int executorsWithMetrics = 0;
for (TopologySummary ts: summary.get_topologies()) {
String id = ts.get_id();
TopologyInfo info = client.getTopologyInfo(id);
for (ExecutorSummary es: info.get_executors()) {
ExecutorStats stats = es.get_stats();
totalExecutors++;
if (stats != null) {
Map<String,Map<String,Long>> transferred = stats.get_transferred();
if ( transferred != null) {
Map<String, Long> e2 = transferred.get(":all-time");
if (e2 != null) {
executorsWithMetrics++;
//The SOL messages are always on the default stream, so just count those