Host Monitoring Agent

The Host Monitoring Agent monitors the state of a host machine. For AppMon 6.5 and later, it can also monitor availability of any process running on the host. For further information on process availability monitoring see information on configuration of hosts/host groups on the Infrastructure page.

However, in most cases you don't need this Agent, as almost any active Agent delivers those metrics. The exceptions are:

The Node.js Agent doesn't deliver host metrics.
The Web Server Master Agent deliver host metrics only when a slave Agent is connected.

With many Agents on one machine, you may want to switch off delivery of host monitoring data from non-Host-Agents to reduce traffic from Agent to Collector. Contact support to develop the best strategy.

Installation and configuration

Windows

Full install package

The Windows full install package installs the Host Agent, but its service is not registered, keeping the Agent inactive, due to the potential redundant Host Agent role, mentioned previously. You can register the Host Agent with "<DT_HOME>\agent\lib\dthostagent" -service install command. Copy and paste this example to register the 32-bit Host Agent service from a 64-bit AppMon full installation:

"C:\Program Files\Dynatrace\Dynatrace 7.0\agent\lib\dthostagent" -service install

To unregister the Agent service, use this command:

sc delete "dynaTrace Host Agent7.0".

Agent-only installer

If you're using the Agent-only installer, you should select the Custom installation option during the process, and manually select the Host Agent for installation. This lets the Agent auto-start, which is useful for monitoring the machine with no other Agent running on it.

\*NIX

Installation

Use these commands:

cd /opt
java -jar <DownloadDir>/<dynatrace(Agent)Installer.jar>

The installer defaults to the current directory and asks if you want to change the destination. Make sure you have the correct permissions for installation and to write to the target location.

The <DT_HOME>/init.d/dynaTraceHostAgent shell script should be copied to or referenced in (link) /etc/init.d and added to the system boot by using something similar chkconfig or update-rc.d, depending on your distribution.

The <DT_HOME> directory is one of the following:

/opt/dynatrace-7.0 for full install package.
/opt/dynatrace-agent-7.0 for Agent-only installer.

These are default options. Actual directory is prompted during the installation.

Configuration

Configuration must be done by editing the <DT_HOME>/agent/conf/dthostagent.ini. The following configuration options are available:

Key	Default	Description
Name	host	Agent name, can be used to map an Agent to a specific Agent Group.
Server	localhost:9998	A standalone or embedded Collector to which this Agent should connect. The argument name `Server` stems from past releases when the Collector was Server-integrated. Most licenses allow only standalone Collectors, except for testing.
Loglevel	info	Defines log level.
ConsoleLoglevel	info	Defines console log level.
LogfilePath	<agent location>/log	Specifies a custom log file.
OverrideHostname	<not set>	Specifies a custom hostname. If set the Agent is unable to detect the host name automatically.
usessl	false	Enables SSL encryption between the Agent and the Collector. Encrypted communication uses the same port as non-encrypted. To enable SSL you need to set this parameter as `true` before launching the Agent.

Example basic dthostagent.ini

The following is an example of the <DT_HOME>/agent/conf/dthostagent.ini file. This file configures the Host Monitoring Agent named host (default) to connect to the AppMon Collector with the fully qualified name dtcollector.localdomain.com on port 9998, using the SSL connection.

Name host
Server dtcollector.localdomain.com:9998
usessl true

Agent bulk installation

To monitor a large number hosts, you can automate the Host Agent deployment.

Windows

Perform a custom installation with the full or Agent-only .msi, or use dthostagent.exe, dtagentcore.dll, and dthostagent.ini in the directory structure.

If you use the installer with msiexec /passive /i <path>\<dynaTraceInstallerFileName>.msi ADDLOCAL="HostAgent", then Host Agent registers as an auto-starting service with the default settings from dthostagent.ini. You can rewrite dthostagent.ini and un/register the service with the new arguments.

If you just use the .exe and .dll, you can write your own dthostagent.ini and register the service to auto-start with <DT_HOME>\agent\dthostagent.exe -service install.

*NIX

#extract dthostagent and libdtagentcore.so from agent/lib64/ in the jar
#extract init.d/dynaTraceHostagent from the jar

#mimic Agent directory structure on the host
mkdir dynatrace-agent-7.0.0
mkdir dynatrace-agent-7.0.0/agent
mkdir dynatrace-agent-7.0.0/agent/lib64
mkdir dynatrace-agent-7.0.0/agent/conf

#copy dthostagent and libdtagentcore.so to agent/lib64/
#write a basic dthostagent.ini (see previous) to agent/conf
#copy dynaTraceHostagent shell script to /etc/init.d
#be sure the Name specified in dthostagent.ini is mapped in some tier to avoid an error message
#try the Agent before you add it to boot
#/etc/init.d/dynaTraceHostagent start
chkconfig add dynaTraceHostagent