Command line tools for system and process management

The command line is an invaluable tool for system monitoring. In this section, we'll go over a few basic GNU/Linux command line utilities for system and process management. Knowing these tools is essential for anyone managing an Elasticsearch cluster on GNU/Linux.

top

The top command lists processes with the highest CPU and memory. This tool is useful to determine whether a process other than Elasticsearch is hogging resources, or to check whether Elasticsearch is using an abnormal amount of CPU or memory.

The top command refreshes automatically, so you only have to run it once and watch.

When running the command, you should see the following result:

The top command

Tip

Press Shift+M while top is running to sort processes by those using the most memory instead of CPU.

tail

The tail -f command is useful for viewing log files in real time. Use it to view Elasticsearch log files as follows:

tail -f /var/log/elasticsearch/*

"tailing" Elasticsearch log...