diff --git a/orm_lib/src/DbClientImpl.cc b/orm_lib/src/DbClientImpl.cc
index 5e154b21c9..730c7c75fc 100644
--- a/orm_lib/src/DbClientImpl.cc
+++ b/orm_lib/src/DbClientImpl.cc
@@ -81,10 +81,7 @@ void DbClientImpl::init()
         for (size_t i = 0; i < numberOfConnections_; ++i)
         {
             auto loop = loops_.getNextLoop();
-            loop->runInLoop([this, loop]() {
-                std::lock_guard<std::mutex> lock(connectionsMutex_);
-                connections_.insert(newConnection(loop));
-            });
+            loop->runInLoop([this, loop]() { newConnection(loop); });
         }
     }
     else if (type_ == ClientType::Sqlite3)
@@ -92,10 +89,9 @@ void DbClientImpl::init()
         sharedMutexPtr_ = std::make_shared<SharedMutex>();
         assert(sharedMutexPtr_);
 
-        std::lock_guard<std::mutex> lock(connectionsMutex_);
         for (size_t i = 0; i < numberOfConnections_; ++i)
         {
-            connections_.insert(newConnection(nullptr));
+            newConnection(nullptr);
         }
     }
 }
@@ -405,12 +401,9 @@ DbConnectionPtr DbClientImpl::newConnection(trantor::EventLoop *loop)
     else if (type_ == ClientType::Sqlite3)
     {
 #if USE_SQLITE3
-        auto sqlite3ConnPtr =
-            std::make_shared<Sqlite3Connection>(loop,
-                                                connectionInfo_,
-                                                sharedMutexPtr_);
-        sqlite3ConnPtr->init();
-        connPtr = sqlite3ConnPtr;
+        connPtr = std::make_shared<Sqlite3Connection>(loop,
+                                                      connectionInfo_,
+                                                      sharedMutexPtr_);
 #else
         return nullptr;
 #endif
@@ -440,8 +433,8 @@ DbConnectionPtr DbClientImpl::newConnection(trantor::EventLoop *loop)
             auto thisPtr = weakPtr.lock();
             if (!thisPtr)
                 return;
-            std::lock_guard<std::mutex> guard(thisPtr->connectionsMutex_);
-            thisPtr->connections_.insert(thisPtr->newConnection(loop));
+
+            thisPtr->newConnection(loop);
         });
     });
     connPtr->setOkCallback([weakPtr](const DbConnectionPtr &okConnPtr) {
@@ -467,6 +460,16 @@ DbConnectionPtr DbClientImpl::newConnection(trantor::EventLoop *loop)
             return;
         thisPtr->handleNewTask(connPtr);
     });
+
+    {
+        std::lock_guard<std::mutex> guard(connectionsMutex_);
+        connections_.insert(connPtr);
+    }
+
+    // Init database connection only after all callbacks are set and connPtr
+    // is added to connections_.
+    connPtr->init();
+
     // std::cout<<"newConn end"<<connPtr<<std::endl;
     return connPtr;
 }
diff --git a/orm_lib/src/DbClientLockFree.cc b/orm_lib/src/DbClientLockFree.cc
index 427f762442..de0d248462 100644
--- a/orm_lib/src/DbClientLockFree.cc
+++ b/orm_lib/src/DbClientLockFree.cc
@@ -63,7 +63,7 @@ DbClientLockFree::DbClientLockFree(const std::string &connInfo,
     {
         loop_->queueInLoop([this]() {
             for (size_t i = 0; i < numberOfConnections_; ++i)
-                connectionHolders_.push_back(newConnection());
+                newConnection();
         });
     }
     else
@@ -439,26 +439,17 @@ DbConnectionPtr DbClientLockFree::newConnection()
         if (!thisPtr)
             return;
 
