add more error handling

Former-commit-id: 21d14f9541d81e2a30a59c4501835d5f549c5360

cpp/src/server/DBWrapper.cpp

@@ -40,12 +40,16 @@ DBWrapper::DBWrapper() {
     opt.meta.archive_conf.SetCriterias(criterial);
 
     //create db root folder
-    CommonUtil::CreateDirectory(opt.meta.path);
+    ServerError err = CommonUtil::CreateDirectory(opt.meta.path);
+    if(err != SERVER_SUCCESS) {
+        std::cout << "ERROR! Failed to create database root path: " << opt.meta.path << std::endl;
+        kill(0, SIGUSR1);
+    }
 
     zilliz::milvus::engine::DB::Open(opt, &db_);
     if(db_ == nullptr) {
-        SERVER_LOG_ERROR << "Failed to open db. Provided database uri = " << opt.meta.backend_uri;
-        throw ServerException(SERVER_NULL_POINTER, "Failed to open db");
+        std::cout << "ERROR! Failed to open database" << std::endl;
+        kill(0, SIGUSR1);
     }
 }
 

cpp/src/server/MilvusServer.cpp

@@ -24,6 +24,7 @@
 #include <thrift/concurrency/PosixThreadFactory.h>
 
 #include <thread>
+#include <iostream>
 
 namespace zilliz {
 namespace milvus {
@@ -93,7 +94,8 @@ MilvusServer::StartService() {
             return;
         }
     } catch (apache::thrift::TException& ex) {
-        SERVER_LOG_ERROR << "Server encounter exception: " << ex.what();
+        std::cout << "ERROR! " << ex.what() << std::endl;
+        kill(0, SIGUSR1);
     }
 }