add rank id to trace file name (#3525)

Author: Wenzhe Xue

src/ngraph/event_tracing.cpp

@@ -18,6 +18,7 @@
 #include <sstream>
 #include <string>
 
+#include "distributed.hpp"
 #include "event_tracing.hpp"
 #include "nlohmann/json.hpp"
 
@@ -42,7 +43,15 @@ void ngraph::Event::write_trace(const ngraph::Event& event)
         if (!so_initialized)
         {
             // Open the file
-            s_event_log.open("ngraph_event_trace.json", ios_base::trunc);
+            std::string file_name = "ngraph_event_trace.json";
+            if (get_distributed_interface()->get_size() > 1)
+            {
+                auto rank = std::to_string(get_distributed_interface()->get_rank());
+                int num_zero = 3;
+                std::string prefix = std::string(num_zero - rank.length(), '0') + rank + "_";
+                file_name.insert(0, prefix);
+            }
+            s_event_log.open(file_name, ios_base::trunc);
             s_event_log << "[\n";
             so_initialized = true;
         }