#2378 (#2388)

* return partition lsn

Signed-off-by: yhmo <yihua.mo@zilliz.com>

* fix wal lsn

Signed-off-by: shengjun.li <shengjun.li@zilliz.com>

* fix wal issue

Signed-off-by: yhmo <yihua.mo@zilliz.com>

* changelog

Signed-off-by: yhmo <yihua.mo@zilliz.com>

* typo

Signed-off-by: yhmo <yihua.mo@zilliz.com>

* all collection include partition

Signed-off-by: yhmo <yihua.mo@zilliz.com>

* fix build error

Signed-off-by: yhmo <yihua.mo@zilliz.com>

* fix flush

Signed-off-by: shengjun.li <shengjun.li@zilliz.com>

Co-authored-by: shengjun.li <shengjun.li@zilliz.com>

CHANGELOG.md

@@ -4,6 +4,7 @@ Please mark all change in change log and use the issue from GitHub
 # Milvus 0.10.0 (TBD)
 
 ## Bug
+-   \#2378 Duplicate data after server restart
 
 ## Feature
 -   \#2363 Update branch version

core/src/db/DBImpl.cpp

@@ -487,7 +487,11 @@ DBImpl::CreatePartition(const std::string& collection_id, const std::string& par
     }
 
     uint64_t lsn = 0;
-    meta_ptr_->GetCollectionFlushLSN(collection_id, lsn);
+    if (options_.wal_enable_) {
+        lsn = wal_mgr_->CreatePartition(collection_id, partition_tag);
+    } else {
+        meta_ptr_->GetCollectionFlushLSN(collection_id, lsn);
+    }
     return meta_ptr_->CreatePartition(collection_id, partition_name, partition_tag, lsn);
 }
 
@@ -545,6 +549,10 @@ DBImpl::DropPartitionByTag(const std::string& collection_id, const std::string&
         return status;
     }
 
+    if (options_.wal_enable_) {
+        wal_mgr_->DropPartition(collection_id, partition_tag);
+    }
+
     return DropPartition(partition_name);
 }
 
@@ -891,7 +899,7 @@ DBImpl::Flush(const std::string& collection_id) {
             swn_wal_.Notify();
             flush_req_swn_.Wait();
         }
-
+        StartMergeTask();
     } else {
         LOG_ENGINE_DEBUG_ << "MemTable flush";
         InternalFlush(collection_id);
@@ -918,6 +926,7 @@ DBImpl::Flush() {
             swn_wal_.Notify();
             flush_req_swn_.Wait();
         }
+        StartMergeTask();
     } else {
         LOG_ENGINE_DEBUG_ << "MemTable flush";
         InternalFlush();
@@ -1421,7 +1430,9 @@ DBImpl::DropIndex(const std::string& collection_id) {
     }
 
     LOG_ENGINE_DEBUG_ << "Drop index for collection: " << collection_id;
-    return DropCollectionIndexRecursively(collection_id);
+    auto status = DropCollectionIndexRecursively(collection_id);
+    StartMergeTask();  // merge small files after drop index
+    return status;
 }
 
 Status
@@ -2407,30 +2418,39 @@ Status
 DBImpl::ExecWalRecord(const wal::MXLogRecord& record) {
     fiu_return_on("DBImpl.ExexWalRecord.return", Status(););
 
-    auto collections_flushed = [&](const std::set<std::string>& collection_ids) -> uint64_t {
-        if (collection_ids.empty()) {
-            return 0;
-        }
-
+    auto collections_flushed = [&](const std::string collection_id,
+                                   const std::set<std::string>& target_collection_names) -> uint64_t {
         uint64_t max_lsn = 0;
         if (options_.wal_enable_) {
-            for (auto& collection : collection_ids) {
-                uint64_t lsn = 0;
+            uint64_t lsn = 0;
+            for (auto& collection : target_collection_names) {
                 meta_ptr_->GetCollectionFlushLSN(collection, lsn);
-                wal_mgr_->CollectionFlushed(collection, lsn);
                 if (lsn > max_lsn) {
                     max_lsn = lsn;
                 }
             }
+            wal_mgr_->CollectionFlushed(collection_id, lsn);
         }
 
         std::lock_guard<std::mutex> lck(merge_result_mutex_);
-        for (auto& collection : collection_ids) {
+        for (auto& collection : target_collection_names) {
             merge_collection_ids_.insert(collection);
         }
         return max_lsn;
     };
 
