According to https://docs.mongodb.org/manual/reference/command/serverStatus/#server-status-cursors, the `serverStatus.cursors` field has been deprecated since 2.6 (in favor of https://docs.mongodb.org/manual/reference/command/serverStatus/#server-status-metrics). It appears to have been removed in 3.2 (based on some PHP driver test failures I've seen), but this is not reflected in the documentation.