-        for (auto iter = thisPtr->connections_.begin();
-             iter != thisPtr->connections_.end();
-             iter++)
-        {
-            if (closeConnPtr == *iter)
-            {
-                thisPtr->connections_.erase(iter);
-                break;
-            }
-        }
-        for (auto iter = thisPtr->connectionHolders_.begin();
-             iter != thisPtr->connectionHolders_.end();
-             iter++)
-        {
-            if (closeConnPtr == *iter)
-            {
-                thisPtr->connectionHolders_.erase(iter);
-                break;
-            }
-        }
+        auto iter = std::find(thisPtr->connections_.begin(),
+                              thisPtr->connections_.end(),
+                              closeConnPtr);
+        if (iter != thisPtr->connections_.end())
+            thisPtr->connections_.erase(iter);
+
+        iter = std::find(thisPtr->connectionHolders_.begin(),
+                         thisPtr->connectionHolders_.end(),
+                         closeConnPtr);
+        if (iter != thisPtr->connectionHolders_.end())
+            thisPtr->connectionHolders_.erase(iter);
 
         thisPtr->transSet_.erase(closeConnPtr);
         // Reconnect after 1 second
@@ -466,7 +457,7 @@ DbConnectionPtr DbClientLockFree::newConnection()
             auto thisPtr = weakPtr.lock();
             if (!thisPtr)
                 return;
-            thisPtr->connectionHolders_.push_back(thisPtr->newConnection());
+            thisPtr->newConnection();
         });
     });
     connPtr->setOkCallback([weakPtr](const DbConnectionPtr &okConnPtr) {
@@ -487,6 +478,13 @@ DbConnectionPtr DbClientLockFree::newConnection()
             return;
         thisPtr->handleNewTask(connPtr);
     });
+
+    connectionHolders_.push_back(connPtr);
+
+    // Init database connection only after all callbacks are set and connPtr
+    // is added to connectionHolders_.
+    connPtr->init();
+
     // std::cout<<"newConn end"<<connPtr<<std::endl;
     return connPtr;
 }
diff --git a/orm_lib/src/DbConnection.h b/orm_lib/src/DbConnection.h
index 87bca7ba33..c49838a2a0 100644
--- a/orm_lib/src/DbConnection.h
+++ b/orm_lib/src/DbConnection.h
@@ -88,6 +88,8 @@ class DbConnection : public trantor::NonCopyable
     {
     }
 
+    virtual void init(){};
+
     void setOkCallback(const DbConnectionCallback &cb)
     {
         okCallback_ = cb;
diff --git a/orm_lib/src/mysql_impl/MysqlConnection.cc b/orm_lib/src/mysql_impl/MysqlConnection.cc
index c71f54110c..3c3d93242c 100644
--- a/orm_lib/src/mysql_impl/MysqlConnection.cc
+++ b/orm_lib/src/mysql_impl/MysqlConnection.cc
@@ -101,6 +101,10 @@ MysqlConnection::MysqlConnection(trantor::EventLoop *loop,
             characterSet_ = value;
         }
     }
+}
+
+void MysqlConnection::init()
+{
     loop_->queueInLoop([this]() {
         MYSQL *ret;
         status_ = ConnectStatus::Connecting;
@@ -120,10 +124,13 @@ MysqlConnection::MysqlConnection(trantor::EventLoop *loop,
         auto fd = mysql_get_socket(mysqlPtr_.get());
         if (fd < 0)
         {
-            LOG_FATAL << "Socket fd < 0, Usually this is because the number of "
-                         "files opened by the program exceeds the system "
-                         "limit. Please use the ulimit command to check.";
-            exit(1);
+            LOG_ERROR << "Connection with MySQL could not be established";
+            if (closeCallback_)
+            {
+                auto thisPtr = shared_from_this();
+                closeCallback_(thisPtr);
+            }
+            return;
         }
         channelPtr_ = std::make_unique<trantor::Channel>(loop_, fd);
         channelPtr_->setEventCallback([this]() { handleEvent(); });
diff --git a/orm_lib/src/mysql_impl/MysqlConnection.h b/orm_lib/src/mysql_impl/MysqlConnection.h
index 7f678513e4..4ec0c618a8 100644
--- a/orm_lib/src/mysql_impl/MysqlConnection.h
+++ b/orm_lib/src/mysql_impl/MysqlConnection.h
@@ -38,6 +38,8 @@ class MysqlConnection : public DbConnection,
   public:
     MysqlConnection(trantor::EventLoop *loop, const std::string &connInfo);
 
