diff --git a/.travis.yml b/.travis.yml
index 024b8097b877..42139a1752fe 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -22,7 +22,7 @@ script:
 
   - echo 'makeZipFile' && echo -en 'travis_fold:start:script.makeZipFile\\r'
   - npm run clean
-  - npm run makeZipFile
+  - npm run makeZipFile -- --concurrency 2
   - npm pack
   - echo -en 'travis_fold:end:script.makeZipFile\\r'
 
diff --git a/CHANGES.md b/CHANGES.md
index e8f7634f891e..8dc9ee882d44 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -14,13 +14,16 @@ Change Log
    * `Scene/PerspectiveFrustum` is deprecated and will be removed in 1.38. Use `Core/PerspectiveFrustum`.
    * `Scene/PerspectiveOffCenterFrustum` is deprecated and will be removed in 1.38. Use `Core/PerspectiveOffCenterFrustum`.
 * Added ability to show tile urls in the 3D Tiles Inspector. [#5592](https://github.com/AnalyticalGraphicsInc/cesium/pull/5592)
+* Fixed issue where composite 3D Tiles that contained instanced 3D Tiles with an external model reference would fail to download the model.
 * Added behavior to `Cesium3DTilesInspector` that selects the first tileset hovered over if no tilest is specified. [#5139](https://github.com/AnalyticalGraphicsInc/cesium/issues/5139)
 * Added ability to provide a `width` and `height` to `scene.pick`. [#5602](https://github.com/AnalyticalGraphicsInc/cesium/pull/5602)
+* Added setter for `GeoJsonDataSource.name` to specify a name for the datasource [#5653](https://github.com/AnalyticalGraphicsInc/cesium/issues/5653)
 * Fixed issue where scene would blink when labels were added. [#5537](https://github.com/AnalyticalGraphicsInc/cesium/issues/5537)
 * Fixed label positioning when height reference changes [#5609](https://github.com/AnalyticalGraphicsInc/cesium/issues/5609)
 * Fixed crash when using the `Cesium3DTilesInspectorViewModel` and removing a tileset [#5607](https://github.com/AnalyticalGraphicsInc/cesium/issues/5607)
 * Fixed polygon outline in Polygon Sandcastle demo [#5642](https://github.com/AnalyticalGraphicsInc/cesium/issues/5642)
 * Fixed label positioning when using `HeightReference.CLAMP_TO_GROUND` and no position [#5648](https://github.com/AnalyticalGraphicsInc/cesium/pull/5648)
+* Updated `Billboard`, `Label` and `PointPrimitive` constructors to clone `NearFarScale` parameters [#5654](https://github.com/AnalyticalGraphicsInc/cesium/pull/5654)
 * Added `FrustumGeometry` and `FrustumOutlineGeometry`. [#5649](https://github.com/AnalyticalGraphicsInc/cesium/pull/5649)
 * Added an `options` parameter to the constructors of `PerspectiveFrustum`, `PerspectiveOffCenterFrustum`, `OrthographicFrustum`, and `OrthographicOffCenterFrustum` to set properties. [#5649](https://github.com/AnalyticalGraphicsInc/cesium/pull/5649)
 * Added `ClassificationPrimitive` which defines a volume and draws the intersection of the volume and terrain or 3D Tiles. [#5625](https://github.com/AnalyticalGraphicsInc/cesium/pull/5625)
diff --git a/Source/DataSources/GeoJsonDataSource.js b/Source/DataSources/GeoJsonDataSource.js
index 2123486fcb1c..854760323b76 100644
--- a/Source/DataSources/GeoJsonDataSource.js
+++ b/Source/DataSources/GeoJsonDataSource.js
@@ -683,13 +683,19 @@ define([
 
     defineProperties(GeoJsonDataSource.prototype, {
         /**
-         * Gets a human-readable name for this instance.
+         * Gets or sets a human-readable name for this instance.
          * @memberof GeoJsonDataSource.prototype
          * @type {String}
          */
         name : {
             get : function() {
                 return this._name;
+            },
+            set : function(value) {
+                if (this._name !== value) {
+                    this._name = value;
+                    this._changed.raiseEvent(this);
+                }
             }
         },
         /**
diff --git a/Source/Scene/Instanced3DModel3DTileContent.js b/Source/Scene/Instanced3DModel3DTileContent.js
index 8eeaac92317e..429f51d35200 100644
--- a/Source/Scene/Instanced3DModel3DTileContent.js
+++ b/Source/Scene/Instanced3DModel3DTileContent.js
@@ -311,6 +311,10 @@ define([
 
