2. NGINX Amplify Agent

2.1. What Operating Systems are Supported?

The agent is currently officially packaged and supported for the following Linux flavors only:
  • Ubuntu 14.04 "trusty" (i386/amd64/arm64)
  • Ubuntu 16.04 "xenial" (i386/amd64/arm64)
  • Ubuntu 17.10 "artful" (i386/amd64)
  • Ubuntu 18.04 "bionic" (amd64)
  • Debian 8 "jessie" (i386/amd64)
  • Debian 9 "stretch" (i386/amd64)
  • RHEL/CentOS/OEL 6 (i386/amd64)
  • RHEL/CentOS/OEL 7 (i386/amd64)
  • Amazon Linux 2017.09 (amd64)
Other OS and distributions below are not fully supported yet (and no agent packages are available), however you can grab a specialized install script here and see if it works for you. Run install-source.sh (as root) instead of install.sh and follow the dialog. You can copy the API key from the Amplify UI (find it in the Settings or in the New System pop-up).
  • FreeBSD 10, 11
  • SLES 12
  • Alpine 3.3
  • Fedora 24, 26
Feel free to submit an issue or a PR if you find something that has to be fixed.
We also have an experimental Ebuild for Gentoo.

2.2. What Version of Python is Required?

NGINX Amplify Agent will work with Python 2.6 and 2.7.
Python 3 is not supported yet.

2.3. How Do I Start to Monitor My Systems with NGINX Amplify?

  1. Download and run the install script.
    # curl -sS -L -O \ https://github.com/nginxinc/nginx-amplify-agent/raw/master/packages/install.sh && \ API_KEY='YOUR_API_KEY' sh ./install.sh
    where YOUR_API_KEY is a unique API key assigned when you create an account with NGINX Amplify. You can also find the API key in the Account menu.
  2. Verify that the Agent has started.
    # ps ax | grep -i 'amplify\-' 2552 ? S 0:00 amplify-agent
For manual installation, please check the user guide here.

2.4. What Do I Need to Configure the NGINX Amplify Agent to Properly Report Metrics?

After you install and start the agent, normally it should just start reporting right away, pushing aggregated data to the Amplify backend at regular 1 minute intervals. It'll take about a minute for the new system to appear in the Amplify web interface.
If you don't see the new system or NGINX in the web interface, or (some) metrics aren't being collected, please check the following:
  1. The Amplify Agent package has been successfully installed, and no warnings were seen upon the installation.
  2. The amplify-agent process is running and updating its log file.
  3. The agent is running under the same user as your NGINX worker processes.
  4. The NGINX is started with an absolute path. Currently the agent can't detect NGINX instances launched with a relative path (e.g. "./nginx").
  5. The user ID that is used by the agent and the NGINX , can run ps(1) to see all system processes. If ps(1) is restricted for non-privileged users, the agent won't be able to find and properly detect the NGINX master process.
  6. The time is set correctly. If the time on the system where the agent runs is ahead or behind the world's clock, you won't be able to see the graphs.
  7. stub_status is properly configured, and the stub_status module is included in the NGINX build (this can be checked with nginx -V).
  8. NGINX access.log and error.log files are readable by the user nginx (or by the user set in NGINX config).
  9. All NGINX configuration files are readable by the agent user ID (check owner, group and permissions).
  10. Extra configuration steps have been performed as required for the additional metrics to be collected.
  11. The system DNS resolver is correctly configured, and receiver.amplify.nginx.com can be successfully resolved.
  12. Oubound TLS/SSL from the system to receiver.amplify.nginx.com is not restricted. This can be checked with curl(1). Configure a proxy server for the agent if required.
  13. selinux(8), apparmor(7) or grsecurity are not interfering with the metric collection. E.g. for selinux(8) check /etc/selinux/config, try setenforce 0 temporarily and see if it improves the situation for certain metrics.
  14. Some VPS providers use hardened Linux kernels that may restrict non-root users from accessing /proc and /sys. Metrics describing system and NGINX disk I/O are usually affected. There is no an easy workaround for this except for allowing the agent to run as root. Sometimes fixing permissions for /proc and /sys/block may work.

2.5. How Do I Verify that NGINX Amplify Agent Is Correctly Installed?

  1. On Ubuntu/Debian use:
    # dpkg -s nginx-amplify-agent
  2. On CentOS and Red Hat use:
    # yum info nginx-amplify-agent

2.6. How Can I Update NGINX Amplify Agent?

  1. On Ubuntu/Debian use:
    # apt-get update && \ apt-get install nginx-amplify-agent
  2. On CentOS use:
    # yum makecache && \ yum update nginx-amplify-agent

2.7. What System Resources are Required?

We work very hard to make the agent consume as little memory and CPU as possible. Normally it should be under 10% of CPU usage and a few dozen MBs of RSS memory. If you notice any anomalies in the system resource consumption, please fill in a support ticket through Intercom.

2.8. How Do I Restart NGINX Amplify Agent?

It's as simple as
# service amplify-agent restart

2.9. How Can I Uninstall NGINX Amplify Agent?

  1. On Ubuntu/Debian use:
    apt-get remove nginx-amplify-agent
  2. On CentOS and Red Hat use:
    yum remove nginx-amplify-agent

2.10. How Can I Override System Hostname?

If the agent is not able to determine the system's hostname, you can define it manually in /etc/amplify-agent/agent.conf
Check for the following section, and fill in the desired hostname:
[credentials] .. hostname = myhostname1
The hostname should be something real — the following aren't valid hostnames:
  • localhost
  • localhost.localdomain
  • localhost6.localdomain6
  • ip6-localhost

2.11. How Can I Override the User ID for the Agent to Use?

Please check the following section of the NGINX Amplify public documentation.

2.12. Can I Use NGINX Amplify Agent with Docker?

Although the support for a Docker environment is currently experimental, in general the answer is yes. Please check the following part of the agent repository to find out more.