Modifications to throughput capacity provisioned at a data store for servicing access requests to the data store may be performed according to cache performance metrics. A cache that services access requests to the data store may be monitored to collected and evaluate cache performance metrics. The cache performance metrics may be evaluated with respect to criteria for triggering different throughput modifications. In response to triggering a throughput modification, the throughput capacity for the data store may be modified according to the triggered throughput modification. In some embodiments, the criteria for detecting throughput modifications may be determined and modified based on cache performance metrics.