         if (gltfFormat === 0) {
             var gltfUrl = getStringFromTypedArray(gltfView);
+
+            // We need to remove padding from the end of the model URL in case this tile was part of a composite tile.
+            // This removes all white space and null characters from the end of the string.
+            gltfUrl = gltfUrl.replace(/[\s\0]+$/, '');
             collectionOptions.url = getAbsoluteUri(joinUrls(getBaseUri(content._url, true), gltfUrl));
         } else {
             collectionOptions.gltf = gltfView;
diff --git a/Source/Scene/Model.js b/Source/Scene/Model.js
index 6924b9387db1..0bd2a4d638bf 100644
--- a/Source/Scene/Model.js
+++ b/Source/Scene/Model.js
@@ -4770,6 +4770,11 @@ define([
             destroy(this._rendererResources.vertexArrays);
         }
 
+        if (defined(this._removeUpdateHeightCallback)) {
+            this._removeUpdateHeightCallback();
+            this._removeUpdateHeightCallback = undefined;
+        }
+
         this._rendererResources = undefined;
         this._cachedRendererResources = this._cachedRendererResources && this._cachedRendererResources.release();
 
diff --git a/Specs/Data/Cesium3DTiles/Composite/CompositeOfInstanced/box.glb b/Specs/Data/Cesium3DTiles/Composite/CompositeOfInstanced/box.glb
new file mode 100644
index 000000000000..2bde3c4ee98e
Binary files /dev/null and b/Specs/Data/Cesium3DTiles/Composite/CompositeOfInstanced/box.glb differ
diff --git a/Specs/Data/Cesium3DTiles/Composite/CompositeOfInstanced/compositeOfInstanced.cmpt b/Specs/Data/Cesium3DTiles/Composite/CompositeOfInstanced/compositeOfInstanced.cmpt
new file mode 100644
index 000000000000..99f84f85f092
Binary files /dev/null and b/Specs/Data/Cesium3DTiles/Composite/CompositeOfInstanced/compositeOfInstanced.cmpt differ
diff --git a/Specs/Data/Cesium3DTiles/Composite/CompositeOfInstanced/tileset.json b/Specs/Data/Cesium3DTiles/Composite/CompositeOfInstanced/tileset.json
new file mode 100644
index 000000000000..9609546a000c
--- /dev/null
+++ b/Specs/Data/Cesium3DTiles/Composite/CompositeOfInstanced/tileset.json
@@ -0,0 +1,29 @@
+{
+  "asset": {
+    "version": "0.0"
+  },
+  "properties": {
+    "Height": {
+      "minimum": 20,
+      "maximum": 20
+    }
+  },
+  "geometricError": 70,
+  "root": {
+    "refine": "ADD",
+    "boundingVolume": {
+      "region": [
+        -1.3197004795898053,
+        0.6988582109,
+        -1.3196595204101946,
+        0.6988897891,
+        0,
+        30
+      ]
+    },
+    "geometricError": 0,
+    "content": {
+      "url": "compositeOfInstanced.cmpt"
+    }
+  }
+}
diff --git a/Specs/DataSources/GeoJsonDataSourceSpec.js b/Specs/DataSources/GeoJsonDataSourceSpec.js
index a19097e85205..18fd511998bd 100644
--- a/Specs/DataSources/GeoJsonDataSourceSpec.js
+++ b/Specs/DataSources/GeoJsonDataSourceSpec.js
@@ -279,6 +279,19 @@ defineSuite([
         expect(dataSource.show).toBe(true);
     });
 
