diff --git a/.gitignore b/.gitignore
index fcff087..c090b7d 100644
--- a/.gitignore
+++ b/.gitignore
@@ -31,3 +31,7 @@ vignettes/*.pdf
 # Temporary files created by R markdown
 *.utf8.md
 *.knit.md
+.Rproj.user
+
+logs/*
+.R.user
diff --git a/config-parallel.R b/config-parallel.R
new file mode 100644
index 0000000..7ecd069
--- /dev/null
+++ b/config-parallel.R
@@ -0,0 +1,54 @@
+# ---- config-parallel ----
+
+PARALLEL.USED.METHOD               = "REMOTE" # LOCAL or REMOTE
+PARALLEL.DISABLE.MKL.THREADS       = TRUE
+
+PARALLEL.NO.JOBS.PER.CHUNK         = 30 # no. jobs per worker in step 6-2
+PARALLEL.NO.JOBS.MULTIPLIER        = 2  # no. jobs multiplier per job sequence
+                                        # to minimize worker time of waitiing for
+                                        # remaining workers in step 6-2
+
+# local
+PARALLEL.LOCAL.METHOD              = "PSOCK"
+
+PARALLEL.LOCAL.NODES               = parallel::detectCores(logical = FALSE)
+PARALLEL.LOCAL.CONNECTION.TIMEOUT  = 5
+PARALLEL.LOCAL.SLAVE.OUT.FILE      =
+    lazy(file.path(LOGGER.OUTPUT.DIR,
+                   paste0("worker-local-", worker.name, "-", worker.id, ".log")))
+
+# remote
+PARALLEL.REMOTE.METHOD                    = "PSOCK"
+
+PARALLEL.REMOTE.MASTER.IP                 = "192.168.0.1" # ip accessible from slaves
+PARALLEL.REMOTE.MASTER.PORT               = 11000
+PARALLEL.REMOTE.MASTER.CONNECTION.TIMEOUT = 10
+PARALLEL.REMOTE.MASTER.SSH.PROGRAM        = "ssh" # ssh, ssh.exe, etc.
+PARALLEL.REMOTE.MASTER.SSH.PRIV.KEY       = file.path("ssh", "rsa-priv.key")
+PARALLEL.REMOTE.MASTER.SSH.NULL.DEV       = "/dev/null"
+PARALLEL.REMOTE.MASTER.SSH.STRICT.HOST.KEY.CHECKING = "no"
+PARALLEL.REMOTE.MASTER.SSH.SERVER.ALIVE.INTERVAL    = 30
+PARALLEL.REMOTE.MASTER.SHELL.CMD          =
+paste0(
+  PARALLEL.REMOTE.MASTER.SSH.PROGRAM,
+  " -q",
+  " -o ConnectTimeout=",        PARALLEL.REMOTE.MASTER.CONNECTION.TIMEOUT,
+  " -o UserKnownHostsFile=",    PARALLEL.REMOTE.MASTER.SSH.NULL.DEV,
+  " -o StrictHostKeyChecking=", PARALLEL.REMOTE.MASTER.SSH.STRICT.HOST.KEY.CHECKING,
+  " -o ServerAliveInterval=",   PARALLEL.REMOTE.MASTER.SSH.SERVER.ALIVE.INTERVAL,
+  " -i ",                       PARALLEL.REMOTE.MASTER.SSH.PRIV.KEY)
+
+PARALLEL.REMOTE.MASTER.SLAVES.FILE.PATH = "remote-connection-list.txt"
+
+PARALLEL.REMOTE.SLAVE.OUT.FILE     = lazy(paste0("worker-remote-", worker.name,
+                                                 "-", worker.id, ".log"))
+PARALLEL.REMOTE.SLAVE.SSH.USER     = "root"
+PARALLEL.REMOTE.SLAVE.RSCRIPT.PATH = "/usr/bin/Rscript"
+PARALLEL.REMOTE.SLAVE.HOMOGENEOUS  = TRUE
+PARALLEL.REMOTE.SLAVE.METHODS      = TRUE
+PARALLEL.REMOTE.SLAVE.USEXDR       = TRUE
+
+# perform additional custom config
+
+if (file.exists("config-parallel.R.user"))
+    source("config-parallel.R.user")
diff --git a/config.R b/config.R
new file mode 100644
index 0000000..b0d5920
--- /dev/null
+++ b/config.R
@@ -0,0 +1,31 @@
+# ---- config ----
+
+# randomization and output files
+
+SEED                   = 1337
+OVERWRITE.OUTPUT.FILES = TRUE # overwrite created datasets and classifiers
+
+# extra user configuration and init
+
+USER.CONFIG.FILE      = "config.R.user"
+USER.INIT.FILE        = "init.R.user"
+
+# checkpoint library
+
+CHECKPOINT.QUICK.LOAD    = FALSE # if TRUE then skip testing https and checking url
+CHECKPOINT.MRAN.URL      = "http://mran.microsoft.com/"
+CHECKPOINT.SNAPSHOT.DATE = "2016-07-01"
+
+# logging system
+
+LOGGER.OUTPUT.DIR               = "logs"
+LOGGER.OUTPUT.TEST.FILE         = "output-test.log"
+LOGGER.LEVEL                    = 6 # futile.logger::INFO
+LOGGER.OVERWRITE.EXISTING.FILES = TRUE
+
+# load custom config
+
+if (file.exists(USER.CONFIG.FILE))