+    auto partition_flushed = [&](const std::string& collection_id, const std::string& partition,
+                                 const std::string& target_collection_name) {
+        if (options_.wal_enable_) {
+            uint64_t lsn = 0;
+            meta_ptr_->GetCollectionFlushLSN(target_collection_name, lsn);
+            wal_mgr_->PartitionFlushed(collection_id, partition, lsn);
+        }
+
+        std::lock_guard<std::mutex> lck(merge_result_mutex_);
+        merge_collection_ids_.insert(target_collection_name);
+    };
+
     Status status;
 
     switch (record.type) {
@@ -2447,7 +2467,9 @@ DBImpl::ExecWalRecord(const wal::MXLogRecord& record) {
                                               (record.data_size / record.length / sizeof(float)),
                                               (const float*)record.data, record.attr_nbytes, record.attr_data_size,
                                               record.attr_data, record.lsn, flushed_collections);
-            collections_flushed(flushed_collections);
+            if (!flushed_collections.empty()) {
+                partition_flushed(record.collection_id, record.partition_tag, target_collection_name);
+            }
 
             milvus::server::CollectInsertMetrics metrics(record.length, status);
             break;
@@ -2465,7 +2487,9 @@ DBImpl::ExecWalRecord(const wal::MXLogRecord& record) {
                                              (record.data_size / record.length / sizeof(uint8_t)),
                                              (const u_int8_t*)record.data, record.lsn, flushed_collections);
             // even though !status.ok, run
-            collections_flushed(flushed_collections);
+            if (!flushed_collections.empty()) {
+                partition_flushed(record.collection_id, record.partition_tag, target_collection_name);
+            }
 
             // metrics
             milvus::server::CollectInsertMetrics metrics(record.length, status);
@@ -2485,7 +2509,9 @@ DBImpl::ExecWalRecord(const wal::MXLogRecord& record) {
                                              (record.data_size / record.length / sizeof(float)),
                                              (const float*)record.data, record.lsn, flushed_collections);
             // even though !status.ok, run
-            collections_flushed(flushed_collections);
+            if (!flushed_collections.empty()) {
+                partition_flushed(record.collection_id, record.partition_tag, target_collection_name);
+            }
 
             // metrics
             milvus::server::CollectInsertMetrics metrics(record.length, status);
@@ -2548,7 +2574,7 @@ DBImpl::ExecWalRecord(const wal::MXLogRecord& record) {
                     flushed_collections.insert(collection_id);
                 }
 
-                collections_flushed(flushed_collections);
+                collections_flushed(record.collection_id, flushed_collections);
 
             } else {
                 // flush all collections
@@ -2558,7 +2584,7 @@ DBImpl::ExecWalRecord(const wal::MXLogRecord& record) {
                     status = mem_mgr_->Flush(collection_ids);
                 }
 
-                uint64_t lsn = collections_flushed(collection_ids);
+                uint64_t lsn = collections_flushed("", collection_ids);
                 if (options_.wal_enable_) {
                     wal_mgr_->RemoveOldFiles(lsn);
                 }

core/src/db/meta/Meta.h

@@ -59,7 +59,7 @@ class Meta {
     HasCollection(const std::string& collection_id, bool& has_or_not, bool is_root = false) = 0;
 
     virtual Status
-    AllCollections(std::vector<CollectionSchema>& table_schema_array) = 0;
+    AllCollections(std::vector<CollectionSchema>& table_schema_array, bool is_root = false) = 0;
 
     virtual Status
     UpdateCollectionFlag(const std::string& collection_id, int64_t flag) = 0;

core/src/db/meta/MySQLMetaImpl.cpp

@@ -582,7 +582,7 @@ MySQLMetaImpl::HasCollection(const std::string& collection_id, bool& has_or_not,
 }
 
