diff --git a/cpp/conf/server_config.template b/cpp/conf/server_config.template
index 43b6f3ba1661dfa1d88c7b96d90e2dabe90a3e71..2dd8daa0f19a04d86b88b2d32b1acb4141cfca41 100644
--- a/cpp/conf/server_config.template
+++ b/cpp/conf/server_config.template
@@ -16,8 +16,8 @@ db_config:
   index_building_threshold: 1024   # index building trigger threshold, default: 1024, unit: MB
   archive_disk_threshold: 0        # triger archive action if storage size exceed this value, 0 means no limit, unit: GB
   archive_days_threshold: 0        # files older than x days will be archived, 0 means no limit, unit: day
-  maximum_memory: 4                # maximum memory allowed, default: 4, unit: GB, should be at least 1 GB.
-                                   # the sum of maximum_memory and cpu_cache_capacity should be less than total memory
+  insert_buffer_size: 4            # maximum insert buffer size allowed, default: 4, unit: GB, should be at least 1 GB.
+                                   # the sum of insert_buffer_size and cpu_cache_capacity should be less than total memory
 
 metric_config:
   is_startup: off      # if monitoring start: on, off
diff --git a/cpp/src/db/NewMemManager.cpp b/cpp/src/db/NewMemManager.cpp
index 405d3771fd4009d0f347c5977625c1724db82a24..c7291354ad2c133ad81ac88999377b0e1d7efebf 100644
--- a/cpp/src/db/NewMemManager.cpp
+++ b/cpp/src/db/NewMemManager.cpp
@@ -25,7 +25,7 @@ Status NewMemManager::InsertVectors(const std::string &table_id_,
                                     const float *vectors_,
                                     IDNumbers &vector_ids_) {
 
-    while (GetCurrentMem() > options_.maximum_memory) {
+    while (GetCurrentMem() > options_.insert_buffer_size) {
         std::this_thread::sleep_for(std::chrono::milliseconds(1));
     }
 
diff --git a/cpp/src/db/Options.h b/cpp/src/db/Options.h
index a12afbfd80d77caaa5e2b4a07158257312480fc3..efc5ee3604f0613277494dabdd0fb0d7063b3053 100644
--- a/cpp/src/db/Options.h
+++ b/cpp/src/db/Options.h
@@ -63,7 +63,7 @@ struct Options {
     size_t  index_trigger_size = ONE_GB;            //unit: byte
     DBMetaOptions meta;
     int mode = MODE::SINGLE;
-    size_t maximum_memory = 4 * ONE_GB;
+    size_t insert_buffer_size = 4 * ONE_GB;
 }; // Options
 
 
diff --git a/cpp/src/server/DBWrapper.cpp b/cpp/src/server/DBWrapper.cpp
index c01e1acda3abee8bd4c34ae9486cbf1cddc3e214..6c6717657150e711b0462d5e8173ddc3dee5dc30 100644
--- a/cpp/src/server/DBWrapper.cpp
+++ b/cpp/src/server/DBWrapper.cpp
@@ -28,12 +28,12 @@ DBWrapper::DBWrapper() {
     if(index_size > 0) {//ensure larger than zero, unit is MB
         opt.index_trigger_size = (size_t)index_size * engine::ONE_MB;
     }
-    int64_t maximum_memory = config.GetInt64Value(CONFIG_MAXMIMUM_MEMORY);
-    if (maximum_memory > 1.0) {
-        opt.maximum_memory = maximum_memory * engine::ONE_GB;
+    int64_t insert_buffer_size = config.GetInt64Value(CONFIG_DB_INSERT_BUFFER_SIZE, 4);
+    if (insert_buffer_size >= 1) {
+        opt.insert_buffer_size = insert_buffer_size * engine::ONE_GB;
     }
-    else if (maximum_memory != 0) { //if maximum_memory = 0, set it to default
-        std::cout << "ERROR: maximum_memory should be at least 1 GB" << std::endl;
+    else {
+        std::cout << "ERROR: insert_buffer_size should be at least 1 GB" << std::endl;
         kill(0, SIGUSR1);
     }
 
diff --git a/cpp/src/server/ServerConfig.h b/cpp/src/server/ServerConfig.h
index d3fb77a8cb9e1911184d794ef74fb5cd5005b7be..bc202adcf625b349b55412e6240d81cdd6d60721 100644
--- a/cpp/src/server/ServerConfig.h
+++ b/cpp/src/server/ServerConfig.h
@@ -27,7 +27,7 @@ static const std::string CONFIG_DB_SLAVE_PATH = "db_slave_path";
 static const std::string CONFIG_DB_INDEX_TRIGGER_SIZE = "index_building_threshold";
 static const std::string CONFIG_DB_ARCHIVE_DISK = "archive_disk_threshold";
 static const std::string CONFIG_DB_ARCHIVE_DAYS = "archive_days_threshold";
-static const std::string CONFIG_MAXMIMUM_MEMORY = "maximum_memory";
+static const std::string CONFIG_DB_INSERT_BUFFER_SIZE = "insert_buffer_size";
 
 static const std::string CONFIG_LOG = "log_config";