+{
+    source(USER.CONFIG.FILE)
+}
diff --git a/init-parallel.R b/init-parallel.R
new file mode 100644
index 0000000..cb1300c
--- /dev/null
+++ b/init-parallel.R
@@ -0,0 +1,115 @@
+# ---- init-parallel ----
+
+# load setup variables
+
+source("config-parallel.R")
+source("utils-parallel.R")
+
+# create cluster
+
+cl = if (PARALLEL.USED.METHOD == "LOCAL")
+{
+    if (PARALLEL.LOCAL.METHOD == "PSOCK")
+    {
+        flog.info("Creating local PSOCK cluster")
+        make.psock.cluster(
+            names              = PARALLEL.LOCAL.NODES,
+            connection.timeout = PARALLEL.LOCAL.CONNECTION.TIMEOUT,
+            outfile            = PARALLEL.LOCAL.SLAVE.OUT.FILE)
+    } else if (PARALLEL.LOCAL.METHOD == "FORK")
+    {
+        flog.info("Creating local FORK cluster")
+        makeForkCluster(PARALLEL.LOCAL.NODES)
+    } else {
+        stop.script(paste("Unknown local parallel cluster method:",
+                          PARALLEL.USED.METHOD))
+    }
+} else if (PARALLEL.USED.METHOD == "REMOTE")
+{
+    if (PARALLEL.REMOTE.METHOD == "PSOCK")
+    {
+        flog.info("Creating remote PSOCK cluster")
+
+        if (!file.exists(PARALLEL.REMOTE.MASTER.SLAVES.FILE.PATH))
+        {
+            stop.script(paste("Unable to read list of remote hosts from",
+                              PARALLEL.REMOTE.MASTER.SLAVES.FILE.PATH))
+        }
+
+        slaves.list = readLines(PARALLEL.REMOTE.MASTER.SLAVES.FILE.PATH)
+
+        make.psock.cluster(
+            names              = slaves.list,
+            connection.timeout = PARALLEL.REMOTE.MASTER.CONNECTION.TIMEOUT,
+            master             = PARALLEL.REMOTE.MASTER.IP,
+            port               = PARALLEL.REMOTE.MASTER.PORT,
+            rshcmd             = PARALLEL.REMOTE.MASTER.SHELL.CMD,
+            outfile            = PARALLEL.REMOTE.SLAVE.OUT.FILE,
+            user               = PARALLEL.REMOTE.SLAVE.SSH.USER,
+            rscript            = PARALLEL.REMOTE.SLAVE.RSCRIPT.PATH,
+            homogeneous        = PARALLEL.REMOTE.SLAVE.HOMOGENEOUS,
+            methods            = PARALLEL.REMOTE.SLAVE.METHODS,
+            useXDR             = PARALLEL.REMOTE.SLAVE.USEXDR)
+    }
+    else {
+        stop.script(paste("Unknown remote parallel cluster method:",
+                          PARALLEL.REMOTE.METHOD))
+    }
+} else {
+    stop.script(paste("Unknown used parallel method:", PARALLEL.USED.METHOD))
+}
+
+
+flog.info("Exporting checkpoint constants")
+clusterExport(cl, c("CHECKPOINT.QUICK.LOAD", "CHECKPOINT.MRAN.URL",
+                    "CHECKPOINT.SNAPSHOT.DATE", "LOGGER.LEVEL"))
+
+clusterEvalQ(cl, {
+    library(checkpoint)
+
+    if (CHECKPOINT.QUICK.LOAD) # approx. x10 faster checkpoint library loading
+    {
+        # assume https
+        options(checkpoint.mranUrl = CHECKPOINT.MRAN.URL)
+        # disable url checking
+        assignInNamespace("is.404", function(mran, warn = TRUE) { FALSE },
+                          "checkpoint")
+    }
+
+    checkpoint(CHECKPOINT.SNAPSHOT.DATE, verbose = TRUE, scanForPackages = TRUE)
+
+    library(futile.logger)
+
+    flog.threshold(LOGGER.LEVEL)
+
+    flog.info("Logging configured")
+})
+
+if (PARALLEL.DISABLE.MKL.THREADS)
+{
+    clusterEvalQ(cl, {
+        tryCatch({setMKLthreads(1);
+                  flog.info("Set MKL threads to 1 on slave")},
+                 error = function(e) e)
+    })
+}
+
+flog.info("Setting cluster RNG kind")
+clusterEvalQ(cl, {
+    RNGkind("L'Ecuyer-CMRG")
+})
+
+flog.info("Registering cluster")
+registerDoParallel(cl)
+
+foreach::foreach(i = 1:foreach::getDoParWorkers()) %dopar%
+{
+    flog.info("Foreach startup test")
+}
+
+flog.info(paste(rep("*", 25), collapse = ""))