 Status
-MySQLMetaImpl::AllCollections(std::vector<CollectionSchema>& collection_schema_array) {
+MySQLMetaImpl::AllCollections(std::vector<CollectionSchema>& collection_schema_array, bool is_root) {
     try {
         server::MetricCollector metric;
         mysqlpp::StoreQueryResult res;
@@ -599,8 +599,12 @@ MySQLMetaImpl::AllCollections(std::vector<CollectionSchema>& collection_schema_a
             mysqlpp::Query statement = connectionPtr->query();
             statement << "SELECT id, table_id, dimension, engine_type, index_params, index_file_size, metric_type"
                       << " ,owner_table, partition_tag, version, flush_lsn"
-                      << " FROM " << META_TABLES << " WHERE state <> " << std::to_string(CollectionSchema::TO_DELETE)
-                      << " AND owner_table = \"\";";
+                      << " FROM " << META_TABLES << " WHERE state <> " << std::to_string(CollectionSchema::TO_DELETE);
+            if (is_root) {
+                statement << " AND owner_table = \"\";";
+            } else {
+                statement << ";";
+            }
 
             LOG_ENGINE_DEBUG_ << "AllCollections: " << statement.str();
 
@@ -1535,8 +1539,8 @@ MySQLMetaImpl::ShowPartitions(const std::string& collection_id,
 
             mysqlpp::Query statement = connectionPtr->query();
             statement << "SELECT table_id, id, state, dimension, created_on, flag, index_file_size,"
-                      << " engine_type, index_params, metric_type, partition_tag, version FROM " << META_TABLES
-                      << " WHERE owner_table = " << mysqlpp::quote << collection_id << " AND state <> "
+                      << " engine_type, index_params, metric_type, partition_tag, version, flush_lsn FROM "
+                      << META_TABLES << " WHERE owner_table = " << mysqlpp::quote << collection_id << " AND state <> "
                       << std::to_string(CollectionSchema::TO_DELETE) << ";";
 
             LOG_ENGINE_DEBUG_ << "ShowPartitions: " << statement.str();
@@ -1559,6 +1563,7 @@ MySQLMetaImpl::ShowPartitions(const std::string& collection_id,
             partition_schema.owner_collection_ = collection_id;
             resRow["partition_tag"].to_string(partition_schema.partition_tag_);
             resRow["version"].to_string(partition_schema.version_);
+            partition_schema.flush_lsn_ = resRow["flush_lsn"];
 
             partition_schema_array.emplace_back(partition_schema);
         }
@@ -2755,6 +2760,7 @@ MySQLMetaImpl::SetGlobalLastLSN(uint64_t lsn) {
             }
 
             bool first_create = false;
+            uint64_t last_lsn = 0;
             {
                 mysqlpp::StoreQueryResult res;
                 mysqlpp::Query statement = connectionPtr->query();
@@ -2762,6 +2768,8 @@ MySQLMetaImpl::SetGlobalLastLSN(uint64_t lsn) {
                 res = statement.store();
                 if (res.num_rows() == 0) {
                     first_create = true;
+                } else {
+                    last_lsn = res[0]["global_lsn"];
                 }
             }
 
@@ -2773,7 +2781,7 @@ MySQLMetaImpl::SetGlobalLastLSN(uint64_t lsn) {
                 if (!statement.exec()) {
                     return HandleException("QUERY ERROR WHEN SET GLOBAL LSN", statement.error());
                 }
-            } else {
+            } else if (lsn > last_lsn) {
                 mysqlpp::Query statement = connectionPtr->query();
                 statement << "UPDATE " << META_ENVIRONMENT << " SET global_lsn = " << lsn << ";";
                 LOG_ENGINE_DEBUG_ << "SetGlobalLastLSN: " << statement.str();
@@ -2783,8 +2791,6 @@ MySQLMetaImpl::SetGlobalLastLSN(uint64_t lsn) {
                 }
             }
         }  // Scoped Connection
-
-        LOG_ENGINE_DEBUG_ << "Successfully update global_lsn: " << lsn;
     } catch (std::exception& e) {
         return HandleException("Failed to set global lsn", e.what());
     }

core/src/db/meta/MySQLMetaImpl.h

@@ -42,7 +42,7 @@ class MySQLMetaImpl : public Meta {
     HasCollection(const std::string& collection_id, bool& has_or_not, bool is_root = false) override;
 
     Status
-    AllCollections(std::vector<CollectionSchema>& collection_schema_array) override;
+    AllCollections(std::vector<CollectionSchema>& collection_schema_array, bool is_root = false) override;
 
     Status
     DropCollection(const std::string& collection_id) override;

core/src/db/meta/SqliteMetaImpl.cpp

@@ -309,29 +309,37 @@ SqliteMetaImpl::HasCollection(const std::string& collection_id, bool& has_or_not
 }
 
