How to keep elastic search running on linux server

Question

I am accessing my server using ssh via Putty client but when my putty goes inactive or I close it elastic search stops. I want to keep it running all the time. How can I achieve this?

Answer 1

The issue you have is that elasticsearch is not being started as a daemon (server). Instead you starting it as you would a normal program. Therefore when you stop your SSH session, the program stops running.

In order to get elasticsearch to start when the server itself is rebooted, you need to add elasticsearch to the server startup.

You didn't say which operating system you are running on the server. Let's assume it's a Debian (eg Ubuntu) system), you must create a file that you can place in the directory /etc/init.d.

I have copied the file from my own server below. You may already have it. Look for the file /etc/init.d/elasticsearch

$ more /etc/init.d/elasticsearch 

Once you have the file you can run the command

sudo update-rc.d elasticsearch defaults 95 10

This will "install" elasticsearch as a service.

To start and stop the service, you can run the commands :

sudo  service elasticsearch start
sudo  service elasticsearch stop

The file is below if you don't have it already.

#!/bin/sh
#
# /etc/init.d/elasticsearch -- startup script for Elasticsearch
#
# Written by Miquel van Smoorenburg <[email protected]>.
# Modified for Debian GNU/Linux by Ian Murdock <[email protected]>.
# Modified for Tomcat by Stefan Gybas <[email protected]>.
# Modified for Tomcat6 by Thierry Carrez <[email protected]>.
# Additional improvements by Jason Brittain <[email protected]>.
# Modified by Nicolas Huray for Elasticsearch <[email protected]>.
#
### BEGIN INIT INFO
# Provides:          elasticsearch
# Required-Start:    $network $remote_fs $named
# Required-Stop:     $network $remote_fs $named
# Default-Start:     2 3 4 5
# Default-Stop:      0 1 6
# Short-Description: Starts elasticsearch
# Description:       Starts elasticsearch using start-stop-daemon
### END INIT INFO

PATH=/bin:/usr/bin:/sbin:/usr/sbin
NAME=elasticsearch
DESC="Elasticsearch Server"
DEFAULT=/etc/default/$NAME

if [ `id -u` -ne 0 ]; then
    echo "You need root privileges to run this script"
    exit 1
fi


. /lib/lsb/init-functions

if [ -r /etc/default/rcS ]; then
    . /etc/default/rcS
fi


# The following variables can be overwritten in $DEFAULT

# Run Elasticsearch as this user ID and group ID
ES_USER=elasticsearch
ES_GROUP=elasticsearch

# The first existing directory is used for JAVA_HOME (if JAVA_HOME is not defined in $DEFAULT)
JDK_DIRS="/usr/lib/jvm/java-8-oracle/ /usr/lib/jvm/j2sdk1.8-oracle/ /usr/lib/jvm/jdk-7-oracle-x64 /usr/lib/jvm/java-7-oracle /usr/lib/jvm/j2sdk1.7-oracle/ /usr/lib/jvm/jav
a-7-openjdk /usr/lib/jvm/java-7-openjdk-amd64/ /usr/lib/jvm/java-7-openjdk-armhf /usr/lib/jvm/java-7-openjdk-i386/ /usr/lib/jvm/default-java"

# Look for the right JVM to use
for jdir in $JDK_DIRS; do
    if [ -r "$jdir/bin/java" -a -z "${JAVA_HOME}" ]; then
        JAVA_HOME="$jdir"
    fi
done
export JAVA_HOME

# Directory where the Elasticsearch binary distribution resides
ES_HOME=/usr/share/$NAME

# Heap size defaults to 256m min, 1g max
# Set ES_HEAP_SIZE to 50% of available RAM, but no more than 31g
#ES_HEAP_SIZE=2g

# Heap new generation
#ES_HEAP_NEWSIZE=

# max direct memory
#ES_DIRECT_SIZE=

# Additional Java OPTS
#ES_JAVA_OPTS=

# Maximum number of open files
MAX_OPEN_FILES=65535

# Maximum amount of locked memory
#MAX_LOCKED_MEMORY=

# Elasticsearch log directory
LOG_DIR=/var/log/$NAME

# Elasticsearch data directory
DATA_DIR=/var/lib/$NAME

# Elasticsearch work directory
WORK_DIR=/tmp/$NAME

# Elasticsearch configuration directory
CONF_DIR=/etc/$NAME

# Elasticsearch configuration file (elasticsearch.yml)
CONF_FILE=$CONF_DIR/elasticsearch.yml

# Maximum number of VMA (Virtual Memory Areas) a process can own
MAX_MAP_COUNT=262144

# End of variables that can be overwritten in $DEFAULT

# overwrite settings from default file
if [ -f "$DEFAULT" ]; then
    . "$DEFAULT"
fi

# Define other required variables
PID_FILE=/var/run/$NAME.pid
DAEMON=$ES_HOME/bin/elasticsearch
DAEMON_OPTS="-d -p $PID_FILE --default.config=$CONF_FILE --default.path.home=$ES_HOME --default.path.logs=$LOG_DIR --default.path.data=$DATA_DIR --default.path.work=$WORK_
DIR --default.path.conf=$CONF_DIR"

