jstack-profiler

#!/bin/bash
# Copyright (c) 2018, WSO2 Inc. (http://wso2.org) All Rights Reserved.
#
# WSO2 Inc. licenses this file to you under the Apache License,
# Version 2.0 (the "License"); you may not use this file except
# in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing,
# software distributed under the License is distributed on an
# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
# KIND, either express or implied.  See the License for the
# specific language governing permissions and limitations
# under the License.
#
# ----------------------------------------------------------------------------
# Profile Java Applications using jstack command
# ----------------------------------------------------------------------------

pid=$(pgrep -o java || echo "")
number_of_samples=30
sample_interval=2s
output_directory=""
save_ps_output=true

function help() {
    echo ""
    echo "Usage: "
    echo "jstack-profiler [-p <pid>] [-n <number_of_samples>] [-i <sample_interval[suffix]>] [-o <output_directory>] [-x] [-h]"
    echo ""
    echo "-p: The Java Process ID. Default: Oldest Java Application"
    echo "-n: Number of samples to take. Default: $number_of_samples"
    echo "-i: Sample interval. Default: $sample_interval. Floating point numbers are accepted"
    echo "    Suffix may be: "
    echo "    s - seconds (the default)"
    echo "    m - minutes"
    echo "    h - hours"
    echo "    d - days"
    echo "-o: Output directory to save results"
    echo "-x: Do not save 'ps' command output"
    echo "-h: Display this help"
    echo ""
}

while getopts "hp:n:i:o:" opts; do
    case $opts in
    h)
        help
        exit 0
        ;;
    p)
        pid=${OPTARG}
        ;;
    n)
        number_of_samples=${OPTARG}
        ;;
    i)
        sample_interval=${OPTARG}
        ;;
    o)
        output_directory=${OPTARG}
        ;;
    x)
        save_ps_output=false
        ;;
    \?)
        help
        exit 1
        ;;
    esac
done

if [[ -z $pid ]]; then
    echo "Please specify the Java Process ID"
    exit 1
fi

if ! kill -0 $pid >/dev/null 2>&1; then
    echo "Please make sure the process exists" >&2
    exit 1
fi

if [[ -z $output_directory ]]; then
    # Use temp directory
    output_directory=$(mktemp -d /tmp/jstack-profiler.XXXXXX)
elif [[ ! -d $output_directory ]]; then
    mkdir $output_directory
fi

echo "Profiling the process with PID: $pid. The jstack samples will be saved in $output_directory"
counter=0
while [[ $counter -lt $number_of_samples ]]; do
    prefix=$(date +%s%3N)
    ps_output_file=$output_directory/$prefix-ps.txt
    thread_dump_file=$output_directory/$prefix-thread-dump.txt
    if [[ $save_ps_output == true ]]; then
        # Make sure following command is the same 'ps' command used in 'top-threads' script
        if ! ps -p $pid -T -o "%cpu=,%mem=,state=,nice=,cputime=,lwp=,pid=" | sort -nr |
            sed -E -e 's/^[[:space:]]*//' -e 's/[[:space:]]+/,/g' >$ps_output_file; then
            echo "An error was encountered when getting the 'ps' report of process $pid."
            break
        fi
    fi
    # Get thread dump
    if ! jstack ${JSTACK_OPTS} $pid >$thread_dump_file; then
        echo "An error was encountered when getting a thread dump of process $pid."
        break
    fi
    let counter+=1
    let progress=$counter*100/$number_of_samples*100/100
    echo -ne "\rProgress: $progress%"
    if [[ $counter -lt $number_of_samples ]]; then
        sleep $sample_interval
    fi
done
# Clear progress line
echo -ne "\rCompleted.      \n"