Merge branch 'branch-0.4.0' into 'branch-0.4.0'

MS-458 fix bug for keep building index for one file when no gpu resource

See merge request megasearch/milvus!480

Former-commit-id: 6454851f6ccedf216e827105a51306af5e430c3f

cpp/CHANGELOG.md

@@ -17,8 +17,9 @@ Please mark all change in change log and use the ticket from JIRA.
 - MS-430 - Search no result if index created with FLAT
 - MS-443 - Create index hang again
 - MS-436 - Delete vectors failed if index created with index_type: IVF_FLAT/IVF_SQ8
-- MS-450 - server hang after run stop_server.sh
 - MS-449 - Add vectors twice success, once with ids, the other no ids
+- MS-450 - server hang after run stop_server.sh
+- MS-458 - Keep building index for one file when no gpu resource
 - MS-461 - Mysql meta unittest failed
 - MS-462 - Run milvus server twices, should display error
 - MS-463 - Search timeout

cpp/src/db/DBImpl.cpp

@@ -522,7 +522,6 @@ void DBImpl::BackgroundCompaction(std::set<std::string> table_ids) {
         status = BackgroundMergeFiles(table_id);
         if (!status.ok()) {
             ENGINE_LOG_ERROR << "Merge files for table " << table_id << " failed: " << status.ToString();
-            continue;//let other table get chance to merge
         }
 
         if (shutting_down_.load(std::memory_order_acquire)){
@@ -765,7 +764,6 @@ void DBImpl::BackgroundBuildIndex() {
         status = BuildIndex(file);
         if (!status.ok()) {
             ENGINE_LOG_ERROR << "Building index for " << file.id_ << " failed: " << status.ToString();
-            return;
         }
 
         if (shutting_down_.load(std::memory_order_acquire)){