diff --git a/dockerfiles/Dockerfile b/dockerfiles/Dockerfile
index 698ad34..01e5055 100644
--- a/dockerfiles/Dockerfile
+++ b/dockerfiles/Dockerfile
@@ -1,31 +1,34 @@
 FROM openjdk:12
 
 # Java global config
 ARG MAX_RAM=2800G
 ENV JAVA_TOOL_OPTIONS                                                   \
     -Xmx${MAX_RAM} -XX:PretenureSizeThreshold=512M -XX:MaxNewSize=4G    \
     -XX:+UseLargePages -XX:+UseTransparentHugePages -XX:+UseNUMA        \
     -XX:+UseTLAB -XX:+ResizeTLAB                                        \
     -Dlogback.configurationFile=configuration/logback.xml
 
+# Monitoring
+RUN yum install -y time
+
 # Download third party binaries and dependencies
 WORKDIR /srv/softwareheritage/graph/lib
 
 RUN curl -O http://webgraph.di.unimi.it/webgraph-big-3.5.1-bin.tar.gz
 RUN tar xvfz webgraph-big-3.5.1-bin.tar.gz
 RUN cp webgraph-big-3.5.1/webgraph-big-3.5.1.jar .
 
 RUN curl -O http://webgraph.di.unimi.it/webgraph-big-deps.tar.gz
 RUN tar xvfz webgraph-big-deps.tar.gz
 
 RUN curl -O http://law.di.unimi.it/software/download/law-2.5.2-bin.tar.gz
 RUN tar xvfz law-2.5.2-bin.tar.gz
 RUN cp law-2.5.2/law-2.5.2.jar .
 
 # Add user files
 WORKDIR /srv/softwareheritage/graph/app
 COPY configuration configuration/
 COPY scripts scripts/
 
 # Default dir
 WORKDIR /srv/softwareheritage/graph
diff --git a/dockerfiles/scripts/compress_graph.sh b/dockerfiles/scripts/compress_graph.sh
index edafadb..4db32c6 100755
--- a/dockerfiles/scripts/compress_graph.sh
+++ b/dockerfiles/scripts/compress_graph.sh
@@ -1,102 +1,102 @@
 #!/bin/bash
 
 usage() {
     echo "Usage: compress_graph.sh --lib <LIB_DIR> --input <GRAPH_BASEPATH>"
     echo "Options:"
     echo "  -o, --outdir <OUT_DIR>    (Default: GRAPH_DIR/compressed)"
     echo "  -t, --tmp <TMP_DIR>       (Default: OUT_DIR/tmp)"
     echo "  --stdout  <STDOUT_LOG>    (Default: OUT_DIR/stdout)"
     echo "  --stderr  <STDERR_LOG>    (Default: OUT_DIR/stderr)"
     echo "  --batch-size <BATCH_SIZE> (Default: 10^6): WebGraph internals"
     exit 1
 }
 
 graph_path=""
 out_dir=""
 lib_dir=""
 stdout_file=""
 stderr_file=""
 batch_size=1000000
 while (( "$#" )); do
     case "$1" in
         -i|--input)   shift; graph_path=$1 ;;
         -o|--outdir)  shift; out_dir=$1 ;;
         -l|--lib)     shift; lib_dir=$1 ;;
         -t|--tmp)     shift; tmp_dir=$1 ;;
         --stdout)     shift; stdout_file=$1 ;;
         --stderr)     shift; stderr_file=$1 ;;
         --batch-size) shift; batch_size=$1 ;;
         *) usage ;;
     esac
     shift
 done
 
 if [[ -z "$graph_path" || ! -d "$lib_dir" ]]; then
     usage
 fi
 if [ -z "$out_dir" ] ; then
     out_dir="$(dirname $graph_path)/compressed"
 fi
 if [ -z "$tmp_dir" ] ; then
     tmp_dir="${out_dir}/tmp"
 fi
 if [ -z "$stdout_file" ] ; then
     stdout_file="${out_dir}/stdout"
 fi
 if [ -z "$stderr_file" ] ; then
     stderr_file="${out_dir}/stderr"
 fi
 
 dataset=$(basename $graph_path)
 compr_graph_path="${out_dir}/${dataset}"
 
 test -d "$out_dir" || mkdir -p "$out_dir"
 test -d "$tmp_dir" || mkdir -p "$tmp_dir"
 
 java_cmd () {
-    java -cp $lib_dir/'*' $*
+    /usr/bin/time -v java -cp $lib_dir/'*' $*
 }
 
 {
     # Build a function (MPH) that maps node names to node numbers in
     # lexicographic order (output: .mph)
     java_cmd it.unimi.dsi.sux4j.mph.GOVMinimalPerfectHashFunction       \
         --zipped $compr_graph_path.mph --temp-dir $tmp_dir              \
         $graph_path.nodes.csv.gz                                        &&
 
     # Build the graph in BVGraph format (output: .{graph,offsets,properties})
     java_cmd it.unimi.dsi.big.webgraph.ScatteredArcsASCIIGraph          \
         --function $compr_graph_path.mph --temp-dir $tmp_dir            \
         --zipped $compr_graph_path-bv < $graph_path.edges.csv.gz        &&
     # Build the offset big-list file to load the graph faster (output: .obl)
     java_cmd it.unimi.dsi.big.webgraph.BVGraph                          \
         --list $compr_graph_path-bv                                     &&
 
     # Find a better permutation using a BFS traversal order (output: .order)
     java_cmd it.unimi.dsi.law.big.graph.BFS                             \
         $compr_graph_path-bv $compr_graph_path.order                    &&
 
     # Permute the graph accordingly
     java_cmd it.unimi.dsi.big.webgraph.Transform mapOffline             \
         $compr_graph_path-bv $compr_graph_path                          \
         $compr_graph_path.order $batch_size $tmp_dir                    &&
     java_cmd it.unimi.dsi.big.webgraph.BVGraph                          \
         --list $compr_graph_path                                        &&
 
     # Compute graph statistics (output: .{indegree,outdegree,stats})
     java_cmd it.unimi.dsi.big.webgraph.Stats $compr_graph_path          &&
 
     # Create transposed graph (to allow backward traversal)
     java_cmd it.unimi.dsi.big.webgraph.Transform transposeOffline       \
         $compr_graph_path $compr_graph_path-transposed                  \
         $batch_size $tmp_dir                                            &&
     java_cmd it.unimi.dsi.big.webgraph.BVGraph                          \
         --list $compr_graph_path-transposed
 } > $stdout_file 2> $stderr_file
 
 if [[ $? -eq 0 ]]; then
     echo "Graph compression done."
 else
     echo "Graph compression failed: see $stderr_file for more info."
     exit 1
 fi