diff --git a/services/tunnelbroker/src/Database/DatabaseManager.cpp b/services/tunnelbroker/src/Database/DatabaseManager.cpp
index 285a0abbc..a7c31cb67 100644
--- a/services/tunnelbroker/src/Database/DatabaseManager.cpp
+++ b/services/tunnelbroker/src/Database/DatabaseManager.cpp
@@ -1,241 +1,213 @@
 #include "DatabaseManager.h"
 #include "DynamoDBTools.h"
 
 namespace comm {
 namespace network {
 namespace database {
 
 DatabaseManager &DatabaseManager::getInstance() {
   static DatabaseManager instance;
   return instance;
 }
 
 bool DatabaseManager::isTableAvailable(const std::string &tableName) {
   Aws::DynamoDB::Model::DescribeTableRequest request;
   request.SetTableName(tableName);
 
   // Check table availability by invoking DescribeTable
   const Aws::DynamoDB::Model::DescribeTableOutcome &result =
       getDynamoDBClient()->DescribeTable(request);
   return result.IsSuccess();
 }
 
-void DatabaseManager::innerPutItem(
-    std::shared_ptr<Item> item,
-    const Aws::DynamoDB::Model::PutItemRequest &request) {
-  const Aws::DynamoDB::Model::PutItemOutcome outcome =
-      getDynamoDBClient()->PutItem(request);
-  if (!outcome.IsSuccess()) {
-    throw std::runtime_error(outcome.GetError().GetMessage());
-  }
-}
-
-template <typename T>
-std::shared_ptr<T>
-DatabaseManager::innerFindItem(Aws::DynamoDB::Model::GetItemRequest &request) {
-  std::shared_ptr<T> item = createItemByType<T>();
-  request.SetTableName(item->getTableName());
-  const Aws::DynamoDB::Model::GetItemOutcome &outcome =
-      getDynamoDBClient()->GetItem(request);
-  if (!outcome.IsSuccess()) {
-    throw std::runtime_error(outcome.GetError().GetMessage());
-  }
-  const AttributeValues &outcomeItem = outcome.GetResult().GetItem();
-  if (!outcomeItem.size()) {
-    return nullptr;
-  }
-  item->assignItemFromDatabase(outcomeItem);
-  return std::move(item);
-}
-
-void DatabaseManager::innerRemoveItem(
-    const Item &item,
-    const std::string &key) {
-  Aws::DynamoDB::Model::DeleteItemRequest request;
-  request.SetTableName(item.getTableName());
-  request.AddKey(
-      item.getPrimaryKey().partitionKey,
-      Aws::DynamoDB::Model::AttributeValue(key));
-
-  const Aws::DynamoDB::Model::DeleteItemOutcome &outcome =
-      getDynamoDBClient()->DeleteItem(request);
-  if (!outcome.IsSuccess()) {
-    throw std::runtime_error(outcome.GetError().GetMessage());
-  }
-}
-
 void DatabaseManager::putSessionItem(const DeviceSessionItem &item) {
   Aws::DynamoDB::Model::PutItemRequest request;
   request.SetTableName(item.getTableName());
   request.AddItem(
       DeviceSessionItem::FIELD_SESSION_ID,
       Aws::DynamoDB::Model::AttributeValue(item.getSessionID()));
   request.AddItem(
       DeviceSessionItem::FIELD_DEVICE_ID,
       Aws::DynamoDB::Model::AttributeValue(item.getDeviceID()));
   request.AddItem(
       DeviceSessionItem::FIELD_PUBKEY,
       Aws::DynamoDB::Model::AttributeValue(item.getPubKey()));
   request.AddItem(
       DeviceSessionItem::FIELD_NOTIFY_TOKEN,
       Aws::DynamoDB::Model::AttributeValue(item.getNotifyToken()));
   request.AddItem(
       DeviceSessionItem::FIELD_DEVICE_TYPE,
       Aws::DynamoDB::Model::AttributeValue(item.getDeviceType()));
   request.AddItem(
       DeviceSessionItem::FIELD_APP_VERSION,
       Aws::DynamoDB::Model::AttributeValue(item.getAppVersion()));
   request.AddItem(
       DeviceSessionItem::FIELD_DEVICE_OS,
       Aws::DynamoDB::Model::AttributeValue(item.getDeviceOs()));
   request.AddItem(
       DeviceSessionItem::FIELD_CHECKPOINT_TIME,
       Aws::DynamoDB::Model::AttributeValue(
           std::to_string(item.getCheckpointTime())));
   request.AddItem(
       DeviceSessionItem::FIELD_EXPIRE,
       Aws::DynamoDB::Model::AttributeValue(std::to_string(
           static_cast<size_t>(std::time(0)) + SESSION_RECORD_TTL)));
   this->innerPutItem(std::make_shared<DeviceSessionItem>(item), request);
 }
 