+
+# perform additional custom init
+
+if (file.exists("init-parallel.R.user"))
+    source("init-parallel.R.user")
diff --git a/init.R b/init.R
new file mode 100644
index 0000000..15411db
--- /dev/null
+++ b/init.R
@@ -0,0 +1,79 @@
+# ---- init ----
+
+# stop cluster if it is already registered
+
+if ("cl" %in% ls() && !is.null(foreach::getDoParName()))
+{
+    if (foreach::getDoParName() != "doSEQ")
+    {
+        flog.info("Stopping already registered cluster")
+        stop.cluster()
+    }
+}
+
+# clear envirionment
+
+rm(list = ls())
+
+# load setup variables
+
+source("config.R")
+
+# load library management system
+
+suppressPackageStartupMessages(
+    library(checkpoint)
+)
+
+if (CHECKPOINT.QUICK.LOAD) # approx. x10 faster checkpoint library loading
+{
+    # assume https
+    options(checkpoint.mranUrl = CHECKPOINT.MRAN.URL)
+    # disable url checking
+    assignInNamespace("is.404", function(mran, warn = TRUE) { FALSE },
+                      "checkpoint")
+}
+
+checkpoint(CHECKPOINT.SNAPSHOT.DATE, verbose = TRUE, scanForPackages = TRUE)
+
+# load logging system
+
+suppressPackageStartupMessages(
+    library(futile.logger)
+)
+
+invisible(flog.threshold(LOGGER.LEVEL))
+
+if (!dir.exists(LOGGER.OUTPUT.DIR))
+{
+    dir.create(LOGGER.OUTPUT.DIR, recursive = TRUE)
+}
+
+# load libraries
+
+suppressPackageStartupMessages({
+    library(plyr)
+    library(dplyr)
+    library(ttutils)
+    library(lazyeval)
+    library(R.utils)
+    library(RCurl)
+    # caret - core
+    library(caret)
+    library(e1071)
+    # caret - classifiers
+    library(kernlab) # SVM
+    # parallel computation
+    library(doParallel)
+})
+
+# load helper functions
+
+source("utils.R")
+
+# perform additional custom init
+
+if (file.exists(USER.INIT.FILE))
+{
+    source(USER.INIT.FILE)
+}
diff --git a/r-distributed-computing.Rproj b/r-distributed-computing.Rproj
new file mode 100644
index 0000000..9241cc8
--- /dev/null
+++ b/r-distributed-computing.Rproj
@@ -0,0 +1,16 @@
+Version: 1.0
+
+RestoreWorkspace: Default
+SaveWorkspace: Default
+AlwaysSaveHistory: Default
+
+EnableCodeIndexing: Yes
+UseSpacesForTab: Yes
+NumSpacesForTab: 4
+Encoding: UTF-8
+
+RnwWeave: Sweave
+LaTeX: pdfLaTeX
+
+AutoAppendNewline: Yes
+StripTrailingWhitespace: Yes
diff --git a/remote-commands.sh b/remote-commands.sh
new file mode 100644
index 0000000..878e203
--- /dev/null
+++ b/remote-commands.sh
@@ -0,0 +1,520 @@
+#!/bin/bash
+
+# working with WMI Rescue - small Linux image based on 
+# Debian distribution; see http://rescue.wmi.amu.edu.pl
+
+# config
+
+MRO_VERSION="3.3.1"
+SSH_OPTIONS="-o ConnectTimeout=5 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -q"
+SSH_USER="root"
+SSHPASS_PWD="wmi"
+SSH_KEYS_DIR="ssh"
+SSH_KEY_PRIV="rsa-priv.key"
+SSH_KEY_PUB="rsa-pub.key"
+MRO_INSTALL_URL="https://mran.microsoft.com/install"
+HOSTS_FILE="remote-hosts.txt"
+CONNECTION_LIST_FILE="remote-connection-list.txt"
+HOSTS_SCANNED_FILE="remote-hosts-scanned.txt"
+DEBIAN_PACKAGES_TO_INSTALL="build-essential gfortran ed htop libxml2-dev ca-certificates curl libcurl4-openssl-dev gdebi-core sshpass default-jre default-jdk libpcre3-dev zlib1g-dev liblzma-dev libbz2-dev libicu-dev"
+REMOTE_DETECT_LOGICAL_CPUS="FALSE"
+MIN_HOSTS=100
+
+SHELL_SCRIPT=$(basename $0)
+LOG_STEPS="logs/${SHELL_SCRIPT%.*}".log
+HOSTS_ARRAY=()
+
+# messaging
+
+report_error()
+{
+    echo $1 > /tmp/command_error.$$
+}
+
+[[ -w /tmp ]] && report_error 0
+
+# https://stackoverflow.com/a/5196220
+# modified for Debian
+
+# Use step(), try(), and next() to perform a series of commands and print
+# [  OK  ] or [FAILED] at the end. The step as a whole fails if any individual
+# command fails.
