Remove redefinition

Former-commit-id: 4dd734c7ebffa9a462c641b0e220a62668651859

cpp/src/server/DBWrapper.cpp

@@ -53,22 +53,6 @@ DBWrapper::DBWrapper() {
         kill(0, SIGUSR1);
     }
 
-    ConfigNode& serverConfig = ServerConfig::GetInstance().GetConfig(CONFIG_SERVER);
-    std::string mode = serverConfig.GetValue(CONFIG_CLUSTER_MODE, "single");
-    if (mode == "single") {
-        opt.mode = zilliz::milvus::engine::Options::MODE::SINGLE;
-    }
-    else if (mode == "cluster") {
-        opt.mode = zilliz::milvus::engine::Options::MODE::CLUSTER;
-    }
-    else if (mode == "read_only") {
-        opt.mode = zilliz::milvus::engine::Options::MODE::READ_ONLY;
-    }
-    else {
-        std::cout << "ERROR: mode specified in server_config is not one of ['single', 'cluster', 'read_only']" << std::endl;
-        kill(0, SIGUSR1);
-    }
-
     //set archive config
     engine::ArchiveConf::CriteriaT criterial;
     int64_t disk = config.GetInt64Value(CONFIG_DB_ARCHIVE_DISK, 0);