 std::shared_ptr<DeviceSessionItem>
 DatabaseManager::findSessionItem(const std::string &sessionID) {
   Aws::DynamoDB::Model::GetItemRequest request;
   request.AddKey(
       DeviceSessionItem::FIELD_SESSION_ID,
       Aws::DynamoDB::Model::AttributeValue(sessionID));
   return std::move(this->innerFindItem<DeviceSessionItem>(request));
 }
 
 void DatabaseManager::removeSessionItem(const std::string &sessionID) {
-  this->innerRemoveItem(*(createItemByType<DeviceSessionItem>()), sessionID);
+  std::shared_ptr<DeviceSessionItem> item = this->findSessionItem(sessionID);
+  if (item == nullptr) {
+    return;
+  }
+  this->innerRemoveItem(*item);
 }
 
 void DatabaseManager::putSessionSignItem(const SessionSignItem &item) {
   Aws::DynamoDB::Model::PutItemRequest request;
   request.SetTableName(item.getTableName());
   request.AddItem(
       SessionSignItem::FIELD_SESSION_VERIFICATION,
       Aws::DynamoDB::Model::AttributeValue(item.getSign()));
   request.AddItem(
       SessionSignItem::FIELD_DEVICE_ID,
       Aws::DynamoDB::Model::AttributeValue(item.getDeviceID()));
   request.AddItem(
       SessionSignItem::FIELD_EXPIRE,
       Aws::DynamoDB::Model::AttributeValue(std::to_string(
           static_cast<size_t>(std::time(0)) + SESSION_SIGN_RECORD_TTL)));
   this->innerPutItem(std::make_shared<SessionSignItem>(item), request);
 }
 
 std::shared_ptr<SessionSignItem>
 DatabaseManager::findSessionSignItem(const std::string &deviceID) {
   Aws::DynamoDB::Model::GetItemRequest request;
   request.AddKey(
       SessionSignItem::FIELD_DEVICE_ID,
       Aws::DynamoDB::Model::AttributeValue(deviceID));
   return std::move(this->innerFindItem<SessionSignItem>(request));
 }
 
 void DatabaseManager::removeSessionSignItem(const std::string &deviceID) {
-  this->innerRemoveItem(*(createItemByType<SessionSignItem>()), deviceID);
+  std::shared_ptr<SessionSignItem> item = this->findSessionSignItem(deviceID);
+  if (item == nullptr) {
+    return;
+  }
+  this->innerRemoveItem(*item);
 }
 
 void DatabaseManager::putPublicKeyItem(const PublicKeyItem &item) {
   Aws::DynamoDB::Model::PutItemRequest request;
   request.SetTableName(item.getTableName());
   request.AddItem(
       PublicKeyItem::FIELD_DEVICE_ID,
       Aws::DynamoDB::Model::AttributeValue(item.getDeviceID()));
   request.AddItem(
       PublicKeyItem::FIELD_PUBLIC_KEY,
       Aws::DynamoDB::Model::AttributeValue(item.getPublicKey()));
   this->innerPutItem(std::make_shared<PublicKeyItem>(item), request);
 }
 
 std::shared_ptr<PublicKeyItem>
 DatabaseManager::findPublicKeyItem(const std::string &deviceID) {
   Aws::DynamoDB::Model::GetItemRequest request;
   request.AddKey(
       PublicKeyItem::FIELD_DEVICE_ID,
       Aws::DynamoDB::Model::AttributeValue(deviceID));
   return std::move(this->innerFindItem<PublicKeyItem>(request));
 }
 
 void DatabaseManager::removePublicKeyItem(const std::string &deviceID) {
-  this->innerRemoveItem(*(createItemByType<PublicKeyItem>()), deviceID);
+  std::shared_ptr<PublicKeyItem> item = this->findPublicKeyItem(deviceID);
+  if (item == nullptr) {
+    return;
+  }
+  this->innerRemoveItem(*item);
 }
 
 void DatabaseManager::putMessageItem(const MessageItem &item) {
   Aws::DynamoDB::Model::PutItemRequest request;
   request.SetTableName(item.getTableName());
   request.AddItem(
       MessageItem::FIELD_MESSAGE_ID,
       Aws::DynamoDB::Model::AttributeValue(item.getMessageID()));
   request.AddItem(
       MessageItem::FIELD_FROM_DEVICE_ID,
       Aws::DynamoDB::Model::AttributeValue(item.getFromDeviceID()));
   request.AddItem(
       MessageItem::FIELD_TO_DEVICE_ID,
       Aws::DynamoDB::Model::AttributeValue(item.getToDeviceID()));
   request.AddItem(
       MessageItem::FIELD_PAYLOAD,
       Aws::DynamoDB::Model::AttributeValue(item.getPayload()));
   request.AddItem(
       MessageItem::FIELD_BLOB_HASHES,
       Aws::DynamoDB::Model::AttributeValue(item.getBlobHashes()));
   request.AddItem(
       MessageItem::FIELD_EXPIRE,
       Aws::DynamoDB::Model::AttributeValue(std::to_string(
           static_cast<size_t>(std::time(0) + MESSAGE_RECORD_TTL))));
   request.AddItem(
       MessageItem::FIELD_CREATED_AT,
       Aws::DynamoDB::Model::AttributeValue(
           std::to_string(tools::getCurrentTimestamp())));
   this->innerPutItem(std::make_shared<MessageItem>(item), request);
 }
 
