test_scheduler core dump

Former-commit-id: 79208b55f7b016bde5100cc7474850160dc72503

CHANGELOG.md

@@ -5,6 +5,8 @@ Please mark all change in change log and use the ticket from JIRA.
 # Milvus 0.5.1 (TODO)
 
 ## Bug
+- \#104 - test_scheduler core dump
+
 ## Improvement
 - \#64 - Improvement dump function in scheduler
 - \#80 - Print version information into log during server start

core/src/scheduler/resource/Resource.h

@@ -119,6 +119,9 @@ class Resource : public Node, public std::enable_shared_from_this<Resource> {
     // TODO(wxyu): need double ?
     inline uint64_t
     TaskAvgCost() const {
+        if (total_task_ == 0) {
+            return 0;
+        }
         return total_cost_ / total_task_;
     }