+    it('setting name raises changed event', function() {
+        var dataSource = new GeoJsonDataSource();
+
+        var spy = jasmine.createSpy('changedEvent');
+        dataSource.changedEvent.addEventListener(spy);
+
+        var newName = 'chester';
+        dataSource.name = newName;
+        expect(dataSource.name).toEqual(newName);
+        expect(spy.calls.count()).toEqual(1);
+        expect(spy).toHaveBeenCalledWith(dataSource);
+    });
+
     it('show sets underlying entity collection show.', function() {
         var dataSource = new GeoJsonDataSource();
 
diff --git a/Specs/Scene/Composite3DTileContentSpec.js b/Specs/Scene/Composite3DTileContentSpec.js
index 103ad89ac774..2f0be37c6bed 100644
--- a/Specs/Scene/Composite3DTileContentSpec.js
+++ b/Specs/Scene/Composite3DTileContentSpec.js
@@ -20,12 +20,13 @@ defineSuite([
 
     var compositeUrl = './Data/Cesium3DTiles/Composite/Composite/';
     var compositeOfComposite = './Data/Cesium3DTiles/Composite/CompositeOfComposite/';
+    var compositeOfInstanced = './Data/Cesium3DTiles/Composite/compositeOfInstanced/';
 
     beforeAll(function() {
         scene = createScene();
         // One item in each data set is always located in the center, so point the camera there
         var center = Cartesian3.fromRadians(centerLongitude, centerLatitude);
-        scene.camera.lookAt(center, new HeadingPitchRange(0.0, -1.57, 30.0));
+        scene.camera.lookAt(center, new HeadingPitchRange(0.0, -1.57, 26.0));
     });
 
     afterAll(function() {
@@ -121,6 +122,10 @@ defineSuite([
         return Cesium3DTilesTester.loadTileset(scene, compositeOfComposite).then(expectRenderComposite);
     });
 
+    it('renders multiple instanced tilesets', function() {
+        return Cesium3DTilesTester.loadTileset(scene, compositeOfInstanced).then(expectRenderComposite);
+    });
+
     it('destroys', function() {
         return Cesium3DTilesTester.tileDestroys(scene, compositeUrl);
     });
diff --git a/Specs/Scene/ModelSpec.js b/Specs/Scene/ModelSpec.js
index 87f7a76c5346..c7dd2dfec270 100644
--- a/Specs/Scene/ModelSpec.js
+++ b/Specs/Scene/ModelSpec.js
@@ -2521,6 +2521,23 @@ defineSuite([
             });
         });
 
+        it('removes the callback on destroy', function() {
+            scene.globe = createMockGlobe();
+            return loadModelJson(texturedBoxModel.gltf, {
+                heightReference : HeightReference.CLAMP_TO_GROUND,
+                position : Cartesian3.fromDegrees(-72.0, 40.0),
+                scene : scene,
+                show : true
+            }).then(function(model) {
+                expect(scene.globe.callback).toBeDefined();
+                scene.renderForSpecs();
+
+                primitives.remove(model);
+                scene.renderForSpecs();
+                expect(scene.globe.callback).toBeUndefined();
+            });
+        });
+
         it('changing the terrain provider', function() {
             scene.globe = createMockGlobe();
             return loadModelJson(texturedBoxModel.gltf, {
@@ -2566,5 +2583,4 @@ defineSuite([
             });
         });
     });
-
 }, 'WebGL');
diff --git a/gulpfile.js b/gulpfile.js
index b46c2eb1999c..6be3722bd14b 100644
--- a/gulpfile.js
+++ b/gulpfile.js
@@ -46,8 +46,10 @@ var noDevelopmentGallery = taskName === 'release' || taskName === 'makeZipFile';
 var buildingRelease = noDevelopmentGallery;
 var minifyShaders = taskName === 'minify' || taskName === 'minifyRelease' || taskName === 'release' || taskName === 'makeZipFile' || taskName === 'buildApps';
 
-//travis reports 32 cores but only has 3GB of memory, which causes the VM to run out.  Limit to 8 cores instead.
-var concurrency = Math.min(os.cpus().length, 8);
+var concurrency = yargs.argv.concurrency;
+if (!concurrency) {
+    concurrency = os.cpus().length;
+}
 
 //Since combine and minify run in parallel already, split concurrency in half when building both.
 //This can go away when gulp 4 comes out because it allows for synchronous tasks.