+    void init() override;
+
     ~MysqlConnection()
     {
     }
diff --git a/orm_lib/src/postgresql_impl/PgBatchConnection.cc b/orm_lib/src/postgresql_impl/PgBatchConnection.cc
index e29f9677df..631ef6907c 100644
--- a/orm_lib/src/postgresql_impl/PgBatchConnection.cc
+++ b/orm_lib/src/postgresql_impl/PgBatchConnection.cc
@@ -86,14 +86,22 @@ PgConnection::PgConnection(trantor::EventLoop *loop,
           std::shared_ptr<PGconn>(PQconnectStart(connInfo.c_str()),
                                   [](PGconn *conn) { PQfinish(conn); })),
       channel_(loop, PQsocket(connectionPtr_.get()))
+{
+}
+
+void PgConnection::init()
 {
     PQsetnonblocking(connectionPtr_.get(), 1);
     if (channel_.fd() < 0)
     {
-        LOG_FATAL << "Socket fd < 0, Usually this is because the number of "
-                     "files opened by the program exceeds the system "
-                     "limit. Please use the ulimit command to check.";
-        exit(1);
+        LOG_ERROR << "Connection with Postgres could not be established";
+
+        if (closeCallback_)
+        {
+            auto thisPtr = shared_from_this();
+            closeCallback_(thisPtr);
+        }
+        return;
     }
     channel_.setReadCallback([this]() {
         if (status_ == ConnectStatus::Bad)
diff --git a/orm_lib/src/postgresql_impl/PgConnection.cc b/orm_lib/src/postgresql_impl/PgConnection.cc
index 40c0b252a1..59d080cc71 100644
--- a/orm_lib/src/postgresql_impl/PgConnection.cc
+++ b/orm_lib/src/postgresql_impl/PgConnection.cc
@@ -64,14 +64,21 @@ PgConnection::PgConnection(trantor::EventLoop *loop,
           std::shared_ptr<PGconn>(PQconnectStart(connInfo.c_str()),
                                   [](PGconn *conn) { PQfinish(conn); })),
       channel_(loop, PQsocket(connectionPtr_.get()))
+{
+}
+
+void PgConnection::init()
 {
     PQsetnonblocking(connectionPtr_.get(), 1);
     if (channel_.fd() < 0)
     {
-        LOG_FATAL << "Socket fd < 0, Usually this is because the number of "
-                     "files opened by the program exceeds the system "
-                     "limit. Please use the ulimit command to check.";
-        exit(1);
+        LOG_ERROR << "Connection with Postgres could not be established";
+        if (closeCallback_)
+        {
+            auto thisPtr = shared_from_this();
+            closeCallback_(thisPtr);
+        }
+        return;
     }
     channel_.setReadCallback([this]() {
         if (status_ == ConnectStatus::Bad)
diff --git a/orm_lib/src/postgresql_impl/PgConnection.h b/orm_lib/src/postgresql_impl/PgConnection.h
index 3c70e6a526..b962ec297e 100644
--- a/orm_lib/src/postgresql_impl/PgConnection.h
+++ b/orm_lib/src/postgresql_impl/PgConnection.h
@@ -45,6 +45,8 @@ class PgConnection : public DbConnection,
                  const std::string &connInfo,
                  bool autoBatch);
 
+    void init() override;
+
     void execSql(std::string_view &&sql,
                  size_t paraNum,
                  std::vector<const char *> &&parameters,
diff --git a/orm_lib/src/postgresql_impl/PgListener.cc b/orm_lib/src/postgresql_impl/PgListener.cc
index 4c1bde96e7..8a91088ddc 100644
--- a/orm_lib/src/postgresql_impl/PgListener.cc
+++ b/orm_lib/src/postgresql_impl/PgListener.cc
@@ -302,6 +302,7 @@ PgConnectionPtr PgListener::newConnection(
                 thisPtr->onMessage(channel, message);
             }
         });
+    connPtr->init();
     return connPtr;
 }
 
diff --git a/orm_lib/src/sqlite3_impl/Sqlite3Connection.h b/orm_lib/src/sqlite3_impl/Sqlite3Connection.h
index b9c284303d..8f3ed834af 100644
--- a/orm_lib/src/sqlite3_impl/Sqlite3Connection.h
+++ b/orm_lib/src/sqlite3_impl/Sqlite3Connection.h
@@ -44,6 +44,8 @@ class Sqlite3Connection : public DbConnection,
                       const std::string &connInfo,
                       const std::shared_ptr<SharedMutex> &sharedMutex);
 
+    void init() override;
+
     void execSql(std::string_view &&sql,
                  size_t paraNum,
                  std::vector<const char *> &&parameters,
@@ -60,7 +62,6 @@ class Sqlite3Connection : public DbConnection,
     }
 
     void disconnect() override;
-    void init();
 
   private:
     static std::once_flag once_;