 Status
-SqliteMetaImpl::AllCollections(std::vector<CollectionSchema>& collection_schema_array) {
+SqliteMetaImpl::AllCollections(std::vector<CollectionSchema>& collection_schema_array, bool is_root) {
     try {
         fiu_do_on("SqliteMetaImpl.AllCollections.throw_exception", throw std::exception());
         server::MetricCollector metric;
 
         // multi-threads call sqlite update may get exception('bad logic', etc), so we add a lock here
         std::lock_guard<std::mutex> meta_lock(meta_mutex_);
-        auto selected = ConnectorPtr->select(
-            columns(&CollectionSchema::id_,
-                    &CollectionSchema::collection_id_,
-                    &CollectionSchema::dimension_,
-                    &CollectionSchema::created_on_,
-                    &CollectionSchema::flag_,
-                    &CollectionSchema::index_file_size_,
-                    &CollectionSchema::engine_type_,
-                    &CollectionSchema::index_params_,
-                    &CollectionSchema::metric_type_,
-                    &CollectionSchema::owner_collection_,
-                    &CollectionSchema::partition_tag_,
-                    &CollectionSchema::version_,
-                    &CollectionSchema::flush_lsn_),
-            where(c(&CollectionSchema::state_) != (int)CollectionSchema::TO_DELETE
-                  and c(&CollectionSchema::owner_collection_) == ""));
+        auto select_columns = columns(&CollectionSchema::id_,
+                                      &CollectionSchema::collection_id_,
+                                      &CollectionSchema::dimension_,
+                                      &CollectionSchema::created_on_,
+                                      &CollectionSchema::flag_,
+                                      &CollectionSchema::index_file_size_,
+                                      &CollectionSchema::engine_type_,
+                                      &CollectionSchema::index_params_,
+                                      &CollectionSchema::metric_type_,
+                                      &CollectionSchema::owner_collection_,
+                                      &CollectionSchema::partition_tag_,
+                                      &CollectionSchema::version_,
+                                      &CollectionSchema::flush_lsn_);
+        decltype(ConnectorPtr->select(select_columns)) selected;
+
+        if (is_root) {
+            selected = ConnectorPtr->select(select_columns,
+                                            where(c(&CollectionSchema::state_) != (int)CollectionSchema::TO_DELETE
+                                                  and c(&CollectionSchema::owner_collection_) == ""));
+        } else {
+            selected = ConnectorPtr->select(select_columns,
+                                            where(c(&CollectionSchema::state_) != (int)CollectionSchema::TO_DELETE));
+        }
+
         for (auto& collection : selected) {
             CollectionSchema schema;
             schema.id_ = std::get<0>(collection);
@@ -992,7 +1000,8 @@ SqliteMetaImpl::ShowPartitions(const std::string& collection_id,
                     &CollectionSchema::metric_type_,
                     &CollectionSchema::partition_tag_,
                     &CollectionSchema::version_,
-                    &CollectionSchema::collection_id_),
+                    &CollectionSchema::collection_id_,
+                    &CollectionSchema::flush_lsn_),
             where(c(&CollectionSchema::owner_collection_) == collection_id and
                   c(&CollectionSchema::state_) != (int)CollectionSchema::TO_DELETE));
 
@@ -1011,6 +1020,7 @@ SqliteMetaImpl::ShowPartitions(const std::string& collection_id,
             partition_schema.partition_tag_ = std::get<9>(partitions[i]);
             partition_schema.version_ = std::get<10>(partitions[i]);
             partition_schema.collection_id_ = std::get<11>(partitions[i]);
+            partition_schema.flush_lsn_ = std::get<12>(partitions[i]);
             partition_schema_array.emplace_back(partition_schema);
         }
     } catch (std::exception& e) {
@@ -1939,7 +1949,7 @@ SqliteMetaImpl::SetGlobalLastLSN(uint64_t lsn) {
             ConnectorPtr->insert(env);
         } else {
             uint64_t last_lsn = std::get<0>(selected[0]);
-            if (lsn == last_lsn) {
+            if (lsn <= last_lsn) {
                 return Status::OK();
             }
 

core/src/db/meta/SqliteMetaImpl.h

@@ -44,7 +44,7 @@ class SqliteMetaImpl : public Meta {
     HasCollection(const std::string& collection_id, bool& has_or_not, bool is_root = false) override;
 
