Failed to initialize server object 'servicename.MapServer': 0x80004005: Unspecified error

Error Message

When experiencing performance problems with a particular service, the following messages pertaining to this specific service are found in the ArcGIS Server logs:

Error:   
<Msg time="x" type="SEVERE" code="8003" source="servicename.MapServer" process="x" thread="x" methodName="" machine="x" user="" elapsed="">Failed to initialize server object 'servicename.MapServer': 0x80004005: Unspecified error </Msg>

<Msg time="x" type="SEVERE" code="8274" source="servicename.MapServer" process="x" thread="x" methodName="" machine="x" user="" elapsed="">Failed to construct instance of service 'servicename.MapServer  Unspecified error</Msg>

<Msg time="x" type="SEVERE" code="9000" source="Rest" process="x" thread="x" methodName="" machine="x" user="" elapsed="">Error performing query operation Error handling service request :0x80004005 - Unspecified error</Msg>

Cause

Seeing the following severe errors in a succession in the ArcGIS Server logs indicates that a service is set to low isolation. In the ArcGIS Server documentation for tuning and configuring services, an explanation of the differences between high and low isolation are provided.

Solution or Workaround

Esri recommends using high isolation. As documented in the following web help link, low isolation does increase the amount of concurrent instances supported with a single process and uses less memory on the server, but these instances are destroyed if the process experiences a crash or shutdown.

To switch a service from low isolation to high isolation in ArcGIS Server 10.5.x, follow the instructions provided below.

Note:
To switch a service from low isolation to high isolation in ArcGIS for Server 10.4.x and previous versions, use the workflow below or make the change in ArcGIS Server Manager.

1. Open ArcCatalog, or expand the Catalog pane in ArcMap to make an administrative connection to the server via GIS Servers.

   Note:
   A publisher connection also works if the service in question was published by the user.

2. Right-click the name of the service that must have its isolation settings changed, and click Service Properties.
3. In the Service Editor window, click the Processes tab.
4. Where there is a drop-down for the setting Run instances of this configuration:, select In a separate process for each instance (high isolation).
   
   
    
5. Click OK.