Question

Droplet experiencing high load averages during low CPU usage

I have a Ubuntu 18.04 droplet that occasionally experiences high load averages for brief periods, but the DO monitoring charts show low and steady CPU usage, steady disk I/O, steady traffic, and a small bump in RAM (probably due to extra apache processes waiting to run). So, everything looks normal except for the load averages. If the load averages go up into the 20s then I can see significant impact on page load times.

These episodes are not associated with high traffic, and they don’t normally last for more than a few minutes so it’s hard for me to catch them as they’re occurring. However, the one time I managed to do so I used the “top” command and saw extra apache processes (as expected during high load), but nothing else looked unusual. Nothing suspicious appears in syslog.

Any recommendations on what I need to do to troubleshoot this problem?

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Hello, @businessbcbdbe0eab0de5765a

What you can do is to check the Apache error log and see if the Apache workers have been exceeded as this will explain the spikes in the memory usage. You can check this with the following command:

grep -i workers $APACHE_LOG_DIR (usually it’s /var/log/apache2/error.log)

If the apache workers have been exceeded then you can tweak the value in the apache configuration in order to sort the issue. The exact value you need to look for is MaxRequestWorkers

I will also recommend you to check on this tutorial as you may find it useful:

https://www.digitalocean.com/community/tutorials/how-to-monitor-cpu-use-on-digitalocean-droplets

Hope this helps.

Regards, Alex