+#
+# Example:
+#     step "Remounting / and /boot as read-write:"
+#     try mount -o remount,rw /
+#     try mount -o remount,rw /boot
+#     next
+step()
+{
+    echo -n "* $@   "
+
+    STEP_OK=0
+    [[ -w /tmp ]] && echo $STEP_OK > /tmp/step.$$
+}
+
+try()
+{
+    # skip if previous command in step failed
+    [[ -f /tmp/step.$$ ]] && { PREV_STEP=$(< /tmp/step.$$); }
+    [[ $PREV_STEP -ne 0 ]] && return 1
+
+    # Check for `-b' argument to run command in the background.
+    local BG=
+
+    [[ $1 == -b ]] && { BG=1; shift; }
+    [[ $1 == -- ]] && {       shift; }
+
+    # Run the command.
+    if [[ -z $BG ]]; then
+        "$@"
+    else
+        "$@" &
+    fi
+
+    # Check if command failed and update $STEP_OK if so.
+    local EXIT_CODE=$?
+
+    if [[ $EXIT_CODE -ne 0 ]]; then
+        STEP_OK=$EXIT_CODE
+        [[ -w /tmp ]] && echo $STEP_OK > /tmp/step.$$
+
+        if [[ -n $LOG_STEPS ]]; then
+            local FILE=$(readlink -m "${BASH_SOURCE[1]}")
+            local LINE=${BASH_LINENO[0]}
+            
+            mkdir -p $( dirname $LOG_STEPS )
+
+            echo "$FILE: line $LINE: Command \`$*' failed with exit code $EXIT_CODE." >> "$LOG_STEPS"
+        fi
+    fi
+
+    return $EXIT_CODE
+}
+
+test -t 1 && CONSOLE_STDOUT=1 || CONSOLE_STDOUT=0
+[[ $TERM != "dumb" ]] && [[ $CONSOLE_STDOUT -eq 1 ]] && CONSOLE_COLORS=1 || CONSOLE_COLORS=0
+
+[ $CONSOLE_COLORS -eq 1 ] && CONSOLE_RED=$(tput setaf 1)
+[ $CONSOLE_COLORS -eq 1 ] && CONSOLE_GREEN=$(tput setaf 2)
+[ $CONSOLE_COLORS -eq 1 ] && CONSOLE_YELLOW=$(tput setaf 3)
+[ $CONSOLE_COLORS -eq 1 ] && CONSOLE_NORMAL=$(tput sgr0)
+[ $CONSOLE_COLORS -eq 1 ] && CONSOLE_RESULT_POS=$[$(tput cols)-10] || CONSOLE_RESULT_POS=0
+
+next()
+{
+    # https://stackoverflow.com/a/5506264
+    [ $CONSOLE_COLORS -eq 1 ] && tput hpa ${CONSOLE_RESULT_POS}
+
+    [[ -f /tmp/step.$$ ]] && { STEP_OK=$(< /tmp/step.$$); rm -f /tmp/step.$$; }
+    [[ $STEP_OK -eq 0 ]]  && printf '%s%s' "$CONSOLE_GREEN" "[ OK ]" "$CONSOLE_NORMAL" || printf '%s%s' "$CONSOLE_RED" "[FAIL]" "$CONSOLE_NORMAL"
+    echo
+    
+    [[ $STEP_OK -ne 0 ]] && report_error 1
+
+    return $STEP_OK
+}
+
+info()
+{
+    echo -n "* $@   "
+    [ $CONSOLE_COLORS -eq 1 ] && tput hpa ${CONSOLE_RESULT_POS}
+    printf '%s' "[INFO]"
+    echo
+}
+
+fail()
+{
+    echo -n "* $@   "
+    [ $CONSOLE_COLORS -eq 1 ] && tput hpa ${CONSOLE_RESULT_POS}
+    printf '%s%s' "$CONSOLE_RED" "[FAIL]" "$CONSOLE_NORMAL"
+    echo
+}
+
+success()
+{
+    echo -n "* $@   "
+    [ $CONSOLE_COLORS -eq 1 ] && tput hpa ${CONSOLE_RESULT_POS}
+    printf '%s%s' "$CONSOLE_GREEN" "[ OK ]" "$CONSOLE_NORMAL"
+    echo
+}
+
+warn()
+{
+    echo -n "* $@   "
+    [ $CONSOLE_COLORS -eq 1 ] && tput hpa ${CONSOLE_RESULT_POS}
+    printf '%s%s' "$CONSOLE_YELLOW" "[WARN]" "$CONSOLE_NORMAL"
+    echo
+}
+
+# functions
+
+generate_ssh_keys()
+{
+    step "Generating SSH keys"
+    try mkdir -p ssh
+    try ssh-keygen -q -t rsa -b 4096 -f ${SSH_KEYS_DIR}/${SSH_KEY_PRIV} -P "" -C "rscript@remote"