     Status
-    AllCollections(std::vector<CollectionSchema>& collection_schema_array) override;
+    AllCollections(std::vector<CollectionSchema>& collection_schema_array, bool is_root = false) override;
 
     Status
     DropCollection(const std::string& collection_id) override;

core/src/db/wal/WalManager.cpp

@@ -62,35 +62,55 @@ WalManager::Init(const meta::MetaPtr& meta) {
     if (meta != nullptr) {
         meta->GetGlobalLastLSN(recovery_start);
 
-        std::vector<meta::CollectionSchema> table_schema_array;
-        auto status = meta->AllCollections(table_schema_array);
+        std::vector<meta::CollectionSchema> collention_schema_array;
+        auto status = meta->AllCollections(collention_schema_array);
         if (!status.ok()) {
             return WAL_META_ERROR;
         }
 
-        if (!table_schema_array.empty()) {
-            // get min and max flushed lsn
-            uint64_t min_flused_lsn = table_schema_array[0].flush_lsn_;
-            uint64_t max_flused_lsn = table_schema_array[0].flush_lsn_;
-            for (size_t i = 1; i < table_schema_array.size(); i++) {
-                if (min_flused_lsn > table_schema_array[i].flush_lsn_) {
-                    min_flused_lsn = table_schema_array[i].flush_lsn_;
-                } else if (max_flused_lsn < table_schema_array[i].flush_lsn_) {
-                    max_flused_lsn = table_schema_array[i].flush_lsn_;
+        if (!collention_schema_array.empty()) {
+            u_int64_t min_flushed_lsn = ~(u_int64_t)0;
+            u_int64_t max_flushed_lsn = 0;
+            auto update_limit_lsn = [&](u_int64_t lsn) {
+                if (min_flushed_lsn > lsn) {
+                    min_flushed_lsn = lsn;
+                }
+                if (max_flushed_lsn < lsn) {
+                    max_flushed_lsn = lsn;
+                }
+            };
+
+            for (auto& col_schema : collention_schema_array) {
+                auto& collection = collections_[col_schema.collection_id_];
+                auto& default_part = collection[""];
+                default_part.flush_lsn = col_schema.flush_lsn_;
+                update_limit_lsn(default_part.flush_lsn);
+
+                std::vector<meta::CollectionSchema> partition_schema_array;
+                status = meta->ShowPartitions(col_schema.collection_id_, partition_schema_array);
+                if (!status.ok()) {
+                    return WAL_META_ERROR;
+                }
+                for (auto& par_schema : partition_schema_array) {
+                    auto& partition = collection[par_schema.partition_tag_];
+                    partition.flush_lsn = par_schema.flush_lsn_;
+                    update_limit_lsn(partition.flush_lsn);
                 }
             }
-            if (applied_lsn < max_flused_lsn) {
+
+            if (applied_lsn < max_flushed_lsn) {
                 // a new WAL folder?
-                applied_lsn = max_flused_lsn;
+                applied_lsn = max_flushed_lsn;
             }
-            if (recovery_start < min_flused_lsn) {
+            if (recovery_start < min_flushed_lsn) {
                 // not flush all yet
-                recovery_start = min_flused_lsn;
+                recovery_start = min_flushed_lsn;
             }
 
-            for (auto& schema : table_schema_array) {
-                TableLsn tb_lsn = {schema.flush_lsn_, applied_lsn};
-                tables_[schema.collection_id_] = tb_lsn;
+            for (auto& col : collections_) {
+                for (auto& part : col.second) {
+                    part.second.wal_lsn = applied_lsn;
+                }
             }
         }
     }
@@ -141,9 +161,10 @@ WalManager::GetNextRecovery(MXLogRecord& record) {
 
         // background thread has not started.
         // so, needn't lock here.
-        auto it = tables_.find(record.collection_id);
-        if (it != tables_.end()) {
-            if (it->second.flush_lsn < record.lsn) {
+        auto it_col = collections_.find(record.collection_id);
+        if (it_col != collections_.end()) {
+            auto it_part = it_col->second.find(record.partition_tag);
+            if (it_part->second.flush_lsn < record.lsn) {
                 break;
             }
         }
@@ -179,9 +200,10 @@ WalManager::GetNextEntityRecovery(milvus::engine::wal::MXLogRecord& record) {
 
