calculate_concurrency() {

MEMORY_AVAILABLE=${MEMORY_AVAILABLE-$(detect_memory 512)}

WEB_MEMORY=${WEB_MEMORY-512}

WEB_CONCURRENCY=${WEB_CONCURRENCY-$((MEMORY_AVAILABLE/WEB_MEMORY))}

if (( WEB_CONCURRENCY < 1 )); then

WEB_CONCURRENCY=1

elif (( WEB_CONCURRENCY > 32 )); then

WEB_CONCURRENCY=32

fi

WEB_CONCURRENCY=$WEB_CONCURRENCY

}

log_concurrency() {

echo "Detected $MEMORY_AVAILABLE MB available memory, $WEB_MEMORY MB limit per process (WEB_MEMORY)"

echo "Recommending WEB_CONCURRENCY=$WEB_CONCURRENCY"

}

detect_memory() {

local default=$1

local limit=$(ulimit -u)

case $limit in

256) echo "512";;

512) echo "1024";;

32768) echo "6144";;

*) echo "$default";;

esac

}

export PATH="$HOME/.heroku/node/bin:$HOME/bin:$HOME/node_modules/.bin:$PATH"

export NODE_HOME="$HOME/.heroku/node"

calculate_concurrency

log_concurrency

export MEMORY_AVAILABLE=$MEMORY_AVAILABLE

export WEB_MEMORY=$WEB_MEMORY

export WEB_CONCURRENCY=$WEB_CONCURRENCY