The AppSignal agent collects various system metrics, which allows you to correlate performance issues and errors to abnormal host metrics. This data is available in the Host metrics section in the app overview, which allows you to inspect and compare multiple hosts. We also show a host metrics overview on the sample detail page for error and performance incidents.
For a preview of how host metrics look in the AppSignal interface, please see our host metrics tour page.
Note: This feature is available in these packages:
- Ruby: gem version
1.2and newer. Enabled by default since version
- Elixir: package version
0.10.0and newer. Enabled by default since version
- Node.js: all package versions.
Note: This feature is not available on the following architectures:
- macOS/OSX (
The following host metrics are collected by the AppSignal agent for every minute on your system.
User, nice, system, idle and iowait in percentages.
Read more about CPU metrics in our academy article.
|Load average||1 minute load average on the host.|
|Memory usage||Available, free and used memory. Also includes swap total and swap used.|
|Disk usage||Percentage of every disk used.|
|Disk IO||Throughput of data read from and written to every disk.|
|Network traffic||Throughput of data received and transmitted through every network interface.|
The AppSignal agent reports the following information of the host. Once received this metadata is shown on the host metrics index page per host to provide more detail of all hosts running an app. Use this metadata to spot any differences between hosts that could cause differences in behavior.
- Host architecture, 32 or 64-bit.
- Operating System, either Linux, macOS or Windows.
- Operating System Distribution, for Linux this reports Ubuntu, Fedora, etc.
- Operating System version, the version of the Operating System.
- Kernel version, for Linux this reports the installed kernel version.
This metadata is collected by default. To disable it, use the
send_environment_metadata configuration option, for Ruby.
To use host metrics on Heroku, head to the Heroku host metrics page.
To use host metrics on (Docker) containers, head to the container host metrics page.
Dokku is very much like Heroku's setup. This is why the AppSignal agent thinks it's running on Heroku. The AppSignal integration turns off host metrics for Heroku automatically, as Heroku doesn't expose runtime metrics for LXC containers. Instead, we recommend using our Logplex drain.
Since Dokku emulates Heroku's environment by setting the
DYNO environment variable, host metrics are disabled by default on Dokku as well. To turn them on anyway, you can unset the
DYNO environment variable for your app. This will make AppSignal not recognize the system as Heroku.
Please note that unsetting the
DYNO environment variable can have other effects on your Dokku system. Please check with Dokku if this is possible with your setup.