         // background thread has not started.
         // so, needn't lock here.
-        auto it = tables_.find(record.collection_id);
-        if (it != tables_.end()) {
-            if (it->second.flush_lsn < record.lsn) {
+        auto it_col = collections_.find(record.collection_id);
+        if (it_col != collections_.end()) {
+            auto it_part = it_col->second.find(record.partition_tag);
+            if (it_part->second.flush_lsn < record.lsn) {
                 break;
             }
         }
@@ -229,9 +251,10 @@ WalManager::GetNextRecord(MXLogRecord& record) {
         }
 
         std::lock_guard<std::mutex> lck(mutex_);
-        auto it = tables_.find(record.collection_id);
-        if (it != tables_.end()) {
-            if (it->second.flush_lsn < record.lsn) {
+        auto it_col = collections_.find(record.collection_id);
+        if (it_col != collections_.end()) {
+            auto it_part = it_col->second.find(record.partition_tag);
+            if (it_part->second.flush_lsn < record.lsn) {
                 break;
             }
         }
@@ -275,9 +298,10 @@ WalManager::GetNextEntityRecord(milvus::engine::wal::MXLogRecord& record) {
         }
 
         std::lock_guard<std::mutex> lck(mutex_);
-        auto it = tables_.find(record.collection_id);
-        if (it != tables_.end()) {
-            if (it->second.flush_lsn < record.lsn) {
+        auto it_col = collections_.find(record.collection_id);
+        if (it_col != collections_.end()) {
+            auto it_part = it_col->second.find(record.partition_tag);
+            if (it_part->second.flush_lsn < record.lsn) {
                 break;
             }
         }
@@ -293,7 +317,16 @@ WalManager::CreateCollection(const std::string& collection_id) {
     LOG_WAL_INFO_ << "create collection " << collection_id << " " << last_applied_lsn_;
     std::lock_guard<std::mutex> lck(mutex_);
     uint64_t applied_lsn = last_applied_lsn_;
-    tables_[collection_id] = {applied_lsn, applied_lsn};
+    collections_[collection_id][""] = {applied_lsn, applied_lsn};
+    return applied_lsn;
+}
+
+uint64_t
+WalManager::CreatePartition(const std::string& collection_id, const std::string& partition_tag) {
+    LOG_WAL_INFO_ << "create collection " << collection_id << " " << partition_tag << " " << last_applied_lsn_;
+    std::lock_guard<std::mutex> lck(mutex_);
+    uint64_t applied_lsn = last_applied_lsn_;
+    collections_[collection_id][partition_tag] = {applied_lsn, applied_lsn};
     return applied_lsn;
 }
 
@@ -302,7 +335,7 @@ WalManager::CreateHybridCollection(const std::string& collection_id) {
     LOG_WAL_INFO_ << "create hybrid collection " << collection_id << " " << last_applied_lsn_;
     std::lock_guard<std::mutex> lck(mutex_);
     uint64_t applied_lsn = last_applied_lsn_;
-    tables_[collection_id] = {applied_lsn, applied_lsn};
+    collections_[collection_id][""] = {applied_lsn, applied_lsn};
     return applied_lsn;
 }
 
@@ -310,21 +343,84 @@ void
 WalManager::DropCollection(const std::string& collection_id) {
     LOG_WAL_INFO_ << "drop collection " << collection_id;
     std::lock_guard<std::mutex> lck(mutex_);
-    tables_.erase(collection_id);
+    collections_.erase(collection_id);
+}
+
+void
+WalManager::DropPartition(const std::string& collection_id, const std::string& partition_tag) {
+    LOG_WAL_INFO_ << collection_id << " drop partition " << partition_tag;
+    std::lock_guard<std::mutex> lck(mutex_);
+    auto it = collections_.find(collection_id);
+    if (it != collections_.end()) {
+        it->second.erase(partition_tag);
+    }
 }
 
 void
 WalManager::CollectionFlushed(const std::string& collection_id, uint64_t lsn) {
     std::unique_lock<std::mutex> lck(mutex_);
-    auto it = tables_.find(collection_id);
-    if (it != tables_.end()) {
-        it->second.flush_lsn = lsn;
+    if (collection_id.empty()) {
+        // all collections
+        for (auto& col : collections_) {
+            for (auto& part : col.second) {
+                part.second.flush_lsn = lsn;
+            }
+        }
+
+    } else {
+        // one collection
+        auto it_col = collections_.find(collection_id);
+        if (it_col != collections_.end()) {
+            for (auto& part : it_col->second) {
+                part.second.flush_lsn = lsn;
+            }
+        }
     }
     lck.unlock();
 