export ES_HEAP_SIZE
export ES_HEAP_NEWSIZE
export ES_DIRECT_SIZE
export ES_JAVA_OPTS

# Check DAEMON exists
test -x $DAEMON || exit 0

checkJava() {
    if [ -x "$JAVA_HOME/bin/java" ]; then
        JAVA="$JAVA_HOME/bin/java"
    else
        JAVA=`which java`
    fi

    if [ ! -x "$JAVA" ]; then
        echo "Could not find any executable java binary. Please install java in your PATH or set JAVA_HOME"
        exit 1
    fi
}

case "$1" in
  start)
    checkJava

    if [ -n "$MAX_LOCKED_MEMORY" -a -z "$ES_HEAP_SIZE" ]; then
        log_failure_msg "MAX_LOCKED_MEMORY is set - ES_HEAP_SIZE must also be set"
        exit 1
    fi

    log_daemon_msg "Starting $DESC"

    pid=`pidofproc -p $PID_FILE elasticsearch`
    if [ -n "$pid" ] ; then
        log_begin_msg "Already running."
        log_end_msg 0
        exit 0
    fi

    # Prepare environment
    mkdir -p "$LOG_DIR" "$DATA_DIR" "$WORK_DIR" && chown "$ES_USER":"$ES_GROUP" "$LOG_DIR" "$DATA_DIR" "$WORK_DIR"
    touch "$PID_FILE" && chown "$ES_USER":"$ES_GROUP" "$PID_FILE"

    if [ -n "$MAX_OPEN_FILES" ]; then
        ulimit -n $MAX_OPEN_FILES
    fi

    if [ -n "$MAX_LOCKED_MEMORY" ]; then
        ulimit -l $MAX_LOCKED_MEMORY
    fi

    if [ -n "$MAX_MAP_COUNT" -a -f /proc/sys/vm/max_map_count ]; then
        sysctl -q -w vm.max_map_count=$MAX_MAP_COUNT
    fi

    # Start Daemon
    start-stop-daemon --start -b --user "$ES_USER" -c "$ES_USER" --pidfile "$PID_FILE" --exec $DAEMON -- $DAEMON_OPTS
    return=$?
    if [ $return -eq 0 ]
    then
        i=0
        timeout=10
        # Wait for the process to be properly started before exiting
        until { cat "$PID_FILE" | xargs kill -0; } >/dev/null 2>&1
        do
            sleep 1
            i=$(($i + 1))
            [ $i -gt $timeout ] && log_end_msg 1
        done
    else
        log_end_msg $return
    fi
    ;;      
  stop)
    log_daemon_msg "Stopping $DESC"

    if [ -f "$PID_FILE" ]; then 
        start-stop-daemon --stop --pidfile "$PID_FILE" \
            --user "$ES_USER" \
            --retry=TERM/20/KILL/5 >/dev/null
        if [ $? -eq 1 ]; then
            log_progress_msg "$DESC is not running but pid file exists, cleaning up"
        elif [ $? -eq 3 ]; then
            PID="`cat $PID_FILE`"
            log_failure_msg "Failed to stop $DESC (pid $PID)"
            exit 1
        fi
        rm -f "$PID_FILE"
    else
        log_progress_msg "(not running)"
    fi
    log_end_msg 0
    ;;
  status)
    status_of_proc -p $PID_FILE elasticsearch elasticsearch && exit 0 || exit $?
    ;;
  restart|force-reload)
    if [ -f "$PID_FILE" ]; then
        $0 stop
        sleep 1
    fi
    $0 start
    ;;
  *)
    log_success_msg "Usage: $0 {start|stop|restart|force-reload|status}"
    exit 1
    ;;
esac

exit 0

Answer 2

I needed to install ElasticSearch using debian package. Details here https://www.digitalocean.com/community/tutorials/how-to-install-and-configure-elasticsearch-on-ubuntu-14-04