logging build index progress (#2411)

Signed-off-by: Nwxyu <xy.wang@zilliz.com>

CHANGELOG.md

@@ -15,6 +15,7 @@ Please mark all change in change log and use the issue from GitHub
 -   \#2353 Remove log_config from code and scripts
 -   \#2370 Clean compile warning
 -   \#2381 Upgrade FAISS to 1.6.3
+-   \#2410 Logging build index progress
 
 ## Task
 

core/src/db/DBImpl.cpp

@@ -2124,10 +2124,12 @@ DBImpl::BackgroundBuildIndex() {
         }
 
         // step 3: wait build index finished and mark failed files
+        int64_t completed = 0;
         for (auto iter = job2file_map.begin(); iter != job2file_map.end(); ++iter) {
             scheduler::BuildIndexJobPtr job = iter->first;
             meta::SegmentSchema& file_schema = *(iter->second.get());
             job->WaitBuildIndexFinish();
+            LOG_ENGINE_INFO_ << "Build Index Progress: " << ++completed << " of " << job2file_map.size();
             if (!job->GetStatus().ok()) {
                 Status status = job->GetStatus();
                 LOG_ENGINE_ERROR_ << "Building index job " << job->id() << " failed: " << status.ToString();