Generate flame graphs of JVM, JAVA

java-flamegraph.sh

#!/bin/bash

# SJK tool need to run as the same user of the target process.
USER=
PID=
INTERVAL=10ms

PROGRAM_NAME=$(basename $0)

error() {
    local exitcode="$1"
    shift
    echo "$PROGRAM_NAME: $*" 1>&2
    [ "$exitcode" -ne 0 ] && exit "$exitcode"
}

while getopts "u:p:i:h" opt; do
    case "$opt" in
        u)
            USER=$OPTARG
            ;;
        p)
            PID=$OPTARG
            ;;
        i)
            INTERVAL=$OPTARG
            ;;
        h)
            cat <<EOF
Usage: $PROGRAM_NAME [OPTION...]

   -u USER   user id of the target Java process
   -p PID    pid of the target Java process

EOF
    esac
done
shift $((OPTIND - 1))


[ -z "$PID" ] && error 1 "missing PID, use -p PID"
[ -z "$USER" ] && error 1 "missing USER, use -u USER"

SJK_JAR=sjk-0.10-SNAPSHOT.jar
SJK="/tmp/$SJK_JAR"
SJK_SOURCE="https://github.com/cinsk/jvm-tools/blob/master/release/${SJK_JAR}?raw=true"

echo "Retrieving $SJK_SOURCE"
curl -s -o "$SJK" -L -k "$SJK_SOURCE"

# if [ -z "$PID" ]; then
#     if [ "$(pgrep -u cassandra java | wc -l)" -ne 1 ]; then
#         echo "more than one Java process owned by the user cassandra" 1>&2
#         exit 1
#     fi
#     PID="$(pgrep -u cassandra java)"
# fi

SJK_DUMP=/tmp/flamegraph-sjk-dump.$$.std
FLAME_OUTPUT=/tmp/flame-${PID}-$(hostname).svg

[ -f "$SJK_DUMP" ] && rm -f "$SJK_DUMP"

trap "rm -f $SJK_DUMP" EXIT

sudo -u "$USER" java -jar "$SJK" stcap -p $PID -i "$INTERVAL" -o "$SJK_DUMP" "$@"
java -jar "$SJK" ssa --flame -f "$SJK_DUMP" > "$FLAME_OUTPUT"
echo "flamegraph: $FLAME_OUTPUT"
rm -f "$SJK_DUMP"