+    try mv ${SSH_KEYS_DIR}/${SSH_KEY_PRIV}.pub ${SSH_KEYS_DIR}/${SSH_KEY_PUB}
+    next
+    check_if_command_error
+}
+
+install_env()
+{
+    step "Installing environment"
+    echo
+    try apt-get update
+    local DEBIAN_FRONTEND=noninteractive
+    try apt-get -y -o Dpkg::Options::="--force-confdef" -o Dpkg::Options::="--force-confnew" upgrade
+    try apt-get -y -o Dpkg::Options::="--force-confdef" -o Dpkg::Options::="--force-confnew" install ${DEBIAN_PACKAGES_TO_INSTALL}
+    try apt-get clean
+    next
+    check_if_command_error
+}
+
+install_mro()
+{
+    step "Installing Microsoft R Open"
+    echo
+    
+    Rscript -e "invisible(TRUE)" &> /dev/null
+    
+    if [[ $? -ne 0 ]]; then
+        try wget ${MRO_INSTALL_URL}/mro/${MRO_VERSION}/microsoft-r-open-${MRO_VERSION}.tar.gz
+        try tar -xvf microsoft-r-open-${MRO_VERSION}.tar.gz
+        try gdebi -n microsoft-r-open/deb/microsoft-r-open-mro-${MRO_VERSION:0:3}.deb
+        try gdebi -n microsoft-r-open/deb/microsoft-r-open-foreachiterators-${MRO_VERSION:0:3}.deb
+        try gdebi -n microsoft-r-open/deb/microsoft-r-open-mkl-${MRO_VERSION:0:3}.deb
+        try R CMD javareconf
+        rm -rf microsoft-r-open*
+    else
+        echo "Microsoft R Open already installed"
+    fi
+    
+    try Rscript -e "install.packages('knitr')"
+    
+    
+    try apt-get clean
+    next
+    check_if_command_error
+}
+
+install_r_libraries()
+{
+    step "Installing R libraries"
+    echo
+    try mkdir -p ~/.checkpoint
+    try Rscript init.R # run checkpoint
+    next
+    check_if_command_error
+}
+
+dump_project_r_files()
+{
+    step "Making project R files dump"
+    try tar -czf project-r-files.tar.gz *.R*
+    next
+    check_if_command_error
+}
+
+dump_r_libraries()
+{
+    step "Making R libraries dump"
+    wd=`pwd`
+    cd ~/
+    try tar -czf $wd/checkpoint.tar.gz .checkpoint/*
+    cd $wd
+    next
+    check_if_command_error
+}
+
+hosts_push_ssh_key()
+{
+    info "Pushing SSH keys to hosts"
+    for host in "${HOSTS_ARRAY[@]}"; do
+        step "-- ${host}"
+        try sshpass -p ${SSHPASS_PWD} ssh ${SSH_OPTIONS} ${SSH_USER}@${host} 'mkdir -p ~/.ssh'
+        try sshpass -p ${SSHPASS_PWD} scp ${SSH_OPTIONS} ${SSH_KEYS_DIR}/${SSH_KEY_PUB} ${SSH_USER}@${host}:~/.ssh
+        try sshpass -p ${SSHPASS_PWD} ssh ${SSH_OPTIONS} ${SSH_USER}@${host} "cat ~/.ssh/${SSH_KEY_PUB} >> ~/.ssh/authorized_keys"
+        try sshpass -p ${SSHPASS_PWD} ssh ${SSH_OPTIONS} ${SSH_USER}@${host} "sed -i -e 's/#PasswordAuthentication yes/PasswordAuthentication no/ig' /etc/ssh/sshd_config; service ssh restart"
+        next
+    done
+    check_if_command_error
+}
+
+hosts_scan_available()
+{
+    HOSTS_SCANNED_ARRAY=()
+    
+    info "Scanning available hosts"
+    for host in "${HOSTS_ARRAY[@]}"; do
+        ssh -o ConnectTimeout=2 -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no -o PreferredAuthentications=publickey -q -i ${SSH_KEYS_DIR}/${SSH_KEY_PRIV} ${SSH_USER}@${host} "true"
+        EXIT_CODE=$?
