Merge remote-tracking branch 'source/branch-0.3.1-yuncong' into branch-0.3.1-yuncong

Former-commit-id: 012516472249a55514144cba5c2e06c81b567537

cpp/conf/server_config.template

@@ -35,5 +35,5 @@ cache_config:           # cache configure
 
 engine_config:
   nprobe: 10
-  nlist: 16381
-  use_blas_threshold: 10
\ No newline at end of file
+  nlist: 16384
+  use_blas_threshold: 20
\ No newline at end of file

cpp/src/db/DBImpl.cpp

@@ -438,7 +438,7 @@ Status DBImpl::BuildIndex(const std::string& table_id) {
     while (has) {
         ENGINE_LOG_DEBUG << "Non index files detected! Will build index " << times;
         meta_ptr_->UpdateTableFilesToIndex(table_id);
-        StartBuildIndexTask(true);
+        /* StartBuildIndexTask(true); */
         std::this_thread::sleep_for(std::chrono::milliseconds(std::min(10*1000, times*100)));
         meta_ptr_->HasNonIndexFiles(table_id, has);
         times++;