SignalFx Smart Agent

The SignalFx Smart Agent is a metric agent written in Go for monitoring infrastructure and application services in a variety of different environments. It is meant as a successor to our previous collectd agent, but still uses that internally on Linux -- so any existing Python or C-based collectd plugins will still work without modification. On Windows collectd is not included, but the agent is capable of running python based collectd plugins without collectd. C-based collectd plugins are not available on Windows.

• Concepts
• Installation
• Configuration
• Logging
• Proxy Support
• Diagnostics
• Development

Concepts

The agent has three main components:

1. Observers that discover applications and services running on the host
2. Monitors that collect metrics, events, and dimension properties the host and applications
3. The Writer that sends the metrics, events, and dimension updates collected by monitors to SignalFx.

Observers

Observers watch the various environments that we support to discover running services and automatically configure the agent to send metrics for those services.

For a list of supported observers and their configurations, see Observer Config.

Monitors

Monitors collect metrics from the host system and services. They are configured under the monitors list in the agent config. For application-specific monitors, you can define discovery rules in your monitor configuration. A separate monitor instance is created for each discovered instance of applications that match a discovery rule. See Auto Discovery for more information.

Many of the monitors are built around collectd, an open source third-party monitor, and use it to collect metrics. Some other monitors do not use collectd. However, either type is configured in the same way.

For a list of supported monitors and their configurations, see Monitor Config.

The agent is primarily intended to monitor services/applications running on the same host as the agent. This is in keeping with the collectd model. The main issue with monitoring services on other hosts is that the host dimension that collectd sets on all metrics will currently get set to the hostname of the machine that the agent is running on. This allows everything to have a consistent host dimension so that metrics can be matched to a specific machine during metric analysis.

Writer

The writer collects metrics emitted by the configured monitors and sends them to SignalFx on a regular basis. There are a few things that can be configured in the writer, but this is generally only necessary if you have a very large number of metrics flowing through a single agent.

Installation

The agent is available for Linux in both a containerized and standalone form. Whatever form you use, the dependencies are completely bundled along with the agent, including a Java JRE runtime and a Python runtime, so there are no additional dependencies required. This means that the agent should work on any relatively modern Linux distribution (kernel version 2.6+).

The agent is also available on Windows in standalone form. It contains its own Python runtime, but has an external depencency on the Visual C++ Compiler for Python 2.7 in order to operate. The agent supports Windows Server 2008 and above.

To get started deploying the Smart Agent directly on a host, see the Smart Agent Quick Install guide.

Deployment

We support the following deployment/configuration management tools to automate the installation process. See Bundles for a list of underlying packages for the agent.

Installer Script

For non-containerized environments, there is a convenience script that you can run on your host to install the agent package. This is useful for testing and trials, but for full-scale deployments you will probably want to use a configuration management system like Chef or Puppet.

Linux

You can view the source for the installer script and use it on your hosts by running:

curl -sSL https://dl.signalfx.com/signalfx-agent.sh > /tmp/signalfx-agent.sh
sudo sh /tmp/signalfx-agent.sh YOUR_SIGNALFX_API_TOKEN --realm YOUR_SIGNALFX_REALM

Windows

The Agent has two dependencies on Windows which must be satisfied before running the installer script.

• .Net Framework 3.5 (Windows 8+)
• Visual C++ Compiler for Python 2.7

The installer script is written for Powershell v3.0 and above and will not function correctly on earlier versions.

Once the dependencies have been installed, please run the installer script below. You can view the source for the installer script and use it on your hosts in powershell by running:

& {Set-ExecutionPolicy Bypass -Scope Process -Force; $script = ((New-Object System.Net.WebClient).DownloadString('https://dl.signalfx.com/signalfx-agent.ps1')); $params = @{access_token = "YOUR_SIGNALFX_API_TOKEN"; ingest_url = "https://ingest.YOUR_SIGNALFX_REALM.signalfx.com"; api_url = "https://api.YOUR_SIGNALFX_REALM.signalfx.com"}; Invoke-Command -ScriptBlock ([scriptblock]::Create(". {$script} $(&{$args} @params)"))}

The agent should be installed to \Program Files\SignalFx\SignalFxAgent, and the default configuration file should be installed at \ProgramData\SignalFxAgent.

