diff --git a/CHANGELOG.md b/CHANGELOG.md
index fd45cb66e0..d9acff7d93 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -27,7 +27,8 @@ Please mark all change in change log and use the issue from GitHub
 -   \#2228 Fix show partitions failed in http module
 -   \#2231 Use server_config to define hard-delete delay time for segment files
 -   \#2261 Re-define result returned by has_collection if collection in delete state
--   \#2266 Server hang when using multi-clients to query different collections
+-   \#2264 Milvus opened too many files when the metric_config.enable_monitor=true
+-   \#2266 Server hangs when using multi-clients to query different collections
 -   \#2280 has_partition should return true for '_default'
 
 ## Feature
diff --git a/core/src/db/DBImpl.cpp b/core/src/db/DBImpl.cpp
index 53ad1d12c4..03276c2c80 100644
--- a/core/src/db/DBImpl.cpp
+++ b/core/src/db/DBImpl.cpp
@@ -2053,7 +2053,7 @@ DBImpl::BackgroundMerge(std::set<std::string> collection_ids) {
     meta_ptr_->Archive();
 
     {
-        uint64_t timeout = (options_.file_cleanup_timeout_ > 0) ? options_.file_cleanup_timeout_ : 10;
+        uint64_t timeout = (options_.file_cleanup_timeout_ >= 0) ? options_.file_cleanup_timeout_ : 10;
         uint64_t ttl = timeout * meta::SECOND;  // default: file will be hard-deleted few seconds after soft-deleted
         meta_ptr_->CleanUpFilesWithTTL(ttl);
     }
diff --git a/core/src/metrics/SystemInfo.cpp b/core/src/metrics/SystemInfo.cpp
index 711c7cb885..c789edb797 100644
--- a/core/src/metrics/SystemInfo.cpp
+++ b/core/src/metrics/SystemInfo.cpp
@@ -321,6 +321,7 @@ SystemInfo::CPUTemperature() {
                     if (fscanf(file, "%f", &temp) != -1) {
                         result.push_back(temp / 1000);
                     }
+                    fclose(file);
                 }
             }
         }
diff --git a/core/unittest/db/utils.cpp b/core/unittest/db/utils.cpp
index f78fead163..a33027cdeb 100644
--- a/core/unittest/db/utils.cpp
+++ b/core/unittest/db/utils.cpp
@@ -195,8 +195,8 @@ DBTest::SetUp() {
 #endif
     res_mgr->Start();
     milvus::scheduler::SchedInst::GetInstance()->Start();
-
     milvus::scheduler::JobMgrInst::GetInstance()->Start();
+    milvus::scheduler::CPUBuilderInst::GetInstance()->Start();
 
     auto options = GetOptions();
     options.insert_cache_immediately_ = true;
@@ -215,6 +215,7 @@ DBTest::TearDown() {
 
     milvus::scheduler::JobMgrInst::GetInstance()->Stop();
     milvus::scheduler::SchedInst::GetInstance()->Stop();
+    milvus::scheduler::CPUBuilderInst::GetInstance()->Stop();
     milvus::scheduler::ResMgrInst::GetInstance()->Stop();
     milvus::scheduler::ResMgrInst::GetInstance()->Clear();