Check DB Connection Count for Processes on Linux

Do you know how many DB connections does your process obtain? How to locate the culprit process if your database server reaches its max connections limit unexpectly? It is easy to find it out on Linux just by a few commands

Get Total Connection Count for All Processes

netstat -ap | grep [database_host] | awk '{print $7}' | awk -F '/' '{print $1}' | grep -v '-' | sort -n | uniq -c | awk '{s+=$1} END {print s}'

List All Processes Connect to Database

netstat -ap | grep [database_host] | awk '{print $7}' | awk -F '/' '{print $1}' | grep -v '-' | sort -n | uniq | xargs ps wwp

List Connection Count for Each Process

paste -d ':' <(netstat -ap | grep [database_host] | awk '{print $7}' | awk -F '/' '{print $1}' | grep -v '-' | sort -n | uniq -c | awk '{print $1}') <(netstat -ap | grep [database_host] | awk '{print $7}' | awk -F '/' '{print $1}' | grep -v '-' | sort -n | uniq | xargs ps --no-headers wwp)

List Connection Count for Each Process (Simplified)

paste  <(netstat -ap | grep [database_host] | awk '{print $7}' | awk -F '/' '{print $1}' | grep -v '-' | sort -n | uniq -c | awk 'BEGIN {print "COUNT"} {printf "%5s\n", $1}') <(netstat -ap | grep [database_host] | awk '{print $7}' | awk -F '/' '{print $1}' | grep -v '-' | sort -n | uniq | xargs ps wwp |  awk '{printf "%-8s", $1; print $NF}')