Portal for ArcGIS: Hosted/<Feature_Service>/FeatureServer: The connection attempt failed

Error Message

In ArcGIS Enterprise, when attempting to load a hosted feature layer in Portal for ArcGIS Map Viewer or ArcGIS Dashboards, the error message below is intermittently returned.

Error:
Hosted/<Feature_Service>/FeatureServer: The connection attempt failed.

In some cases, the error message described below is present in the hosting ArcGIS Server logs in addition to the previous error message.

Error:
Hosted/<Feature_Service>/FeatureServer: Connection to <Machine_Name>:9876 refused. Check that the hostname and port are correct and that the postmaster is accepting TCP/IP connections.

Cause

The antivirus program installed on the machine interrupts the communication between ArcGIS Server and the relational data store.

Solution or Workaround

Warning:   
Consult the organization's IT personnel before proceeding with the workarounds.

Configure antivirus exceptions

Configure the antivirus software to exclude certain processes or directories related to ArcGIS. Refer to Microsoft: Add an exclusion to Windows Security for instructions. Download the PDF file, PDF: Considerations for configuring antivirus software for ArcGIS Enterprise hosts, for additional information. Exempt the following directories:

• ArcGIS Server directories:

\arcgisserver\directories\arcgiscache\

\arcgisserver\directories\arcgisjobs\

\arcgisserver\directories\arcgisoutput\

\arcgisserver\directories\arcgissystem\

\arcgisserver\config-store\

• ArcGIS DataStore directories:

\arcgisdatastore\pgdata\

\arcgisdatastore\nosqldata\

• Portal for ArcGIS directories:

\arcgisportal\temp\

\arcgisportal\dsdata\

\portalforarcgis\content\arcgisportal\db\

\portalforarcgis\content\arcgisportal\index\

Note:
After completing the necessary tasks, reinstate the exempted directories.

Disable or remove the antivirus program

Warning:
Proceed with the following workaround with caution, as disabling or removing the antivirus program potentially exposes the machine to security risks.

Disable or remove the antivirus program on the ArcGIS Enterprise machines. Refer to Microsoft: Turn off Defender antivirus protection in Windows Security for instructions.

If the antivirus is a third-party program, temporarily disable it.

Note:
After completing the necessary tasks, reactivate the antivirus program, as it safeguards the machine from potential security threats. To reactivate Microsoft Defender, refer to Microsoft: Turn on Microsoft Defender Antivirus for instructions. If a third-party antivirus was disabled, reenable it.