diff --git a/base/Dockerfile b/base/Dockerfile
index dec673e..c4263ae 100644
--- a/base/Dockerfile
+++ b/base/Dockerfile
@@ -1,47 +1,55 @@
-FROM debian:9
+# Base image: Debian-12
+FROM debian:12
 
-MAINTAINER Ivan Ermilov <ivan.s.ermilov@gmail.com>
-MAINTAINER Giannis Mouchakis <gmouchakis@iit.demokritos.gr>
-
-RUN apt-get update && DEBIAN_FRONTEND=noninteractive apt-get install -y --no-install-recommends \
-      openjdk-8-jdk \
-      net-tools \
-      curl \
-      netcat \
-      gnupg \
-      libsnappy-dev \
-    && rm -rf /var/lib/apt/lists/*
+# Update local package index, upgrade packages and install required packages. 
+RUN apt-get update && apt-get -y upgrade && DEBIAN_FRONTEND=noninteractive apt-get install -y --no-install-recommends \
+	openjdk-8-jdk \
+	net-tools \
+	curl \
+	netcat \
+	gnupg \
+	libsnappy-dev \
+	&& rm -rf /var/lib/apt/lists/*
       
+# Set Java env
 ENV JAVA_HOME=/usr/lib/jvm/java-8-openjdk-amd64/
 
+# Download Hadoop Keys
 RUN curl -O https://dist.apache.org/repos/dist/release/hadoop/common/KEYS
 
+# Import keys
 RUN gpg --import KEYS
 
-ENV HADOOP_VERSION 3.2.1
+# Set hadoop version & URL
+ENV HADOOP_VERSION 3.3.6
 ENV HADOOP_URL https://www.apache.org/dist/hadoop/common/hadoop-$HADOOP_VERSION/hadoop-$HADOOP_VERSION.tar.gz
 
+# Download hadoop and signature, verify with gpg, extract hadoop-ver.tar.hz into /opt and remove hadoop-ver.tar.gz
 RUN set -x \
-    && curl -fSL "$HADOOP_URL" -o /tmp/hadoop.tar.gz \
-    && curl -fSL "$HADOOP_URL.asc" -o /tmp/hadoop.tar.gz.asc \
-    && gpg --verify /tmp/hadoop.tar.gz.asc \
-    && tar -xvf /tmp/hadoop.tar.gz -C /opt/ \
-    && rm /tmp/hadoop.tar.gz*
+	&& curl -fSL "$HADOOP_URL" -o /tmp/hadoop.tar.gz \
+	&& curl -fSL "$HADOOP_URL.asc" -o /tmp/hadoop.tar.gz.asc \
+	&& gpg --verify /tmp/hadoop.tar.gz.asc \
+	&& tar -xvf /tmp/hadoop.tar.gz -C /opt/ \
+	&& rm /tmp/hadoop.tar.gz*
 
+# Establish symobolic link in /etc/hadoop for /opt/hadoop-$HADOOP_VERSION/etc/hadoop
 RUN ln -s /opt/hadoop-$HADOOP_VERSION/etc/hadoop /etc/hadoop
 
-RUN mkdir /opt/hadoop-$HADOOP_VERSION/logs
-
-RUN mkdir /hadoop-data
+# Make logs dir and data dir
+RUN mkdir /opt/hadoop-$HADOOP_VERSION/logs /hadoop-data
 
+# Set env
 ENV HADOOP_HOME=/opt/hadoop-$HADOOP_VERSION
 ENV HADOOP_CONF_DIR=/etc/hadoop
 ENV MULTIHOMED_NETWORK=1
 ENV USER=root
 ENV PATH $HADOOP_HOME/bin/:$PATH
 
+# Copy entrypoint.sh to container
 ADD entrypoint.sh /entrypoint.sh
 
+# Make entrypoint.sh executable
 RUN chmod a+x /entrypoint.sh
 
+# Specify entrypoint
 ENTRYPOINT ["/entrypoint.sh"]