/shared/models/redundancy/videos-redundancy.model.ts
index 436394c1e..a8c2743c1 100644
--- a/shared/models/redundancy/videos-redundancy.model.ts
+++ b/shared/models/redundancy/videos-redundancy.model.ts
@@ -3,17 +3,20 @@ export type VideoRedundancyStrategy = 'most-views' | 'trending' | 'recently-adde
 export type MostViewsRedundancyStrategy = {
   strategy: 'most-views'
   size: number
+  minLifetime: number
 }
 
 export type TrendingRedundancyStrategy = {
   strategy: 'trending'
   size: number
+  minLifetime: number
 }
 
 export type RecentlyAddedStrategy = {
   strategy: 'recently-added'
   size: number
   minViews: number
+  minLifetime: number
 }
 
 export type VideosRedundancy = MostViewsRedundancyStrategy | TrendingRedundancyStrategy | RecentlyAddedStrategy
diff --git a/support/doc/redundancy.md b/support/doc/redundancy.md
new file mode 100644
index 000000000..62c6365a9
--- /dev/null
+++ b/support/doc/redundancy.md
@@ -0,0 +1,46 @@
+# Redundancy
+
+A PeerTube instance can cache other PeerTube videos to improve bandwidth of popular videos or small instances.
+
+## How it works
+
+The instance administrator can choose between multiple redundancy strategies (cache trending videos or recently uploaded videos etc), set their maximum size and the minimum duplication lifetime.
+Then, they choose the instances they want to cache in `Manage follows -> Following` admin table.
+
+Videos are kept in the cache for at least `min_lifetime`, and then evicted when the cache is full.
+
+When PeerTube chooses a video to duplicate, it imports all the resolution files (to avoid consistency issues) using their magnet URI and put them in the `storage.videos` directory.
+Then it sends a `Create -> CacheFile` ActivityPub message to other federated instances. This new instance is injected as [WebSeed](https://github.com/Chocobozzz/PeerTube/blob/develop/FAQ.md#what-is-webseed) in the magnet URI by instances that received this ActivityPub message.
+
+## Stats
+ 
+See the `/api/v1/server/stats` endpoint. For example:
+
+```
+{
+  ...
+  "videosRedundancy": [
+    {
+      "totalUsed": 0,
+      "totalVideos": 0,
+      "totalVideoFiles": 0,
+      "strategy": "most-views",
+      "totalSize": 104857600
+    },
+    {
+      "totalUsed": 0,
+      "totalVideos": 0,
+      "totalVideoFiles": 0,
+      "strategy": "trending",
+      "totalSize": 104857600
+    },
+    {
+      "totalUsed": 0,
+      "totalVideos": 0,
+      "totalVideoFiles": 0,
+      "strategy": "recently-added",
+      "totalSize": 104857600
+    }
+  ]
+}
+```
\ No newline at end of file