Configure ActiveGate for memory dump storage

When your application experiences memory leaks or high object churn, it’s important that you get memory dumps so you can analyze these issues. In production environments, this is often a challenge when you can’t log into the environment and you have no other means of triggering memory dumps. Dynatrace enables you to both trigger and securely download memory dumps to the analysis tool of your choice. To enable memory dumps, you need to configure your ActiveGate as described below.

If you configure an ActiveGate to collect memory dumps, and then restart the ActiveGate service, all instances of OneAgent will automatically reconnect and recognize that the ActiveGate can now store memory dumps. From now on, whenever a memory dump is successfully triggered, the dump will be uploaded automatically to the correct ActiveGate. Once safely stored on the ActiveGate, the OneAgent deletes the local file from its storage.

Configuration steps

If you don’t already have an ActiveGate set up, you need to install an ActiveGate.

Customize your ActiveGate configuration

ActiveGate configuration (for example, proxy settings, or memory dump settings), is stored in config.properties and custom.properties files, located in the ActiveGate configuration directory.

The configuration file config.properties is overwritten during each update of ActiveGate. Thus, any customized settings stored in this file will be lost (with some exceptions). To avoid losing your customized settings with each update, store customized settings in the custom.properties file instead. Settings stored in this file take precedence over corresponding settings in config.properties, and the file is copied to the newly installed version of ActiveGate.

The custom.properties file will initially be empty. To specify customized settings, enter section names and include the properties within these sections. We recommend that you first locate the relevant section in the config.properties file and then copy the section title along with the names of the desired properties into custom.properties

Restart required

If you modify the custom.properties file, restart the ActiveGate to put your changes into effect.

Edit the custom.properties file of your ActiveGate.

This file is located in the config folder of your ActiveGate:

  • Linux systems:
    /var/lib/dynatrace/gateway/config
  • Windows systems:
    %PROGRAMDATA%\dynatrace\gateway\config

Note: On Windows, the %PROGRAMDATA% directory is usually hidden for non-privileged users. Therefore you cannot select it by browsing through folders. Instead, to access the folder, paste the folder path directly into a Windows Explorer address box.

Create the [collector] section (if it doesn't already exist). Specify the DumpSupported property in this section and set the value to true.

[collector]
DumpSupported = true

optional
By default, ActiveGate saves memory dumps in %PROGRAMDATA%\dynatrace\gateway\dump on Windows and in /var/lib/dynatrace/gateway/dump on Linux. These directories need to have appropriate permissions set.

To specify a custom path, create the [dump] section (if it doesn't already exist). Specify the dumpDir property in this section. For example:

[dump]
dumpDir = dump

The dumpDir property can be a relative path, for example, dumpDir = mydir. In this case, the directory will be a subdirectory of the default location. It can also be an absolute path, for example, dumpDir = C:\data\memory-dumps.

Create the folder, if it does not already exist, and make sure that it has correct access permissions for the user running the ActiveGate service. This is by default dtuserag for Linux, and Local Service for Windows:

Also in the [dump] section, specify the following properties:

  • maxSizeGb maximum size, in GB, for stored memory dump
  • maxAgeDays maximum age, in days, for keeping stored memory dumps
  • maxConcurrentUploads maximum number of concurrent file uploads supported

Restart the ActiveGate.