diff --git a/core/ArchiveProcessor/FixedSiteIds.php b/core/ArchiveProcessor/FixedSiteIds.php
index 5bf54ccc3f9..8e70f9b18ae 100644
--- a/core/ArchiveProcessor/FixedSiteIds.php
+++ b/core/ArchiveProcessor/FixedSiteIds.php
@@ -20,7 +20,9 @@ class FixedSiteIds
 
     public function __construct($websiteIds)
     {
-        $this->siteIds = $websiteIds;
+        if (!empty($websiteIds)) {
+            $this->siteIds = $websiteIds;
+        }
     }
 
     /**
@@ -40,7 +42,13 @@ public function getNumSites()
      */
     public function getNumProcessedWebsites()
     {
-        return $this->index + 1;
+        $numProcessed = $this->index + 1;
+
+        if ($numProcessed > $this->getNumSites()) {
+            return $this->getNumSites();
+        }
+
+        return $numProcessed;
     }
 
     public function getNextSiteId()
diff --git a/core/ArchiveProcessor/SharedSiteIds.php b/core/ArchiveProcessor/SharedSiteIds.php
index 84d6b6dcff5..0deeda80bb0 100644
--- a/core/ArchiveProcessor/SharedSiteIds.php
+++ b/core/ArchiveProcessor/SharedSiteIds.php
@@ -20,9 +20,14 @@ class SharedSiteIds
 {
     private $siteIds = array();
     private $currentSiteId;
+    private $done = false;
 
     public function __construct($websiteIds)
     {
+        if (empty($websiteIds)) {
+            $websiteIds = array();
+        }
+
         $self = $this;
         $this->siteIds = $this->runExclusive(function () use ($self, $websiteIds) {
             // if there are already sites to be archived registered, prefer the list of existing archive, meaning help
@@ -56,6 +61,10 @@ public function getNumSites()
      */
     public function getNumProcessedWebsites()
     {
+        if ($this->done) {
+            return $this->getNumSites();
+        }
+
         if (empty($this->currentSiteId)) {
             return 0;
         }
@@ -103,6 +112,7 @@ public function getAllSiteIdsToArchive()
     private function runExclusive($closure)
     {
         $process = new Process('archive.sharedsiteids');
+
         while ($process->isRunning() && $process->getSecondsSinceCreation() < 5) {
             // wait max 5 seconds, such an operation should not take longer
             usleep(25);
@@ -145,6 +155,10 @@ public function getNextSiteId()
             return $nextSiteId;
         });
 
+        if (is_null($this->currentSiteId)) {
+            $this->done = true;
+        }
+
         return $this->currentSiteId;
     }
 
diff --git a/core/CronArchive.php b/core/CronArchive.php
index 2c5cc4fd964..f14545ee01a 100644
--- a/core/CronArchive.php
+++ b/core/CronArchive.php
@@ -284,7 +284,8 @@ public function run()
 