Chef

We offer a Chef cookbook to install and configure the agent. See the cookbook source and on the Chef Supermarket.

Puppet

We also offer a Puppet manifest to install and configure the agent on Linux. See the manifest source and on the Puppet Forge.

Ansible

We also offer an Ansible Role to install and configure the Smart Agent on Linux. See the role source.

Salt

We also offer a Salt Formula to install and configure the Smart Agent on Linux. See the formula source.

Docker Image

See Docker Deployment for more information.

Kubernetes

See our Kubernetes setup instructions and the documentation on Monitoring Kubernetes for more information.

AWS Elastic Container Service (ECS)

See the ECS directory, which includes a sample config and task definition for the agent.

Bundles

We offer the agent in the following forms:

Debian Package

We provide a Debian package repository that you can make use of with the following commands:

curl -sSL https://dl.signalfx.com/debian.gpg > /etc/apt/trusted.gpg.d/signalfx.gpg
echo 'deb https://dl.signalfx.com/debs/signalfx-agent/final /' > /etc/apt/sources.list.d/signalfx-agent.list
apt-get update
apt-get install -y signalfx-agent

RPM Package

We provide a RHEL/RPM package repository that you can make use of with the following commands:

cat <<EOH > /etc/yum.repos.d/signalfx-agent.repo
[signalfx-agent]
name=SignalFx Agent Repository
baseurl=https://dl.signalfx.com/rpms/signalfx-agent/final
gpgcheck=1
gpgkey=https://dl.signalfx.com/yum-rpm.key
enabled=1
EOH

yum install -y signalfx-agent

Linux Standalone tar.gz

If you don't want to use a distro package, we offer a .tar.gz that can be deployed to the target host. This bundle is available for download on the Github Releases Page for each new release.

To use the bundle:

1. Unarchive it to a directory of your choice on the target system.

2. Go into the unarchived signalfx-agent directory and run bin/patch-interpreter $(pwd). This ensures that the binaries in the bundle have the right loader set on them since your host's loader may not be compatible.

3. Ensure a valid configuration file is available somewhere on the target system. The main thing that the distro packages provide -- but that you will have to provide manually with the bundle -- is a run directory for the agent to use. Since you aren't installing from a package, there are three config options that you will especially want to consider:

• internalStatusHost - This is the host name that the agent will listen on so that the signalfx-agent status command can read diagnostic information from a running agent. This is also the host name the agent will listen on to serve internal metrics about the agent. These metrics can can be scraped by the internal-metrics monitor. This will default to localhost if left blank.

• internalStatusPort - This is the port that the agent will listen on so that the signalfx-agent status command can read diagnostic information from a running agent. This is also the host name the agent will listen on to serve internal metrics about the agent. These metrics can can be scraped by the internal-metrics monitor. This will default to 8095.

• collectd.configDir - This is where the agent writes the managed collectd config, since collectd can only be configured by files. Note that this entire dir will be wiped by the agent upon startup so that it doesn't pick up stale collectd config, so be sure that it is not used for anything else. Also note that these files could have sensitive information in them if you have passwords configured for collectd monitors, so you might want to place this dir on a tmpfs mount to avoid credentials persisting on disk.

See the section on Privileges for information on the capabilities the agent requires.

3. Run the agent by invoking the archive path signalfx-agent/bin/signalfx-agent -config <path to config.yaml>. By default, the agent logs only to stdout/err. If you want to persist logs, you must direct the output to a log file or other log management system. See the signalfx-agent command doc for more information on supported command flags.

Windows Standalone .zip

If you don't want to use the installer script, we offer a .zip that can be deployed to the target host. This bundle is available for download on the Github Releases Page for each new release.

Before proceeding make sure the following requirements are met.

• .Net Framework 3.5 (Windows 8+)
• Visual C++ Compiler for Python 2.7

To use the bundle:

1. Unzip it to a directory of your choice on the target system.

2. Ensure a valid configuration file is available somewhere on the target system. The main thing that the installer script provides -- but that you will have to provide manually with the bundle -- is a run directory for the agent to use. Since you aren't installing from a package, there are two config options that you will especially want to consider:

• internalStatusHost - This is the host name that the agent will listen on so that the signalfx-agent status command can read diagnostic information from a running agent. This is also the host name the agent will listen on to serve internal metrics about the agent. These metrics can can be scraped by the internal-metrics monitor. This will default to localhost if left blank.

