From 3e285d6131b640078fae1517843804f3edc8618e Mon Sep 17 00:00:00 2001
From: wescoeur <ronan.abhamon@gmail.com>
Date: Wed, 6 Apr 2016 15:24:34 +0200
Subject: [PATCH] Search destination host per pool. (Performance mode)

---
 packages/xo-server-load-balancer/package.json |  2 +-
 .../src/performance-plan.js                   | 32 ++++++++++++++-----
 packages/xo-server-load-balancer/src/plan.js  | 16 ++++------
 packages/xo-server-load-balancer/src/utils.js | 13 --------
 4 files changed, 31 insertions(+), 32 deletions(-)

diff --git a/packages/xo-server-load-balancer/package.json b/packages/xo-server-load-balancer/package.json
index 204213c22..0e5091f7e 100644
--- a/packages/xo-server-load-balancer/package.json
+++ b/packages/xo-server-load-balancer/package.json
@@ -34,8 +34,8 @@
     "cron": "^1.1.0",
     "event-to-promise": "^0.6.0",
     "lodash.clonedeep": "^4.3.1",
-    "lodash.differenceby": "^4.2.1",
     "lodash.filter": "^4.2.0",
+    "lodash.find": "^4.3.0",
     "lodash.includes": "^4.1.0",
     "lodash.intersection": "^4.1.0",
     "lodash.map": "^4.2.0",
diff --git a/packages/xo-server-load-balancer/src/performance-plan.js b/packages/xo-server-load-balancer/src/performance-plan.js
index bbf4103b5..981a2e627 100644
--- a/packages/xo-server-load-balancer/src/performance-plan.js
+++ b/packages/xo-server-load-balancer/src/performance-plan.js
@@ -1,10 +1,21 @@
 import filter from 'lodash.filter'
+import find from 'lodash.find'
 
 import Plan from './plan'
-import {
-  debug,
-  searchObject
-} from './utils'
+import { debug } from './utils'
+
+// Compare a list of objects and give the best.
+function searchBestObject (objects, fun) {
+  let object = objects[0]
+
+  for (let i = 1; i < objects.length; i++) {
+    if (fun(object, objects[i]) > 0) {
+      object = objects[i]
+    }
+  }
+
+  return object
+}
 
 // ===================================================================
 
@@ -74,11 +85,16 @@ export default class PerformancePlan extends Plan {
     const xapiSrc = this.xo.getXapi(exceededHost)
     let optimizationsCount = 0
 
+    const searchFunction = (a, b) => hostsAverages[b.id].cpu - hostsAverages[a.id].cpu
+
     for (const vm of vms) {
-      // Search host with lower cpu usage.
-      const destination = searchObject(hosts, (a, b) =>
-        hostsAverages[b.id].cpu - hostsAverages[a.id].cpu
-      )
+      // Search host with lower cpu usage in the same pool first. In other pool if necessary.
+      let destination = searchBestObject(find(hosts, host => host.$poolId === vm.$poolId), searchFunction)
+
+      if (!destination) {
+        destination = searchBestObject(hosts, searchFunction)
+      }
+
       const destinationAverages = hostsAverages[destination.id]
       const vmAverages = vmsAverages[vm.id]
 
diff --git a/packages/xo-server-load-balancer/src/plan.js b/packages/xo-server-load-balancer/src/plan.js
index d4b240fe1..2f24b0ce9 100644
--- a/packages/xo-server-load-balancer/src/plan.js
+++ b/packages/xo-server-load-balancer/src/plan.js
@@ -1,4 +1,3 @@
-import differenceBy from 'lodash.differenceby'
 import filter from 'lodash.filter'
 import includes from 'lodash.includes'
 import { default as mapToArray } from 'lodash.map'
@@ -188,15 +187,12 @@ export default class Plan {
 
   // Compute hosts for each pool. They can change over time.
   _getHosts () {
-    return differenceBy(
-      filter(this.xo.getObjects(), object => {
-        object.type === 'host' &&
-        includes(this._poolIds, object.$poolId) &&
-        object.power_state !== 'Halted'
-      }),
-      this._excludedHosts,
-      val => val.id || val
-    )
+    return filter(this.xo.getObjects(), object => (
+      object.type === 'host' &&
+      includes(this._poolIds, object.$poolId) &&
+      object.power_state !== 'Halted' &&
+      !includes(this._excludedHosts, object.id)
+    ))
   }
 
   async _getVms (hostId) {
diff --git a/packages/xo-server-load-balancer/src/utils.js b/packages/xo-server-load-balancer/src/utils.js
index d2eca97e1..f7894a639 100644
--- a/packages/xo-server-load-balancer/src/utils.js
+++ b/packages/xo-server-load-balancer/src/utils.js
@@ -11,16 +11,3 @@ export const EXECUTION_DELAY = 1
 export const debug = LOAD_BALANCER_DEBUG
   ? str => console.log(`[load-balancer]${str}`)
   : noop
-
-// Compare a list of objects and give the best.
-export function searchObject (objects, fun) {
-  let object = objects[0]
-
-  for (let i = 1; i < objects.length; i++) {
-    if (fun(object, objects[i]) > 0) {
-      object = objects[i]
-    }
-  }
-
-  return object
-}