     LOG_WAL_INFO_ << collection_id << " is flushed by lsn " << lsn;
 }
 
+void
+WalManager::PartitionFlushed(const std::string& collection_id, const std::string& partition_tag, uint64_t lsn) {
+    std::unique_lock<std::mutex> lck(mutex_);
+    auto it_col = collections_.find(collection_id);
+    if (it_col != collections_.end()) {
+        auto it_part = it_col->second.find(partition_tag);
+        if (it_part != it_col->second.end()) {
+            it_part->second.flush_lsn = lsn;
+        }
+    }
+    lck.unlock();
+
+    LOG_WAL_INFO_ << collection_id << "    " << partition_tag << " is flushed by lsn " << lsn;
+}
+
+void
+WalManager::CollectionUpdated(const std::string& collection_id, uint64_t lsn) {
+    std::unique_lock<std::mutex> lck(mutex_);
+    auto it_col = collections_.find(collection_id);
+    if (it_col != collections_.end()) {
+        for (auto& part : it_col->second) {
+            part.second.wal_lsn = lsn;
+        }
+    }
+    lck.unlock();
+}
+
+void
+WalManager::PartitionUpdated(const std::string& collection_id, const std::string& partition_tag, uint64_t lsn) {
+    std::unique_lock<std::mutex> lck(mutex_);
+    auto it_col = collections_.find(collection_id);
+    if (it_col != collections_.end()) {
+        auto it_part = it_col->second.find(partition_tag);
+        if (it_part != it_col->second.end()) {
+            it_part->second.wal_lsn = lsn;
+        }
+    }
+    lck.unlock();
+}
+
 template <typename T>
 bool
 WalManager::Insert(const std::string& collection_id, const std::string& partition_tag, const IDNumbers& vector_ids,
@@ -380,13 +476,8 @@ WalManager::Insert(const std::string& collection_id, const std::string& partitio
         new_lsn = record.lsn;
     }
 
-    std::unique_lock<std::mutex> lck(mutex_);
     last_applied_lsn_ = new_lsn;
-    auto it = tables_.find(collection_id);
-    if (it != tables_.end()) {
-        it->second.wal_lsn = new_lsn;
-    }
-    lck.unlock();
+    PartitionUpdated(collection_id, partition_tag, new_lsn);
 
     LOG_WAL_INFO_ << LogOut("[%s][%ld]", "insert", 0) << collection_id << " insert in part " << partition_tag
                   << " with lsn " << new_lsn;
@@ -472,13 +563,8 @@ WalManager::InsertEntities(const std::string& collection_id, const std::string&
         new_lsn = record.lsn;
     }
 
-    std::unique_lock<std::mutex> lck(mutex_);
     last_applied_lsn_ = new_lsn;
-    auto it = tables_.find(collection_id);
-    if (it != tables_.end()) {
-        it->second.wal_lsn = new_lsn;
-    }
-    lck.unlock();
+    PartitionUpdated(collection_id, partition_tag, new_lsn);
 
     LOG_WAL_INFO_ << LogOut("[%s][%ld]", "insert", 0) << collection_id << " insert in part " << partition_tag
                   << " with lsn " << new_lsn;
@@ -525,13 +611,8 @@ WalManager::DeleteById(const std::string& collection_id, const IDNumbers& vector
         new_lsn = record.lsn;
     }
 
-    std::unique_lock<std::mutex> lck(mutex_);
     last_applied_lsn_ = new_lsn;
-    auto it = tables_.find(collection_id);
-    if (it != tables_.end()) {
-        it->second.wal_lsn = new_lsn;
-    }
-    lck.unlock();
+    CollectionUpdated(collection_id, new_lsn);
 
     LOG_WAL_INFO_ << collection_id << " delete rows by id, lsn " << new_lsn;
 