+        if [[ $EXIT_CODE -ne 0 ]]; then
+            fail "-- ${host}"
+        else
+            success "-- ${host}"
+            HOSTS_SCANNED_ARRAY+=("$host")
+        fi
+    done
+    
+    HOSTS_ARRAY=("${HOSTS_SCANNED_ARRAY[@]}")
+    
+    if [[ ${#HOSTS_ARRAY[@]} -eq 0 ]]; then
+        fail "No available hosts"
+        exit 1
+    else 
+        info "Available ${#HOSTS_ARRAY[@]} hosts"
+    fi
+    
+    if [[ ${#HOSTS_ARRAY[@]} -lt $MIN_HOSTS ]]; then
+        fail "Too few hosts: ${#HOSTS_ARRAY[@]} ; min.: $MIN_HOSTS"
+        exit 1
+    fi
+    
+    if [ -f ${HOSTS_SCANNED_FILE} ] ; then rm ${HOSTS_SCANNED_FILE}; fi
+    
+    for host in "${HOSTS_ARRAY[@]}"; do
+        echo ${host} >> ${HOSTS_SCANNED_FILE}
+    done
+}
+
+hosts_push_r_libraries_dump()
+{
+    info "Pushing R libraries dump to hosts"
+    for host in "${HOSTS_ARRAY[@]}"; do
+        step "-- ${host}"
+        try scp ${SSH_OPTIONS} -i ${SSH_KEYS_DIR}/${SSH_KEY_PRIV} checkpoint.tar.gz ${SSH_USER}@${host}:~/
+        try ssh ${SSH_OPTIONS} -i ${SSH_KEYS_DIR}/${SSH_KEY_PRIV} ${SSH_USER}@${host} "tar -xzf checkpoint.tar.gz -C ~/; rm checkpoint.tar.gz"
+        next
+    done
+    check_if_command_error
+}
+
+hosts_push_project_r_files()
+{
+    info "Pushing project R files to hosts"
+    for host in "${HOSTS_ARRAY[@]}"; do
+        step "-- ${host}"
+        try scp ${SSH_OPTIONS} -i ${SSH_KEYS_DIR}/${SSH_KEY_PRIV} project-r-files.tar.gz ${SSH_USER}@${host}:~/
+        try ssh ${SSH_OPTIONS} -i ${SSH_KEYS_DIR}/${SSH_KEY_PRIV} ${SSH_USER}@${host} "tar -xzf project-r-files.tar.gz -C ~/; rm project-r-files.tar.gz"
+        next
+    done
+    check_if_command_error
+}
+
+hosts_push_shell_script()
+{
+    info "Pushing shell script to hosts"
+    for host in "${HOSTS_ARRAY[@]}"; do
+        step "-- ${host}"
+        try scp ${SSH_OPTIONS} -i ${SSH_KEYS_DIR}/${SSH_KEY_PRIV} ${SHELL_SCRIPT} ${SSH_USER}@${host}:~/
+        next
+    done
+    check_if_command_error
+}
+
+hosts_install()
+{
+    case "$1" in
+        "env")          info "Installing environment on hosts" ;;
+        "mro")          info "Installing Microsoft R Open on hosts" ;;
+        "r_libraries")  info "Installing R libraries on hosts" ;;
+        *)              fail "Unknown remote install command"; report_error 1; check_if_command_error
+    esac
+
+    for host in "${HOSTS_ARRAY[@]}"; do
+        info "-- Invoking ${host}"
+        
+        {   ssh ${SSH_OPTIONS} -i ${SSH_KEYS_DIR}/${SSH_KEY_PRIV} ${SSH_USER}@${host} "bash ${SHELL_SCRIPT} install_$1 &> install_$1.log" ;
+            endcode=$?
+            if [ $endcode -eq 0 ] ; then
+                success "-- ${host} finished"
+            else
+                fail "-- ${host} finished"
+                report_error 1
+            fi
+        } &
+
+    done
+   
+    last_workers=-1
+    while true; do
+        current_workers=$(jobs -rp | wc -l)
+        if [ $current_workers -eq 0 ] ; then break; fi
+        if (( $current_workers % 5 == 0)) &&  [ "$current_workers" -ne "$last_workers" ] ; then
+            info "- Waiting for $current_workers hosts"
+            last_workers=$current_workers
+        fi
+        sleep 1
+    done
+    
+    check_if_command_error
+}
+
+hosts_install_env()         { hosts_install env; }
+hosts_install_mro()         { hosts_install mro; }
+hosts_install_r_libraries() { hosts_install r_libraries; }
+
+hosts_power_off()
+{
+    info "Power off on hosts"
+    for host in "${HOSTS_ARRAY[@]}"; do
+        step "-- ${host}"
+        try ssh ${SSH_OPTIONS} -i ${SSH_KEYS_DIR}/${SSH_KEY_PRIV} ${SSH_USER}@${host} "poweroff"
+        next
+    done
+    check_if_command_error
+}
+
+make_remote_connection_list()
+{
+    info "Making remote connection list:"
+    if [ -f ${CONNECTION_LIST_FILE} ] ; then rm ${CONNECTION_LIST_FILE}; fi
+    case "$1" in
+        "single")
+            step "one connection per host"
+            for host in "${HOSTS_ARRAY[@]}"; do
+                try echo ${host} >> ${CONNECTION_LIST_FILE}
+            done
+            next
+            ;;
+        "nproc")
+            info "'number of cores' per host" 
+            for host in "${HOSTS_ARRAY[@]}"; do
