Sorting Processes by CPU and Memory usage

To identify processes causing high CPU usage

ps aux --sort -pcpu | head
ps -aeo pcpu,pid,user,args | sort -k1 -r | head -10

To identify processes causing memory usage

ps aux --sort -rss | head
top -b -n 1 -d 3 -m
ps -Ao vsz,args | sort -n

ps -e -o pid,vsz,comm= | sort -n -k 2

To find CPU usage of threads in a process like Java(Tomcat)

ps -mo pid,lwp,stime,time,cpu -C java