@@ -548,19 +629,25 @@ WalManager::Flush(const std::string& collection_id) {
     uint64_t lsn = 0;
     if (collection_id.empty()) {
         // flush all tables
-        for (auto& it : tables_) {
-            if (it.second.wal_lsn > it.second.flush_lsn) {
-                lsn = last_applied_lsn_;
-                break;
+        for (auto& col : collections_) {
+            for (auto& part : col.second) {
+                if (part.second.wal_lsn > part.second.flush_lsn) {
+                    lsn = last_applied_lsn_;
+                    break;
+                }
             }
         }
 
     } else {
         // flush one collection
-        auto it = tables_.find(collection_id);
-        if (it != tables_.end()) {
-            if (it->second.wal_lsn > it->second.flush_lsn) {
-                lsn = it->second.wal_lsn;
+        auto it_col = collections_.find(collection_id);
+        if (it_col != collections_.end()) {
+            for (auto& part : it_col->second) {
+                auto wal_lsn = part.second.wal_lsn;
+                auto flush_lsn = part.second.flush_lsn;
+                if (wal_lsn > flush_lsn && wal_lsn > lsn) {
+                    lsn = wal_lsn;
+                }
             }
         }
     }

core/src/db/wal/WalManager.h

@@ -62,6 +62,7 @@ class WalManager {
 
     ErrorCode
     GetNextEntityRecord(MXLogRecord& record);
+
     /*
      * Create collection
      * @param collection_id: collection id
@@ -70,6 +71,15 @@ class WalManager {
     uint64_t
     CreateCollection(const std::string& collection_id);
 
+    /*
+     * Create partition
+     * @param collection_id: collection id
+     * @param partition_tag: partition tag
+     * @retval lsn
+     */
+    uint64_t
+    CreatePartition(const std::string& collection_id, const std::string& partition_tag);
+
     /*
      * Create hybrid collection
      * @param collection_id: collection id
@@ -87,13 +97,49 @@ class WalManager {
     DropCollection(const std::string& collection_id);
 
     /*
-     * Collection is flushed
+     * Drop partition
+     * @param collection_id: collection id
+     * @param partition_tag: partition tag
+     * @retval none
+     */
+    void
+    DropPartition(const std::string& collection_id, const std::string& partition_tag);
+
+    /*
+     * Collection is flushed (update flushed_lsn)
      * @param collection_id: collection id
      * @param lsn: flushed lsn
      */
     void
     CollectionFlushed(const std::string& collection_id, uint64_t lsn);
 
+    /*
+     * Partition is flushed (update flushed_lsn)
+     * @param collection_id: collection id
+     * @param partition_tag: partition_tag
+     * @param lsn: flushed lsn
+     */
+    void
+    PartitionFlushed(const std::string& collection_id, const std::string& partition_tag, uint64_t lsn);
+
+    /*
+     * Collection is updated (update wal_lsn)
+     * @param collection_id: collection id
+     * @param partition_tag: partition_tag
+     * @param lsn: flushed lsn
+     */
+    void
+    CollectionUpdated(const std::string& collection_id, uint64_t lsn);
+
+    /*
+     * Partition is updated (update wal_lsn)
+     * @param collection_id: collection id
+     * @param partition_tag: partition_tag
+     * @param lsn: flushed lsn
+     */
+    void
+    PartitionUpdated(const std::string& collection_id, const std::string& partition_tag, uint64_t lsn);
+
     /*
      * Insert
      * @param collection_id: collection id
@@ -155,7 +201,7 @@ class WalManager {
         uint64_t wal_lsn;
     };
     std::mutex mutex_;
-    std::map<std::string, TableLsn> tables_;
+    std::map<std::string, std::map<std::string, TableLsn>> collections_;
     std::atomic<uint64_t> last_applied_lsn_;
 
     // if multi-thread call Flush(), use list

core/unittest/db/test_wal.cpp

@@ -60,7 +60,7 @@ class TestWalMeta : public SqliteMetaImpl {
     }
 
     Status
-    AllCollections(std::vector<CollectionSchema>& table_schema_array) override {
+    AllCollections(std::vector<CollectionSchema>& table_schema_array, bool is_root) override {
         table_schema_array = tables_;
         return Status::OK();
     }
@@ -88,7 +88,7 @@ class TestWalMetaError : public SqliteMetaImpl {
     }
 
     Status
-    AllCollections(std::vector<CollectionSchema>& table_schema_array) override {
+    AllCollections(std::vector<CollectionSchema>& table_schema_array, bool is_root) override {
         return Status(DB_ERROR, "error");
     }
 };