diff --git a/ci/docker/Dockerfile.build.ubuntu_gpu_tensorrt b/ci/docker/Dockerfile.build.ubuntu_gpu_tensorrt
index 9556fee57f03..30b6b5d27176 100644
--- a/ci/docker/Dockerfile.build.ubuntu_gpu_tensorrt
+++ b/ci/docker/Dockerfile.build.ubuntu_gpu_tensorrt
@@ -16,7 +16,7 @@
 # specific language governing permissions and limitations
 # under the License.
 #
-# Dockerfile to run MXNet on Ubuntu 16.04 for CPU
+# Dockerfile to run MXNet on Ubuntu 18.04 for CPU
 
 FROM nvidia/cuda:10.2-cudnn7-devel-ubuntu18.04
 
diff --git a/ci/docker/Dockerfile.build.ubuntu_nightly_cpu b/ci/docker/Dockerfile.build.ubuntu_nightly_cpu
index b9c275e00919..65ea937c4582 100644
--- a/ci/docker/Dockerfile.build.ubuntu_nightly_cpu
+++ b/ci/docker/Dockerfile.build.ubuntu_nightly_cpu
@@ -16,9 +16,9 @@
 # specific language governing permissions and limitations
 # under the License.
 #
-# Dockerfile to build and run MXNet on Ubuntu 16.04 for CPU
+# Dockerfile to build and run MXNet on Ubuntu 18.04 for CPU
 
-FROM ubuntu:16.04
+FROM ubuntu:18.04
 
 WORKDIR /work/deps
 
diff --git a/ci/docker/Dockerfile.build.ubuntu_nightly_gpu b/ci/docker/Dockerfile.build.ubuntu_nightly_gpu
index 216e96fcebb8..c2d255bfe26c 100644
--- a/ci/docker/Dockerfile.build.ubuntu_nightly_gpu
+++ b/ci/docker/Dockerfile.build.ubuntu_nightly_gpu
@@ -16,9 +16,9 @@
 # specific language governing permissions and limitations
 # under the License.
 #
-# Dockerfile to run MXNet on Ubuntu 16.04 for CPU
+# Dockerfile to run MXNet on Ubuntu 18.04 for GPU
 
-FROM nvidia/cuda:10.1-devel-ubuntu16.04
+FROM nvidia/cuda:10.1-devel-ubuntu18.04
 
 WORKDIR /work/deps
 
@@ -67,10 +67,12 @@ RUN /work/ubuntu_tutorials.sh
 COPY install/ubuntu_nightly_tests.sh /work/
 RUN /work/ubuntu_nightly_tests.sh
 
-ENV CUDNN_VERSION=7.6.0.64
+ENV CUDA_VERSION=10.1.105
+ENV CUDNN_VERSION=7.6.5.32
 COPY install/ubuntu_cudnn.sh /work/
 RUN /work/ubuntu_cudnn.sh
 
+# Always last
 ARG USER_ID=0
 ARG GROUP_ID=0
 COPY install/ubuntu_adduser.sh /work/
diff --git a/ci/docker/Dockerfile.build.ubuntu_rat b/ci/docker/Dockerfile.build.ubuntu_rat
index 234d2e42e946..cc5ead675177 100644
--- a/ci/docker/Dockerfile.build.ubuntu_rat
+++ b/ci/docker/Dockerfile.build.ubuntu_rat
@@ -18,7 +18,7 @@
 #
 # Dockerfile to run the Apache RAT license check
 
-FROM ubuntu:16.04
+FROM ubuntu:18.04
 
 WORKDIR /work/deps
 
diff --git a/ci/docker/install/ubuntu_rat.sh b/ci/docker/install/ubuntu_rat.sh
index 917d0b683e28..d1e17c8e3182 100755
--- a/ci/docker/install/ubuntu_rat.sh
+++ b/ci/docker/install/ubuntu_rat.sh
@@ -21,7 +21,23 @@ set -ex
 
 echo "Install dependencies"
 apt-get update || true
-apt-get install -y subversion maven openjdk-8-jdk openjdk-8-jre
+apt-get install -y curl subversion openjdk-8-jdk openjdk-8-jre software-properties-common
+apt-add-repository ppa:webupd8team/java
+apt-get update
+
+# Installing maven 3.6.3 because default maven 3.7.x requires maven compiler >= 1.6
+url="https://mirror.olnevhost.net/pub/apache/maven/maven-3/3.6.3/binaries/apache-maven-3.6.3-bin.tar.gz"
+install_dir="/opt/maven"
+mkdir ${install_dir}
+curl -fsSL ${url} | tar zx --strip-components=1 -C ${install_dir}
+cat << EOF > /etc/profile.d/maven.sh
+#!/bin/sh
+export M2_HOME=${install_dir}
+export MAVEN_HOME=${install_dir}
+export PATH=${install_dir}/bin:${PATH}
+EOF
+source /etc/profile.d/maven.sh
+cat /etc/profile.d/maven.sh
 
 echo "download RAT"
 #svn co http://svn.apache.org/repos/asf/creadur/rat/trunk/
diff --git a/cpp-package/example/get_data.sh b/cpp-package/example/get_data.sh
index 77677c320c1b..fda69ce2f087 100755
--- a/cpp-package/example/get_data.sh
+++ b/cpp-package/example/get_data.sh
@@ -53,16 +53,12 @@ download () {
 
 # MNIST dataset from: http://yann.lecun.com/exdb/mnist/
 FILES=(
-    "http://yann.lecun.com/exdb/mnist/train-images-idx3-ubyte.gz"
-    "http://yann.lecun.com/exdb/mnist/train-labels-idx1-ubyte.gz"
-    "http://yann.lecun.com/exdb/mnist/t10k-images-idx3-ubyte.gz"
-    "http://yann.lecun.com/exdb/mnist/t10k-labels-idx1-ubyte.gz"
+    "https://web.archive.org/web/20160828233817/http://yann.lecun.com/exdb/mnist/train-images-idx3-ubyte.gz"
+    "https://web.archive.org/web/20160828233817/http://yann.lecun.com/exdb/mnist/train-labels-idx1-ubyte.gz"
+    "https://web.archive.org/web/20160828233817/http://yann.lecun.com/exdb/mnist/t10k-images-idx3-ubyte.gz"
+    "https://web.archive.org/web/20160828233817/http://yann.lecun.com/exdb/mnist/t10k-labels-idx1-ubyte.gz"
     "http://data.mxnet.io/data/mnist_train.csv.gz")
 
 for FILE in ${FILES[@]}; do
-    if curl --output /dev/null --silent --head --fail "$FILE"; then
-        download ${FILE}
-    else
-        download "https://web.archive.org/web/20160828233817/$FILE"
-    fi
+    download ${FILE}
 done