Linux: How to monitor the memory in use

One web service occurred not normal few times.

Microsoft Azure Metrics (on Web Based. Mobile apps not yet available) showed that had memory overload.

Set up cron to monitor memory for more detail to identify what process brought it.

More important, logging it.

So could follow this question.

# ps -eo pid,ppid,cmd,%mem,%cpu --sort=-%mem | head | sed "s#^#$(date +%Y/%m/%d/%H:%M) #" >> /var/log/memory.log

# crontab -e

*/1 * * * * /bin/ps -eo "pid,ppid,cmd,\%mem,\%cpu" --sort=-"\%mem" | head | sed "s#^#$(date +\%Y/\%m/\%d/\%H:\%M) #" >> /var/log/memory.log

Edit /etc/logrotate.d/memory

/var/log/memory.log {

  rotate 7

  size 50M

  daily

  compress

  delaycompress

  notifempty

  missingok

}

Update