             // Also reprocess when day has ended since last run
             if ($dayHasEndedMustReprocess
-                && !$this->hasBeenProcessedSinceMidnight($idsite, $lastTimestampWebsiteProcessedDay) // it might have reprocessed for that day by another cron
+                // it might have reprocessed for that day by another cron
+                && !$this->hasBeenProcessedSinceMidnight($idsite, $lastTimestampWebsiteProcessedDay)
                 && !$existingArchiveIsValid) {
                 $skipDayArchive = false;
             }
diff --git a/tests/PHPUnit/Core/ArchiveProcessor/FixedSiteIdsTest.php b/tests/PHPUnit/Core/ArchiveProcessor/FixedSiteIdsTest.php
new file mode 100644
index 00000000000..6d0c6cf78eb
--- /dev/null
+++ b/tests/PHPUnit/Core/ArchiveProcessor/FixedSiteIdsTest.php
@@ -0,0 +1,55 @@
+<?php
+/**
+ * Piwik - Open source web analytics
+ *
+ * @link http://piwik.org
+ * @license http://www.gnu.org/licenses/gpl-3.0.html GPL v3 or later
+ */
+
+use \Piwik\ArchiveProcessor\FixedSiteIds;
+
+/**
+ * @group Core
+ */
+class FixedSiteIdsTest extends PHPUnit_Framework_TestCase
+{
+    /**
+     * @var FixedSiteIds
+     */
+    private $fixedSiteIds;
+
+    public function setUp()
+    {
+        $this->fixedSiteIds = new FixedSiteIds(array(1,2,5,9));
+    }
+
+    public function test_construct_withEmptyValue()
+    {
+        $siteIds = new FixedSiteIds(null);
+        $this->assertEquals(0, $siteIds->getNumSites());
+        $this->assertNull($siteIds->getNextSiteId());
+    }
+
+    public function test_getNumSites()
+    {
+        $this->assertEquals(4, $this->fixedSiteIds->getNumSites());
+    }
+
+    public function test_getNumProcessedWebsites_getNextSiteId()
+    {
+        $this->assertEquals(0, $this->fixedSiteIds->getNumProcessedWebsites());
+        $this->assertEquals(1, $this->fixedSiteIds->getNextSiteId());
+        $this->assertEquals(1, $this->fixedSiteIds->getNumProcessedWebsites());
+        $this->assertEquals(2, $this->fixedSiteIds->getNextSiteId());
+        $this->assertEquals(2, $this->fixedSiteIds->getNumProcessedWebsites());
+        $this->assertEquals(5, $this->fixedSiteIds->getNextSiteId());
+        $this->assertEquals(3, $this->fixedSiteIds->getNumProcessedWebsites());
+        $this->assertEquals(9, $this->fixedSiteIds->getNextSiteId());
+        $this->assertEquals(4, $this->fixedSiteIds->getNumProcessedWebsites());
+
+        $this->assertNull($this->fixedSiteIds->getNextSiteId());
+        $this->assertEquals(4, $this->fixedSiteIds->getNumProcessedWebsites());
+    }
+
+
+}
\ No newline at end of file
diff --git a/tests/PHPUnit/Core/ArchiveProcessor/SharedSiteIdsTest.php b/tests/PHPUnit/Core/ArchiveProcessor/SharedSiteIdsTest.php
new file mode 100644
index 00000000000..e8df2c9d233
--- /dev/null
+++ b/tests/PHPUnit/Core/ArchiveProcessor/SharedSiteIdsTest.php
@@ -0,0 +1,108 @@
+<?php
+/**
+ * Piwik - Open source web analytics
+ *
+ * @link http://piwik.org
+ * @license http://www.gnu.org/licenses/gpl-3.0.html GPL v3 or later
+ */
+
+use \Piwik\ArchiveProcessor\SharedSiteIds;
+
+/**
+ * @group Core
+ */
+class SharedSiteIdsTest extends PHPUnit_Framework_TestCase
+{
+    /**
+     * @var SharedSiteIds
+     */
+    private $sharedSiteIds;
+
+    public function setUp()
+    {
+        $this->sharedSiteIds = new SharedSiteIds(array(1,2,5,9));
+    }
+
+    public function tearDown()
+    {
+        $this->sharedSiteIds->setSiteIdsToArchive(array());
+    }
+
+    public function test_construct_withEmptyValue()
+    {
+        $this->sharedSiteIds->setSiteIdsToArchive(array());
+
+        $siteIds = new SharedSiteIds(null);
+        $this->assertEquals(0, $siteIds->getNumSites());
+        $this->assertNull($siteIds->getNextSiteId());
+    }
+
+    public function test_isSupported()
+    {
+        $this->assertTrue(SharedSiteIds::isSupported());
+    }
+
+    public function test_getNumSites()
+    {
+        $this->assertEquals(4, $this->sharedSiteIds->getNumSites());
+    }
+
+    public function test_getAllSiteIdsToArchive()
+    {
+        $this->assertEquals(array(1,2,5,9), $this->sharedSiteIds->getAllSiteIdsToArchive());
+    }
+
+    public function test_getNumProcessedWebsites_getNextSiteId()
+    {
+        $this->assertEquals(0, $this->sharedSiteIds->getNumProcessedWebsites());
+
+        $this->assertEquals(1, $this->sharedSiteIds->getNextSiteId());
+        $this->assertEquals(1, $this->sharedSiteIds->getNumProcessedWebsites());
+
+        $this->assertEquals(2, $this->sharedSiteIds->getNextSiteId());
+        $this->assertEquals(2, $this->sharedSiteIds->getNumProcessedWebsites());
+
+        $this->assertEquals(5, $this->sharedSiteIds->getNextSiteId());
+        $this->assertEquals(3, $this->sharedSiteIds->getNumProcessedWebsites());
+
+        $this->assertEquals(9, $this->sharedSiteIds->getNextSiteId());
+        $this->assertEquals(4, $this->sharedSiteIds->getNumProcessedWebsites());
+
+        $this->assertNull($this->sharedSiteIds->getNextSiteId());
+        $this->assertEquals(4, $this->sharedSiteIds->getNumProcessedWebsites());
+    }
+
+    public function test_usingMultipleSharedSiteIds()
+    {
+        $second = new SharedSiteIds(array(7,9,11,6,1,2));
+
+        // should ignore his queue and help processing the existing queue
+        $this->assertEquals(4, $second->getNumSites());
+        $this->assertEquals(4, $this->sharedSiteIds->getNumSites());
+
+        $this->assertEquals(array(1,2,5,9), $second->getAllSiteIdsToArchive());
+        $this->assertEquals(1, $second->getNextSiteId());
+        $this->assertEquals(1, $second->getNumProcessedWebsites());
+
+        $this->assertEquals(array(2,5,9), $this->sharedSiteIds->getAllSiteIdsToArchive());
+        $this->assertEquals(2, $this->sharedSiteIds->getNextSiteId());
+        $this->assertEquals(2, $this->sharedSiteIds->getNumProcessedWebsites());
+
+        $this->assertEquals(array(5,9), $second->getAllSiteIdsToArchive());
+        $this->assertEquals(5, $second->getNextSiteId());
+        $this->assertEquals(3, $second->getNumProcessedWebsites());
+
+        $this->assertEquals(array(9), $this->sharedSiteIds->getAllSiteIdsToArchive());
+        $this->assertEquals(9, $this->sharedSiteIds->getNextSiteId());
+        $this->assertEquals(4, $this->sharedSiteIds->getNumProcessedWebsites());
+
+        $this->assertNull($second->getNextSiteId());
+        $this->assertEquals(4, $second->getNumProcessedWebsites());
+        $this->assertEquals(array(), $second->getAllSiteIdsToArchive());
+
+        $this->assertNull($this->sharedSiteIds->getNextSiteId());
+        $this->assertEquals(4, $this->sharedSiteIds->getNumProcessedWebsites());
+        $this->assertEquals(array(), $this->sharedSiteIds->getAllSiteIdsToArchive());
+    }
+
+}
\ No newline at end of file