Real Time Co-editing of High Vertex Count Geometries Using OpenLayers and CRDTs - a Performance Analysis

Abstract. When manipulating high vertex count geometries, real-time collaborative editing of geospatial data presents significant performance challenges. This paper investigates the performance of a CRDT (Conflict-free Replicated Data Type) based real-time geospatial co-editor implemented in JavaScript using OpenLayers and Reference CRDTs. It extends previous work by evaluating system responsiveness under increasing data complexity and concurrent user load. To this end, large polygons with 100K, 200K, and 300K vertices were co-edited by up to 60 concurrent users across varying hardware platforms. Key performance bottlenecks were identified in the GUI coupling and CRDT integration mechanisms. While the core CRDT mechanisms remained performant, GUI limitations emerged as the primary constraint at higher vertex counts. A modified downstream processing approach was implemented to mitigate the detected GUI limitations. The results suggest that, despite some GUI limitations, CRDT-based architectures are viable for real-time co-editing of high vertex count geometries even under increased active user counts.