# load\_average\_15

**URL:** <https://community.netdata.cloud/t/load-average-15/2497>\
**Category:** Alerts\
**Created:** [February 1, 2022, 8:38am UTC](https://community.netdata.cloud/t/load-average-15/2497 "2022-02-01T08:38:11Z")\
**Posts on this page:** 1\
**Page:** 1

<div class="post-metadata">

**Author:** ![Ancairon](https://yyz1.discourse-cdn.com/flex029/user_avatar/community.netdata.cloud/ancairon/32/1001_2.png) [@Ancairon](https://community.netdata.cloud/u/Ancairon)\
**Post date:** [February 1, 2022, 8:38am UTC](https://community.netdata.cloud/t/load-average-15/2497/1 "2022-02-01T08:38:11Z")

</div>

# load\_average\_15

## OS: Linux

This alarm calculates the system `load average` (CPU and I/O demand) over the period of fifteen minutes.  
If you receive this alarm, it means that your system is “overloaded.”

The alert gets raised into warning if the metric is 2 times the expected value and cleared if  
the value is 1.75 times the expected value.

For further information on how our alerts are calculated, please have a look at our [Documentation](https://learn.netdata.cloud/docs/agent/health/reference#expressions).

> **What does "load average" mean?**
>
> The term `system load average` on a Linux machine, measures the **number of threads that are currently working and those waiting to work** (CPU, disk, uninterruptible locks) [1](https://www.helpsystems.com/resources/guides/unix-load-average-part-1-how-it-works) [2](https://www.helpsystems.com/resources/guides/unix-load-average-part-2-not-your-average-average) .  
> So simply stated: **System load average measures the number of threads that aren’t idle.**

> **What does "overloaded" mean?**
>
> Andre Lewis explains the term “overloaded” by using an example in his Blog post “Understanding Linux CPU  
> Load - when should you be worried?” [3](https://scoutapm.com/blog/understanding-load-averages)   
> You can click on the footnote or find it in our links section.
> 
> Let’s look at a single core CPU system and think of its core count as car lanes on a bridge. A car represents a process in this example:
> 
> - On a 0.5 load average, the traffic on the bridge is fine, it is at 50% of its capacity.
> - If the load average is at 1, then the bridge is full, and it is utilized 100%.
> - If the load average gets to 2 (remember we are on a single core machine), it means that there is one car lane that is passing the bridge. However, there is **another** full car lane that waits to pass the bridge.
> 
> So this is how you can imagine CPU load, but keep in mind that `load average` counts also I/O demand, so there is an analogous example there.

  

> **References and Sources**
>
> 1. [UNIX Load Average Part 1: How It Works](https://www.helpsystems.com/resources/guides/unix-load-average-part-1-how-it-works)
> 2. [UNIX Load Average Part 2: Not Your Average Average](https://www.helpsystems.com/resources/guides/unix-load-average-part-2-not-your-average-average)
> 3. [Understanding Linux CPU Load](https://scoutapm.com/blog/understanding-load-averages)
> 4. [Linux Load Averages: Solving the Mystery](https://www.brendangregg.com/blog/2017-08-08/linux-load-averages.html)
> 5. [Understanding Linux Process States](https://access.redhat.com/sites/default/files/attachments/processstates_20120831.pdf)

### Troubleshooting Section

> **Determine if the problem is CPU or I/O bound**
>
> First you need to check if you are running on a CPU load or an I/O load problem.
> 
> 1. To get a report about your system statistics, use `vmstat` (or `vmstat 1`, to set a delay between updates in seconds):
> 
> ```auto
> root@netdata~ # vmstat 
> procs -----------memory---------- ---swap-- -----io---- -system-- ------cpu-----
> r b swpd free buff cache si so bi bo in cs us sy id wa st
> 8 0 1200384 168456 48840 1461540 4 14 65 51 334 196 3 1 95 0 0
> 
> ```
> 
> The `procs` column, shows:  
> r: The number of runnable processes (running or waiting for run time).  
> b: The number of processes blocked waiting for I/O to complete.
> 
> 1. List your currently running processes using the `ps` command:
> 
> The `grep` command will fetch the processes that their state code starts either with R (running or runnable (on run queue)) or D(uninterruptible sleep (usually IO)).
> 
> 1. Minimize the load by closing any unnecessary main consumer processes. We strongly advise you to double-check if the process you want to close is necessary.

> **Check per-process CPU/disk usage to find the top consumers**
>
> 1. To see the processes that are the main CPU consumers, use the task manager program `top` like this:
> 
> 2. Use `iotop`:  
> `iotop` is a useful tool, similar to `top`, used to monitor Disk I/O usage, if you don’t have it,  
> then [install it](https://www.tecmint.com/iotop-monitor-linux-disk-io-activity-per-process/)
> 
> Note: If `iotop` is not installed on your machine, please refer to the [install instructions](https://www.tecmint.com/iotop-monitor-linux-disk-io-activity-per-process/)
> 
> 1. Minimize the load by closing any unnecessary main consumer processes. We strongly advise you to double-check if the process you want to close is necessary.