diff --git a/core/src/db/snapshot/SnapshotHolder.cpp b/core/src/db/snapshot/SnapshotHolder.cpp
index 6a9bfebbd1..70c70fb85c 100644
--- a/core/src/db/snapshot/SnapshotHolder.cpp
+++ b/core/src/db/snapshot/SnapshotHolder.cpp
@@ -206,7 +206,7 @@ SnapshotHolder::Add(StorePtr store, ID_TYPE id) {
         LOG_SERVER_DEBUG_ << "SSLoad CCID=" << id << " for CID=" << ss->GetCollectionId() << " CNAME=" << ss->GetName();
         active_[id] = ss;
         IDS_TYPE to_eject;
-        if (policy_->ShouldEject(active_, to_eject, false) == 0) {
+        if (policy_->ShouldEject(active_, to_eject, true) == 0) {
             return status;
         }
         for (auto& id : to_eject) {
diff --git a/core/src/db/snapshot/SnapshotPolicy.cpp b/core/src/db/snapshot/SnapshotPolicy.cpp
index 43d5c75459..5e11fc8a86 100644
--- a/core/src/db/snapshot/SnapshotPolicy.cpp
+++ b/core/src/db/snapshot/SnapshotPolicy.cpp
@@ -56,7 +56,7 @@ SnapshotDurationPolicy::ShouldEject(const MapT& ids, IDS_TYPE& to_eject, bool al
     auto now_us = GetMicroSecTimeStamp();
     auto max_id = ids.rbegin()->first;
     for (auto& [id, ss] : ids) {
-        if ((now_us - ss->GetCollectionCommit()->GetCreatedTime() < us_) && (id != max_id)) {
+        if ((now_us - ss->GetCollectionCommit()->GetCreatedTime() > us_) && (!alive || id != max_id)) {
             to_eject.push_back(id);
         }
     }
diff --git a/core/src/db/snapshot/Snapshots.cpp b/core/src/db/snapshot/Snapshots.cpp
index 2319089073..97a5cf33d8 100644
--- a/core/src/db/snapshot/Snapshots.cpp
+++ b/core/src/db/snapshot/Snapshots.cpp
@@ -25,7 +25,7 @@
 
 namespace milvus::engine::snapshot {
 
-static constexpr int DEFAULT_READER_TIMER_INTERVAL_US = 60 * 1000;
+static constexpr int DEFAULT_READER_TIMER_INTERVAL_US = 100 * 1000;
 static constexpr int DEFAULT_WRITER_TIMER_INTERVAL_US = 2000 * 1000;
 
 Status
@@ -345,10 +345,10 @@ Snapshots::OnReaderTimer(const boost::system::error_code& ec) {
         holders_.erase(cid);
     }
     auto exe_time =
-        std::chrono::duration_cast<std::chrono::milliseconds>(std::chrono::high_resolution_clock::now() - start)
+        std::chrono::duration_cast<std::chrono::microseconds>(std::chrono::high_resolution_clock::now() - start)
             .count();
     if (exe_time > DEFAULT_READER_TIMER_INTERVAL_US) {
-        LOG_ENGINE_WARNING_ << "OnReaderTimer takes too much time: " << exe_time << " ms";
+        LOG_ENGINE_WARNING_ << "OnReaderTimer takes too much time: " << exe_time << " us";
     }
 }