+                step "-- ${host}"
+                cornum=`try ssh ${SSH_OPTIONS} -i ${SSH_KEYS_DIR}/${SSH_KEY_PRIV} ${SSH_USER}@${host} '/usr/bin/Rscript -e "cat(parallel::detectCores(logical = ${REMOTE_DETECT_LOGICAL_CPUS}))"'`
+                
+                regex='^[0-9]+$'
+                if ! [[ $cornum =~ $regex ]] ; then
+                    try false
+                else
+                    for ((i=1; i<=$cornum; i++)); do try echo ${host} >> ${CONNECTION_LIST_FILE}; done
+                    echo -n "($cornum cores)   "
+                fi
+                next
+            done
+            ;;
+        *) 
+            fail "unknown type"
+            report_error 1
+    esac
+    check_if_command_error
+}
+
+make_remote_connection_list_single() { make_remote_connection_list single; }
+make_remote_connection_list_nproc()  { make_remote_connection_list nproc; }
+
+hosts_check_install_log()
+{    
+    info "Checking install log on hosts"
+    for host in "${HOSTS_ARRAY[@]}"; do
+        step "-- ${host}"
+        echo
+        try ssh ${SSH_OPTIONS/-q/} -o LogLevel=error -i ${SSH_KEYS_DIR}/${SSH_KEY_PRIV} ${SSH_USER}@${host} "cat install_$1.log"
+        next
+    done
+    check_if_command_error
+}
+
+hosts_check_install_log_env()         { hosts_check_install_log env; }
+hosts_check_install_log_mro()         { hosts_check_install_log mro; }
+hosts_check_install_log_r_libraries() { hosts_check_install_log r_libraries; }
+
+hosts_check_worker_log()
+{
+    info "Checking worker log on hosts"
+    for host in "${HOSTS_ARRAY[@]}"; do
+        step "-- ${host}"
+        echo
+        try ssh ${SSH_OPTIONS/-q/} -o LogLevel=error -i ${SSH_KEYS_DIR}/${SSH_KEY_PRIV} ${SSH_USER}@${host} "for f in worker-remote-*.log; do echo \$f; cat -n \$f; done"
+        next
+    done
+    check_if_command_error
+}
+
+hosts_clean_worker_log()
+{
+    info "Cleaning workers logs"
+    for host in "${HOSTS_ARRAY[@]}"; do
+        step "-- ${host}"
+        try ssh ${SSH_OPTIONS} -i ${SSH_KEYS_DIR}/${SSH_KEY_PRIV} ${SSH_USER}@${host} "rm -f worker-remote-*.log"
+        next
+    done
+    check_if_command_error
+}
+
+check_if_command_error()
+{
+    errcode=$(< /tmp/command_error.$$)
+    [[ $errcode -ne 0 ]] && { warn "Stopping script execution"; rm -f /tmp/command_error.$$; exit $errcode; }
+}
+
+my_configure_hosts()
+{
+    #generate_ssh_keys
+    #hosts_push_ssh_key
+    hosts_scan_available
+    hosts_push_shell_script
+    dump_project_r_files
+    hosts_push_project_r_files
+    hosts_install_env
+    hosts_install_mro
+    #hosts_install_r_libraries
+        hosts_push_r_libraries_dump
+    make_remote_connection_list_nproc
+        #make_remote_connection_list_single
+}
+
+configure_hosts()
+{
+    generate_ssh_keys
+    hosts_push_ssh_key
+    hosts_push_shell_script
+    dump_project_r_files
+    hosts_push_project_r_files
+    hosts_install_env
+    hosts_install_mro
+    hosts_install_r_libraries
+        #hosts_push_r_libraries_dump
+    make_remote_connection_list_nproc
+        #make_remote_connection_list_single
+}
+
+# read hosts from file or stdin
+
+if [ -t 0 ]; then
+    if [ ! -f "$HOSTS_FILE" ]
+    then
+        info "No hosts file, working with localhost"
+        HOSTS_ARRAY+=("127.0.0.1")
+    else
+        readarray -t HOSTS_ARRAY < $HOSTS_FILE
+    fi
+else
+    while read -r host ; do
+        HOSTS_ARRAY+=("$host")
+    done
+fi
+
+info "Working with ${#HOSTS_ARRAY[@]} hosts"
+
+# read arguments as commands
+
+for i in "$@"
+do
+    case "$i" in
+        "hosts_install"|"hosts_check_install_log"|"make_remote_connection_list"|"info"|"fail"|"success"|"warn"|"next"|"try"|"step") ;;
+        *) 
+            if [ "$(type -t $i)" = "function" ]; then 
+                $i
+            else
+                fail "Command $i not found"
+                report_error 127
+            fi
+    esac
+    
+    check_if_command_error
+done
+
+rm -f /tmp/command_error.$$
diff --git a/test.R b/test.R
new file mode 100644
index 0000000..ad460e8
--- /dev/null
+++ b/test.R
@@ -0,0 +1,41 @@
+# ---- init ----
+
+source("init.R")
+
+setup.logger(file.path(LOGGER.OUTPUT.DIR, LOGGER.OUTPUT.TEST.FILE),
