Web layers not drawing or drawing slowly

Description

When you open feature services, and observe that the features take a while to load in the map. When this occurs, you are able to view the attribute table of the feature services, but the features render or draw slowly. In some cases they may not draw at all.

This can occur with both referenced and hosted services.

Cause

When web layers fail to draw in ArcGIS Enterprise, the root cause is often tied to server resources, permissions, or database connectivity. Administrators should methodically evaluate the following common problem areas:

Folder permissions

• Verify that the ArcGIS Service account maintains the required permissions on critical directories.
• Be aware that permissions can sometimes be rolled back after updates or system changes, preventing services from accessing necessary resources.

Resource limitations

• Insufficient system resources (CPU, RAM, or storage) can directly impact the performance of web layers.
• Monitor resource utilization on both the ArcGIS Server machine and the underlying database servers to detect spikes or bottlenecks.

Database maintenance

• Neglecting regular maintenance on enterprise geodatabases can lead to degraded performance and service failures.
• Routine operations such as analyzing data, compressing, and rebuilding indexes are critical for sustaining service reliability.

Solution or Workaround

General troubleshooting steps

1. Restart services: Restart ArcGIS Server services.
   • For referenced services, also restart the underlying database service.
2. Verify permissions: Confirm that the ArcGIS Service account has Full Control permissions for the following directories:
   • C:\arcgisportal
   • C:\arcgisserver
   • C:\arcgisdatastore
   • C:\program files\ArcGIS
3. Check system resources: Ensure the machine has adequate RAM, storage capacity, and CPU availability.
   • If both referenced and hosted services are affected, consider increasing the heap size for ArcGIS Server (Windows). See: Change the heap size

Optimize services

• Review and optimize the service configuration to improve performance and stability.
  See: Tune and configure services
• Optimize service instances.
  See: Configure service instance settings

Troubleshooting referenced services

If the issue is limited to referenced services, the next step is to isolate whether the problem is at the service level or within the database:

• Connect directly to the feature class in the database from ArcGIS Pro.
  • If the issue occurs only when accessed via the service, it indicates a service-level issue.
  • If the problem persists when connected directly to the database, it is likely a database-related issue.

Database-specific solutions:

1. Verify database resources
   • Ensure the database server has sufficient resources (CPU, memory, and storage).
2. Perform database maintenance
   • Traditional versioned data
     • Run the Analyze Datasets tool
     • Run Compress 
     • Run the Rebuild Indexes tool, to make the reads on the table quicker.

   • Branched versioned data

     • Run the Analyze Datasets tool 
     • Run the Rebuild Indexes tool, to make the reads on the table quicker.