diff --git a/cpp/src/db/DBImpl.cpp b/cpp/src/db/DBImpl.cpp
index 17280b37d3820168412749211d75ec0a5901bec7..e39942d35d776c2ed0b706af75245a9ab7d3d933 100644
--- a/cpp/src/db/DBImpl.cpp
+++ b/cpp/src/db/DBImpl.cpp
@@ -13,6 +13,7 @@
 #include "scheduler/context/SearchContext.h"
 #include "scheduler/context/DeleteContext.h"
 #include "utils/TimeRecorder.h"
+#include "MetaConsts.h"
 
 #include <assert.h>
 #include <chrono>
@@ -595,7 +596,12 @@ void DBImpl::BackgroundCompaction(std::set<std::string> table_ids) {
     }
 
     meta_ptr_->Archive();
-    meta_ptr_->CleanUpFilesWithTTL(1);
+
+    int ttl = 1;
+    if (options_.mode == "cluster") {
+        ttl = meta::D_SEC;
+    }
+    meta_ptr_->CleanUpFilesWithTTL(ttl);
 }
 
 void DBImpl::StartBuildIndexTask() {
diff --git a/cpp/src/db/Factories.cpp b/cpp/src/db/Factories.cpp
index fd005d1ff560bcd0e9bd7cb27c9406abdd0590a9..a6998d10dc02670d236f3fde90507cb298db42e6 100644
--- a/cpp/src/db/Factories.cpp
+++ b/cpp/src/db/Factories.cpp
@@ -81,9 +81,11 @@ std::shared_ptr<meta::Meta> DBMetaImplFactory::Build(const DBMetaOptions& metaOp
         std::string dialect = pieces_match[1].str();
         std::transform(dialect.begin(), dialect.end(), dialect.begin(), ::tolower);
         if (dialect.find("mysql") != std::string::npos) {
+            ENGINE_LOG_DEBUG << "Using MySQL";
             return std::make_shared<meta::MySQLMetaImpl>(meta::MySQLMetaImpl(metaOptions));
         }
         else if (dialect.find("sqlite") != std::string::npos) {
+            ENGINE_LOG_DEBUG << "Using SQLite";
             return std::make_shared<meta::DBMetaImpl>(meta::DBMetaImpl(metaOptions));
         }
         else {
diff --git a/cpp/src/db/Options.h b/cpp/src/db/Options.h
index ddb7d1bff5eb51740517412bf267c30838f8770e..039134ebaa21c8536782046d73e794a2ec9b38b9 100644
--- a/cpp/src/db/Options.h
+++ b/cpp/src/db/Options.h
@@ -47,6 +47,7 @@ struct Options {
     uint16_t  merge_trigger_number = 2;
     size_t  index_trigger_size = ONE_GB;            //unit: byte
     DBMetaOptions meta;
+    std::string mode;
 }; // Options
 
 
diff --git a/cpp/src/server/DBWrapper.cpp b/cpp/src/server/DBWrapper.cpp
index 0721de1325605928ce6943fabac476ba26c1615e..c38c5d8843345ac54b8f84997fd33b8649106721 100644
--- a/cpp/src/server/DBWrapper.cpp
+++ b/cpp/src/server/DBWrapper.cpp
@@ -23,6 +23,7 @@ DBWrapper::DBWrapper() {
     if(index_size > 0) {//ensure larger than zero, unit is MB
         opt.index_trigger_size = (size_t)index_size * engine::ONE_MB;
     }
+    opt.mode = config.GetValue(CONFIG_CLUSTER_MODE, "single");
 
     CommonUtil::CreateDirectory(opt.meta.path);
 
diff --git a/cpp/src/server/ServerConfig.h b/cpp/src/server/ServerConfig.h
index dd7c9d2966046656859617a4099c449cbdc9776d..aa77b081d78a6da0e6796b0aab5162d2f4866ca4 100644
--- a/cpp/src/server/ServerConfig.h
+++ b/cpp/src/server/ServerConfig.h
@@ -19,6 +19,7 @@ static const std::string CONFIG_SERVER_ADDRESS = "address";
 static const std::string CONFIG_SERVER_PORT = "port";
 static const std::string CONFIG_SERVER_PROTOCOL = "transfer_protocol";
 static const std::string CONFIG_SERVER_MODE = "server_mode";
+static const std::string CONFIG_CLUSTER_MODE = "mode";
 
 static const std::string CONFIG_DB = "db_config";
 static const std::string CONFIG_DB_URL = "db_backend_url";