+             LOGGER.OVERWRITE.EXISTING.FILES)
+
+source("init-parallel.R")
+
+# ---- foreach-test ----
+
+flog.info("Test foreach")
+
+fdata = foreach::foreach(i = 1:foreach::getDoParWorkers(),
+                 .combine = c) %dopar%
+{
+    Sys.sleep(1)
+    return(i)
+}
+
+print(fdata)
+
+# ---- caret-test ----
+
+flog.info("Test caret")
+
+tr.control = caret::trainControl(method        = "repeatedcv",
+                                 number        = 10,
+                                 repeats       = 10,
+                                 allowParallel = TRUE)
+
+model = caret::train(form      = mpg ~ .,
+                     data      = mtcars,
+                     method    = "svmLinear",
+                     trControl = tr.control)
+
+print(model)
+
+# ---- shutdown ----
+
+stop.cluster()
diff --git a/utils-parallel.R b/utils-parallel.R
new file mode 100644
index 0000000..d5abc06
--- /dev/null
+++ b/utils-parallel.R
@@ -0,0 +1,88 @@
+make.psock.cluster = function(names, connection.timeout, ...)
+{
+    if (is.numeric(names))
+    {
+        names = as.integer(names[1])
+        if (is.na(names) || names < 1)
+        {
+            stop.script("Numeric 'names' must be >= 1")
+        }
+        names = rep("localhost", names)
+    }
+
+    parallel:::.check_ncores(length(names))
+    options = parallel:::addClusterOptions(parallel:::defaultClusterOptions,
+                                            list(...))
+    cl = vector("list", length(names))
+
+    for (i in seq_along(cl))
+    {
+
+        flog.info(paste0("[", i, "/", length(cl), "] Connecting to ",
+                         names[[i]], " ... "))
+
+        options.copy     = parallel:::addClusterOptions(options, NULL)
+        options.out.file = parallel:::getClusterOption("outfile", options)
+        if (class(options.out.file) == "lazy")
+        {
+            options.copy = parallel:::addClusterOptions(options,
+                list("outfile" = lazy_eval(options.out.file,
+                                           list(worker.id   = i,
+                                                worker.name = names[i]))))
+        }
+
+        tryCatch({
+            cl.node =
+                evalWithTimeout(parallel:::newPSOCKnode(names[[i]],
+                                                        options = options.copy,
+                                                        rank = i),
+                                timeout = connection.timeout,
+                                onTimeout = "error")
+            cl[[i]] = cl.node
+            flog.info("OK")},
+            error = function(e) {
+                if ("TimeoutException" %in% class(e))
+                {
+                    flog.warn("Timeout")
+                } else {
+                    stop.script(e)
+                }
+            }
+        )
+    }
+
+    cl.filtered = list()
+    i = 1
+    for (j in seq_along(cl))
+    {
+        if (!is.null(cl[[j]]))
+        {
+            cl.filtered[[i]] = cl[[j]]
+            i = i + 1
+        }
+    }
+
+    if (length(cl) != length(cl.filtered))
+    {
+        flog.warn(paste("Unable to connect to", length(cl) - length(cl.filtered),
+                        "nodes"))
+    }
+
+    if (length(cl.filtered) == 0)
+    {
+        stop.script("No remote workers")
+    } else {
+        flog.info(paste("Working on", length(cl.filtered), "nodes"))
+    }
+
+    class(cl.filtered) = c("SOCKcluster", "cluster")
+    cl.filtered
+}
+
+stop.cluster = function(cl.to.stop = cl)
+{
+    flog.info("Workers shut down")
+
+    foreach::registerDoSEQ()
+    parallel::stopCluster(cl.to.stop)
+}
diff --git a/utils.R b/utils.R
new file mode 100644
index 0000000..64ae030
--- /dev/null
+++ b/utils.R
@@ -0,0 +1,26 @@
+
+# additional functions
+
+setup.logger = function(output.file, overwrite.existing.files)
+{
+    if (overwrite.existing.files & file.exists(output.file))
+    {
+        file.remove(output.file)
+    }
+
+    invisible(flog.appender(appender.tee(output.file)))
+}
+
+
+stop.script = function(error)
+{
+    if (is.character(error))
+    {
+        flog.error(error)
+    } else {
+        flog.error(getMessage(error))
+    }
+
+    throw(error)
+}
+