fix: performance improvements

package.json

@@ -14,7 +14,8 @@
     "release-minor": "aegir release --type minor --docs -t node",
     "release-major": "aegir release --type major --docs -t node",
     "coverage": "aegir coverage",
-    "coverage-publish": "aegir-coverage publish"
+    "coverage-publish": "aegir-coverage publish",
+    "sim": "node test/simulation/index.js"
   },
   "pre-push": [
     "lint",

src/constants.js

@@ -23,7 +23,7 @@ exports.PROVIDERS_VALIDITY = 24 * hour
 
 exports.PROVIDERS_CLEANUP_INTERVAL = hour
 
-exports.READ_MESSAGE_TIMEOUT = minute
+exports.READ_MESSAGE_TIMEOUT = 10 * second
 
 // The number of records that will be retrieved on a call to getMany()
 exports.GET_MANY_RECORD_COUNT = 16
@@ -34,16 +34,12 @@ exports.K = 20
 // Alpha is the concurrency for asynchronous requests
 exports.ALPHA = 3
 
-// Number of disjoint query paths to use
-// This is set to K/2 per the S/Kademlia paper
-exports.DISJOINT_PATHS = 10
-
 exports.maxMessageSize = 2 << 22 // 4MB
 
 exports.defaultRandomWalk = {
   enabled: true,
   queriesPerPeriod: 1,
   interval: 5 * minute,
-  timeout: 30 * second,
+  timeout: 10 * second,
   delay: 10 * second
 }

src/index.js

@@ -48,6 +48,7 @@ class KadDHT extends EventEmitter {
    * @param {Switch} sw libp2p-switch instance
    * @param {object} options DHT options
    * @param {number} options.kBucketSize k-bucket size (default 20)
+   * @param {number} options.concurrency alpha concurrency of queries (default 3)
    * @param {Datastore} options.datastore datastore (default MemoryDatastore)
    * @param {object} options.validators validators object with namespace as keys and function(key, record, callback)
    * @param {object} options.selectors selectors object with namespace as keys and function(key, records)
@@ -74,12 +75,25 @@ class KadDHT extends EventEmitter {
      */
     this.kBucketSize = options.kBucketSize || c.K
 
+    /**
+     * ALPHA concurrency at which each query path with run, defaults to 6
+     * @type {number}
+     */
+    this.concurrency = options.concurrency || c.ALPHA
+
+    /**
+     * Number of disjoint query paths to use
+     * This is set to `kBucketSize`/2 per the S/Kademlia paper
+     * @type {number}
+     */
+    this.disjointPaths = Math.ceil(this.kBucketSize / 2)
+
     /**
      * Number of closest peers to return on kBucket search, default 20
      *
      * @type {number}
      */
-    this.ncp = options.ncp || c.K
+    this.ncp = options.ncp || this.kBucketSize
 
     /**
      * The routing table.
@@ -321,7 +335,7 @@ class KadDHT extends EventEmitter {
       waterfall([
         (cb) => utils.convertBuffer(key, cb),
         (id, cb) => {
-          const rtp = this.routingTable.closestPeers(id, c.ALPHA)
+          const rtp = this.routingTable.closestPeers(id, this.kBucketSize)
 
           this._log('peers in rt: %d', rtp.length)
           if (rtp.length === 0) {
@@ -412,7 +426,7 @@ class KadDHT extends EventEmitter {
         return callback(err)
       }
 
-      const tablePeers = this.routingTable.closestPeers(id, c.ALPHA)
+      const tablePeers = this.routingTable.closestPeers(id, this.kBucketSize)
 
       const q = new Query(this, key, () => {
         // There is no distinction between the disjoint paths,
@@ -442,7 +456,7 @@ class KadDHT extends EventEmitter {
 
         waterfall([
           (cb) => utils.sortClosestPeers(Array.from(res.finalSet), id, cb),
-          (sorted, cb) => cb(null, sorted.slice(0, c.K))
+          (sorted, cb) => cb(null, sorted.slice(0, this.kBucketSize))
         ], callback)
       })
     })
@@ -527,6 +541,7 @@ class KadDHT extends EventEmitter {
   provide (key, callback) {
     this._log('provide: %s', key.toBaseEncodedString())
 
+    const errors = []
     waterfall([
       (cb) => this.providers.addProvider(key, this.peerInfo.id, cb),
       (cb) => this.getClosestPeers(key.buffer, cb),
@@ -536,10 +551,21 @@ class KadDHT extends EventEmitter {
 
         each(peers, (peer, cb) => {
           this._log('putProvider %s to %s', key.toBaseEncodedString(), peer.toB58String())
-          this.network.sendMessage(peer, msg, cb)
+          this.network.sendMessage(peer, msg, (err) => {
+            if (err) errors.push(err)
+            cb()
+          })
         }, cb)
       }
-    ], (err) => callback(err))
+    ], (err) => {
+      if (errors.length) {
+        // This should be infrequent. This means a peer we previously connected
+        // to failed to exchange the provide message. If getClosestPeers was an
+        // iterator, we could continue to pull until we announce to kBucketSize peers.
+        err = errcode(`Failed to provide to ${errors.length} of ${this.kBucketSize} peers`, 'ERR_SOME_PROVIDES_FAILED', { errors })
+      }
+      callback(err)
+    })
   }
 
   /**
@@ -613,7 +639,7 @@ class KadDHT extends EventEmitter {
       waterfall([
         (cb) => utils.convertPeerId(id, cb),
         (key, cb) => {
-          const peers = this.routingTable.closestPeers(key, c.ALPHA)
+          const peers = this.routingTable.closestPeers(key, this.kBucketSize)
 
           if (peers.length === 0) {
             return cb(errcode(new Error('Peer lookup failed'), 'ERR_LOOKUP_FAILED'))

src/private.js

@@ -82,7 +82,7 @@ module.exports = (dht) => ({
    * Try to fetch a given record by from the local datastore.
    * Returns the record iff it is still valid, meaning
    * - it was either authored by this node, or
-   * - it was receceived less than `MAX_RECORD_AGE` ago.
+   * - it was received less than `MAX_RECORD_AGE` ago.
    *
    * @param {Buffer} key
    * @param {function(Error, Record)} callback
@@ -171,7 +171,7 @@ module.exports = (dht) => ({
    *
    * @param {Buffer} key
    * @param {PeerId} peer
-   * @param {function(Error)} callback
+   * @param {function(Error, Array<PeerInfo>)} callback
    * @returns {void}
    *
    * @private
@@ -185,13 +185,12 @@ module.exports = (dht) => ({
 
       const out = msg.closerPeers
         .filter((pInfo) => !dht._isSelf(pInfo.id))
-        .map((pInfo) => dht.peerBook.put(pInfo))
 
       callback(null, out)
     })
   },
   /**
-   * Is the given peer id the peer id?
+   * Is the given peer id our PeerId?
    *
    * @param {PeerId} other
    * @returns {bool}
@@ -206,7 +205,7 @@ module.exports = (dht) => ({
    *
    * @param {PeerId} peer
    * @param {PeerId} target
-   * @param {function(Error)} callback
+   * @param {function(Error, Message)} callback
    * @returns {void}
    *
    * @private
@@ -522,7 +521,7 @@ module.exports = (dht) => ({
         }
       })
 
-      const peers = dht.routingTable.closestPeers(key.buffer, c.ALPHA)
+      const peers = dht.routingTable.closestPeers(key.buffer, dht.kBucketSize)
 
       timeout((cb) => query.run(peers, cb), providerTimeout)((err) => {
         query.stop()