• internalStatusPort - This is the port that the agent will listen on so that the signalfx-agent status command can read diagnostic information from a running agent. This is also the host name the agent will listen on to serve internal metrics about the agent. These metrics can can be scraped by the internal-metrics monitor. This will default to 8095.

See the section on Privileges for information on the capabilities the agent requires.

3. Run the agent by invoking the agent executable SignalFxAgent\bin\signalfx-agent.exe -config <path to config.yaml>. By default, the agent logs only to stdout/err. If you want to persist logs, you must direct the output to a log file or other log management system. See the signalfx-agent command doc for more information on supported command flags.

4. You may optionally install the agent as a Windows service by invoking the agent executable and specifying a few command line flags. The examples below show how to do install and start the agent as a Windows service.

• Install Service

    PS> SignalFx\SignalFxAgent\bin\signalfx-agent.exe -service "install" -logEvents -config <path to config file>
  

• Start Service

    PS> SignalFx\SignalFxAgent\bin\signalfx-agent.exe -service "start"
  

Privileges

Linux

When using the host observer, the agent requires the Linux capabilities DAC_READ_SEARCH and SYS_PTRACE, both of which are necessary to allow the agent to determine which processes are listening on network ports on the host. Otherwise, there is nothing built into the agent that requires privileges. When using a package to install the agent, the agent binary is given those capabilities in the package post-install script, but the agent is run as the signalfx-agent user. If you are not using the host observer, then you can strip those capabilities from the agent binary if so desired.

You should generally not run the agent as root unless you can't use capabilities for some reason.

Windows

On Windows the agent must be installed and run under an administrator account.

Configuration

The agent is configured primarily from a YAML file. By default, the agent config is installed at and looked for at /etc/signalfx/agent.yaml on Linux and \ProgramData\SignalFxAgent\agent.yaml on Windows. This can be overridden by the -config command line flag.

For the full schema of the config, see Config Schema.

For information on how to configure the agent from remote sources, such as other files on the filesystem or KV stores such as Etcd, see Remote Configuration.

Logging

The default log level is info, which will log anything noteworthy in the agent without spamming the logs too much. Most of the info level logs are on startup and upon service discovery changes. debug will create very verbose log output and should only be used when trying to resolve a problem with the agent. You can change the log level with the logging: {level: info} YAML config option.

The agent will emit logs in either an unstructed text (default) or JSON format. You can configure it to emit JSON logs with the logging: {format: json} YAML config option.

Linux

Currently the agent only supports logging to stdout/stderr, which will generally be redirected by the init scripts we provide to either a file at /var/log/signalfx-agent.log or to the systemd journal on newer distros.

Windows

On Windows, the agent will log to the console when executed directly in a shell. If the agent is configured as a windows service, log events will be logged to the Windows Event Log. Use the Event Viewer application to read the logs. The Event Viewer is located under Start > Administrative Tools > Event Viewer. You can see logged events from the agent service under Windows Logs > Application.

Proxy Support

To use an HTTP(S) proxy, set the environment variable HTTP_PROXY and/or HTTPS_PROXY in the container configuration to proxy either protocol. The SignalFx ingest and API servers both use HTTPS. If the NO_PROXY envvar exists, the agent will automatically append the local services to the envvar to not use the proxy.

If the agent is running as a local service on the host, refer to the host's service management documentation for how to pass environment variables to the agent service in order to enable proxy support when the agent service is started.

For example, if the host services are managed by systemd, create the /etc/systemd/system/signalfx-agent.service.d/myproxy.conf file and add the following to the file:

[Service]
Environment="HTTP_PROXY=http://proxy.example.com:8080/"
Environment="HTTPS_PROXY=https://proxy.example.com:8081/"

Then execute systemctl daemon-reload and systemctl restart signalfx-agent.service to restart the agent service with proxy support.

Diagnostics

The agent serves diagnostic information on an HTTP server at the address configured by the internalStatusHost and internalStatusPort option. As a convenience, the command signalfx-agent status will read this server and dump out its contents. That command will also explain how to get further diagnostic information.

Also see our FAQ for more troubleshooting help.

Development

If you wish to contribute to the agent, see the Developer's Guide.