openlayers/ol3 — pull request #2801 by jmiller-boundless (2014-10-06 19:45:56+00:00)
Title: Using clustersource with a servervectorsource is not triggering feature ...

...loading from the server. The proposed change adds this.source_.loadFeatures(extent, resolution) to the ol.source.Cluster.prototype.loadFeatures function to force loading.