From ff663dc511a5daf955e559cdff0d47fa6a07f104 Mon Sep 17 00:00:00 2001
From: alesapin <alesapin@gmail.com>
Date: Wed, 17 Feb 2021 23:36:25 +0300
Subject: [PATCH] Fsync at server shutdown

---
 src/Coordination/Changelog.cpp            | 13 ++++++++++++-
 src/Coordination/InMemoryStateManager.cpp |  5 +++++
 src/Coordination/InMemoryStateManager.h   |  2 ++
 src/Coordination/NuKeeperServer.cpp       |  1 +
 4 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/src/Coordination/Changelog.cpp b/src/Coordination/Changelog.cpp
index a9693b2a47b..2d1bbfb4440 100644
--- a/src/Coordination/Changelog.cpp
+++ b/src/Coordination/Changelog.cpp
@@ -467,6 +467,17 @@ void Changelog::flush()
     current_writer->flush();
 }
 
-Changelog::~Changelog() = default;
+Changelog::~Changelog()
+{
+    try
+    {
+        if (current_writer)
+            current_writer->flush();
+    }
+    catch (...)
+    {
+        tryLogCurrentException(__PRETTY_FUNCTION__);
+    }
+}
 
 }
diff --git a/src/Coordination/InMemoryStateManager.cpp b/src/Coordination/InMemoryStateManager.cpp
index 6c4e95b993a..0423d2466f2 100644
--- a/src/Coordination/InMemoryStateManager.cpp
+++ b/src/Coordination/InMemoryStateManager.cpp
@@ -66,6 +66,11 @@ void InMemoryStateManager::loadLogStore(size_t start_log_index)
     log_store->init(start_log_index);
 }
 
+void InMemoryStateManager::flushLogStore()
+{
+    log_store->flush();
+}
+
 void InMemoryStateManager::save_config(const nuraft::cluster_config & config)
 {
     // Just keep in memory in this example.
diff --git a/src/Coordination/InMemoryStateManager.h b/src/Coordination/InMemoryStateManager.h
index 8a7be7d0129..c53f00702d4 100644
--- a/src/Coordination/InMemoryStateManager.h
+++ b/src/Coordination/InMemoryStateManager.h
@@ -27,6 +27,8 @@ public:
 
     void loadLogStore(size_t start_log_index);
 
+    void flushLogStore();
+
     nuraft::ptr<nuraft::cluster_config> load_config() override { return cluster_config; }
 
     void save_config(const nuraft::cluster_config & config) override;
diff --git a/src/Coordination/NuKeeperServer.cpp b/src/Coordination/NuKeeperServer.cpp
index a4582a5fbb8..8556fa85231 100644
--- a/src/Coordination/NuKeeperServer.cpp
+++ b/src/Coordination/NuKeeperServer.cpp
@@ -67,6 +67,7 @@ void NuKeeperServer::startup()
 void NuKeeperServer::shutdown()
 {
     state_machine->shutdownStorage();
+    state_manager->flushLogStore();
     if (!launcher.shutdown(coordination_settings->shutdown_timeout.totalSeconds()))
         LOG_WARNING(&Poco::Logger::get("NuKeeperServer"), "Failed to shutdown RAFT server in {} seconds", 5);
 }