Feature Layer Flickering While Zooming with Koop GeoServices Source

[conmar5]

Feature Layer Flickering While Zooming with Koop GeoServices Source

Description

We are experiencing significant "flickering" behavior when zooming in and out on ArcGIS web maps that use feature layers with Koop GeoServices as the data source. This flickering manifests as refreshing or reloading of features during zoom interactions.

Observations

• Comparison with Other Sources:

  • This issue does not occur with feature layers containing identical data but sourced from ArcGIS Online (AGOL).
  • WMS layers from GeoServer are also unaffected.
  • An example map comparing koop-geojson, koop-pg and AGOL is available at the link below. Rapidly zooming in and out on the map results in features "flickering" or reloading for both koop layers.
    https://main.d3ekp4g76pjmch.amplifyapp.com/

• Input Providers:

  • The issue persists regardless of the Koop provider used (tested with koop-provider-pg and koop-provider-file-geojson).

• Suspected Cause:

  • We suspect this behavior is related to differences in layer metadata. As you will see in the gifs below "tiles" are reloaded for koop layers but don't appear to be for AGOL layers. In the gifs below the queries are all cached in the browser also so the issue is not network related.

Potential Cause

The problem appears to stem from requests being canceled as the map's scale and extent change. However, we are unable to determine why layers sourced from AGOL exhibit significantly greater stability compared to those from Koop GeoServices.

Environment

• ArcGIS Web Map
• Feature Layers via Koop GeoServices

Request for Assistance

We are looking for insights or guidance on:

1. Whether there are specific metadata configurations required for Koop GeoServices layers to ensure stability.
2. Any optimizations or configurations in Koop that could address this issue.
3. Troubleshooting steps to better understand and resolve the problem.

Any help or suggestions would be greatly appreciated! We're happy to fix and make a pull request if it's an issue with Koop.