Applications Systems

An unwanted host which has been removed or deleted is reappearing in the DPM Inventory

Hosts that you no longer want to monitor may reappear in DPM unexpectedly after deleting the host from the Inventory page or shutting down the agent. Depending on the kind of installation used to monitor the host, you must follow a unique uninstallation process.

First published date

5/15/2020 3:46 PM

Last published date

6/4/2020 10:31 AM

Overview

Hosts can be added to DPM in a number of ways, including automated discovery of the databases and manually specifying the address of the database to monitor using a configuration file. With the exception of Off-Host installations added only through the Add New Host wizard, certain additional steps need to be done after deleting the Host through the Inventory page.

Product section

Database Performance Monitor

Cause

There are three ways that the DPM agent can begin to monitor a database:
  • It can find the database automatically, using a process called "auto-discovery." This is done when the agent is installed on the same server as the database using a basic On-Host installation.
  • The address of the database can be provided to the "Add New Host" installation wizard during a basic Off-Host installation.
  • The address of the database can be provided in a configuration file or environment variable using the drv-manual-host-uri option, which is common in both container installations as well as certain other advanced setups.
The agent will continue to automatically re-discover a local database for as long as the agent is installed on that server. Similarly, if an agent is configured to monitor a database using a configuration file or environment variable, it will continue to re-add that database to the Inventory for as long as the configuration option contains the database address. Deleting a database from the Inventory page will only permanently remove the database if the address was provided to the Add New Host wizard (bullet two above). Deleting the host instructs the backend that the database was removed, but this does not override auto-discovery or local configuration, which will re-add the database during the agent's next discovery round (every ten minutes).

Resolution

To permanently remove the Host from DPM, one of the following must be done depending on installation method:
  • If the database is installed using the drv-manual-host-uri option (or the environment variable VC_DRV_MANUAL_HOST_URI), such as through a container or other automated or scripted setup, the host will be reinstalled the next time the supervisor checks its configuration (every ten minutes). In order to remove this host, you need to remove the URI of the database from the drv-manual-host-uri option.
  • If the database was detected automatically (auto-discovered) by the DPM agent, you must uninstall the agent from the server using the uninstall instructions. However, if you have a database on that host you would like to monitor, and it is only one of the hosts which should be removed, you will need to follow the advanced installation instructions for ignoring auto-detected hosts.
  • If the database was added through the Off-Host workflow in the Add New Host wizard, you can simply delete the host from the Inventory page.