write settings on shutdown

arangod/RocksDBEngine/RocksDBBackgroundThread.cpp

@@ -51,8 +51,6 @@ void RocksDBBackgroundThread::run() {
       guard.wait(static_cast<uint64_t>(_interval * 1000000.0));
     }
 
-    _engine->counterManager()->writeSettings();
-
     if (!isStopping()) {
       _engine->counterManager()->sync(false);
     }
@@ -67,5 +65,5 @@ void RocksDBBackgroundThread::run() {
           });
     }
   }
-  _engine->counterManager()->writeSettings();  // final write on shutdown
+  _engine->counterManager()->sync(true); // final write on shutdown
 }

arangod/RocksDBEngine/RocksDBCounterManager.cpp

@@ -165,10 +165,6 @@ void RocksDBCounterManager::removeCounter(uint64_t objectId) {
 
 /// Thread-Safe force sync
 Result RocksDBCounterManager::sync(bool force) {
-#if 0
-  writeSettings();
-#endif
-
   if (force) {
     while (true) {
       bool expected = false;
@@ -218,12 +214,34 @@ Result RocksDBCounterManager::sync(bool force) {
     rocksdb::Status s = rtrx->Put(key.string(), value);
     if (!s.ok()) {
       rtrx->Rollback();
+      LOG_TOPIC(WARN, Logger::ENGINES) << "writing counters failed";
       return rocksutils::convertStatus(s);
     }
   }
     
+  // now write global settings
+  b.clear();
+  b.openObject();
+  b.add("tick", VPackValue(std::to_string(TRI_CurrentTickServer())));
+  b.add("hlc", VPackValue(std::to_string(TRI_HybridLogicalClock())));
+  b.close();
+
+  VPackSlice slice = b.slice();
+  LOG_TOPIC(TRACE, Logger::ENGINES) << "writing settings: " << slice.toJson();
+
+  RocksDBKey key = RocksDBKey::SettingsValue();
+  rocksdb::Slice value(slice.startAs<char>(), slice.byteSize());
+
+  rocksdb::Status s = rtrx->Put(key.string(), value);
+
+  if (!s.ok()) {
+    LOG_TOPIC(WARN, Logger::ENGINES) << "writing settings failed";
+    rtrx->Rollback();
+    return rocksutils::convertStatus(s);
+  }
+
   // we have to commit all counters in one batch
-  rocksdb::Status s = rtrx->Commit();
+  s = rtrx->Commit();
   if (s.ok()) {
     for (std::pair<uint64_t, CMValue> const& pair : copy) {
       _syncedSeqNums[pair.first] = pair.second._sequenceNum;
@@ -252,6 +270,13 @@ void RocksDBCounterManager::readSettings() {
             basics::VelocyPackHelper::stringUInt64(slice.get("tick"));
         LOG_TOPIC(TRACE, Logger::ENGINES) << "using last tick: " << lastTick;
         TRI_UpdateTickServer(lastTick);
+        
+        if (slice.hasKey("hlc")) {
+          uint64_t lastHlc =
+              basics::VelocyPackHelper::stringUInt64(slice.get("hlc"));
+          LOG_TOPIC(TRACE, Logger::ENGINES) << "using last hlc: " << lastHlc;
+          TRI_HybridLogicalClock(lastHlc);
+        }
       } catch (...) {
         LOG_TOPIC(WARN, Logger::ENGINES)
             << "unable to read initial settings: invalid data";
@@ -260,27 +285,6 @@ void RocksDBCounterManager::readSettings() {
   }
 }
 
-void RocksDBCounterManager::writeSettings() {
-  RocksDBKey key = RocksDBKey::SettingsValue();
-
-  VPackBuilder builder;
-  builder.openObject();
-  builder.add("tick", VPackValue(std::to_string(TRI_CurrentTickServer())));
-  builder.close();
-
-  VPackSlice slice = builder.slice();
-  LOG_TOPIC(TRACE, Logger::ENGINES) << "writing settings: " << slice.toJson();
-
-  rocksdb::Slice value(slice.startAs<char>(), slice.byteSize());
-
-  rocksdb::Status status =
-      _db->Put(rocksdb::WriteOptions(), key.string(), value);
-
-  if (!status.ok()) {
-    LOG_TOPIC(TRACE, Logger::ENGINES) << "writing settings failed";
-  }
-}
-
 /// Parse counter values from rocksdb
 void RocksDBCounterManager::readCounterValues() {
   WRITE_LOCKER(guard, _rwLock);
@@ -311,10 +315,10 @@ struct WBReader : public rocksdb::WriteBatch::Handler {
   uint64_t _maxTick = 0;
   uint64_t _maxHLC = 0;
 
-  explicit WBReader() : currentSeqNum(0) {}
+  WBReader() : currentSeqNum(0) {}
   virtual ~WBReader() {
     // update ticks after parsing wal
-    TRI_UpdateTickServer(std::max(_maxTick, TRI_CurrentTickServer()));
+    TRI_UpdateTickServer(_maxTick);
     TRI_HybridLogicalClock(_maxHLC);
   }
 

arangod/RocksDBEngine/RocksDBCounterManager.h

@@ -88,7 +88,6 @@ class RocksDBCounterManager {
   arangodb::Result sync(bool force);
 
   void readSettings();
-  void writeSettings();
 
  protected:
   struct CMValue {

arangod/RocksDBEngine/RocksDBEngine.cpp

@@ -204,7 +204,7 @@ void RocksDBEngine::start() {
   _options.comparator = _cmp.get();
   // WAL_ttl_seconds needs to be bigger than the sync interval of the count
   // manager. Should be several times bigger counter_sync_seconds
-  _options.WAL_ttl_seconds = 600;  //(uint64_t)(counter_sync_seconds * 2.0);
+  _options.WAL_ttl_seconds = 10; //600;  //(uint64_t)(counter_sync_seconds * 2.0);
   double counter_sync_seconds = 2.5;
   // TODO: prefix_extractior +  memtable_insert_with_hint_prefix