 std::shared_ptr<MessageItem>
 DatabaseManager::findMessageItem(const std::string &messageID) {
   Aws::DynamoDB::Model::GetItemRequest request;
   request.AddKey(
       MessageItem::FIELD_MESSAGE_ID,
       Aws::DynamoDB::Model::AttributeValue(messageID));
   return std::move(this->innerFindItem<MessageItem>(request));
 }
 
 std::vector<std::shared_ptr<MessageItem>>
 DatabaseManager::findMessageItemsByReceiver(const std::string &toDeviceID) {
   std::vector<std::shared_ptr<MessageItem>> result;
 
   Aws::DynamoDB::Model::QueryRequest req;
   req.SetTableName(MessageItem().getTableName());
   req.SetKeyConditionExpression(
       MessageItem::FIELD_TO_DEVICE_ID + " = :valueToMatch");
 
   AttributeValues attributeValues;
   attributeValues.emplace(":valueToMatch", toDeviceID);
 
   req.SetExpressionAttributeValues(attributeValues);
   req.SetIndexName(MessageItem::INDEX_TO_DEVICE_ID);
 
   const Aws::DynamoDB::Model::QueryOutcome &outcome =
       getDynamoDBClient()->Query(req);
   if (!outcome.IsSuccess()) {
     throw std::runtime_error(outcome.GetError().GetMessage());
   }
   const Aws::Vector<AttributeValues> &items = outcome.GetResult().GetItems();
   for (auto &item : items) {
     result.push_back(std::make_shared<MessageItem>(item));
   }
 
   return result;
 }
 
 void DatabaseManager::removeMessageItem(const std::string &messageID) {
-  this->innerRemoveItem(*(createItemByType<MessageItem>()), messageID);
+  std::shared_ptr<MessageItem> item = this->findMessageItem(messageID);
+  if (item == nullptr) {
+    return;
+  }
+  this->innerRemoveItem(*item);
 }
 
 } // namespace database
 } // namespace network
 } // namespace comm
diff --git a/services/tunnelbroker/src/Database/DatabaseManager.h b/services/tunnelbroker/src/Database/DatabaseManager.h
index 13d5a6a13..22ab683cf 100644
--- a/services/tunnelbroker/src/Database/DatabaseManager.h
+++ b/services/tunnelbroker/src/Database/DatabaseManager.h
@@ -1,62 +1,54 @@
 #pragma once
 
 #include "AwsTools.h"
 #include "Constants.h"
 #include "DatabaseEntitiesTools.h"
+#include "DatabaseManagerBase.h"
 #include "Tools.h"
 
 #include <aws/core/Aws.h>
 #include <aws/core/utils/Outcome.h>
 #include <aws/dynamodb/model/AttributeDefinition.h>
 #include <aws/dynamodb/model/DeleteItemRequest.h>
 #include <aws/dynamodb/model/DescribeTableRequest.h>
 #include <aws/dynamodb/model/DescribeTableResult.h>
 #include <aws/dynamodb/model/GetItemRequest.h>
 #include <aws/dynamodb/model/PutItemRequest.h>
 #include <aws/dynamodb/model/QueryRequest.h>
 
 #include <memory>
 #include <string>
 
 namespace comm {
 namespace network {
 namespace database {
 
-class DatabaseManager {
-
-  void innerPutItem(
-      std::shared_ptr<Item> item,
-      const Aws::DynamoDB::Model::PutItemRequest &request);
-  template <typename T>
-  std::shared_ptr<T>
-  innerFindItem(Aws::DynamoDB::Model::GetItemRequest &request);
-  void innerRemoveItem(const Item &item, const std::string &key);
-
+class DatabaseManager : public DatabaseManagerBase {
 public:
   static DatabaseManager &getInstance();
   bool isTableAvailable(const std::string &tableName);
 
   void putSessionItem(const DeviceSessionItem &item);
   std::shared_ptr<DeviceSessionItem>
   findSessionItem(const std::string &deviceID);
   void removeSessionItem(const std::string &sessionID);
 
   void putSessionSignItem(const SessionSignItem &item);
   std::shared_ptr<SessionSignItem>
   findSessionSignItem(const std::string &deviceID);
   void removeSessionSignItem(const std::string &deviceID);
 
   void putPublicKeyItem(const PublicKeyItem &item);
   std::shared_ptr<PublicKeyItem> findPublicKeyItem(const std::string &deviceID);
   void removePublicKeyItem(const std::string &deviceID);
 
   void putMessageItem(const MessageItem &item);
   std::shared_ptr<MessageItem> findMessageItem(const std::string &messageID);
   std::vector<std::shared_ptr<MessageItem>>
   findMessageItemsByReceiver(const std::string &toDeviceID);
   void removeMessageItem(const std::string &messageID);
 };
 
 } // namespace database
 } // namespace network
 } // namespace comm