Database backend configuration

.github/workflows/unit_tests.yml

@@ -12,7 +12,7 @@ jobs:
         RELEASE:
           - ${{ startsWith(github.ref, 'refs/tags/') }}
     env:
-      BACKEND: ${{ matrix.BACKEND }}
+      NANO_BACKEND: ${{ matrix.BACKEND }}
       BUILD_TYPE: ${{ matrix.RELEASE && 'RelWithDebInfo' || 'Debug' }}
       TEST_USE_ROCKSDB: ${{ matrix.BACKEND == 'rocksdb' && '1' || '0' }}
       DEADLINE_SCALE_FACTOR: ${{ matrix.BACKEND == 'rocksdb' && '2' || '1' }}

nano/lib/rocksdbconfig.cpp

@@ -4,7 +4,6 @@
 
 nano::error nano::rocksdb_config::serialize_toml (nano::tomlconfig & toml) const
 {
-	toml.put ("enable", enable, "Whether to use the RocksDB backend for the ledger database.\ntype:bool");
 	toml.put ("io_threads", io_threads, "Number of threads to use with the background compaction and flushing.\ntype:uint32");
 	toml.put ("read_cache", read_cache, "Amount of megabytes per table allocated to read cache. Valid range is 1 - 1024. Default is 32.\nCarefully monitor memory usage if non-default values are used\ntype:long");
 	toml.put ("write_cache", write_cache, "Total amount of megabytes allocated to write cache. Valid range is 1 - 256. Default is 64.\nCarefully monitor memory usage if non-default values are used\ntype:long");
@@ -14,7 +13,7 @@ nano::error nano::rocksdb_config::serialize_toml (nano::tomlconfig & toml) const
 
 nano::error nano::rocksdb_config::deserialize_toml (nano::tomlconfig & toml)
 {
-	toml.get_optional<bool> ("enable", enable);
+	toml.get_optional<bool> ("enable", enable); // TODO: This setting can be removed in future versions
 	toml.get_optional<unsigned> ("io_threads", io_threads);
 	toml.get_optional<long> ("read_cache", read_cache);
 	toml.get_optional<long> ("write_cache", write_cache);

nano/node/make_store.cpp

@@ -4,12 +4,19 @@
 #include <nano/store/lmdb/lmdb.hpp>
 #include <nano/store/rocksdb/rocksdb.hpp>
 
-std::unique_ptr<nano::store::component> nano::make_store (nano::logger & logger, std::filesystem::path const & path, nano::ledger_constants & constants, bool read_only, bool add_db_postfix, nano::node_config const & node_config)
+std::unique_ptr<nano::store::component> nano::make_store (nano::logger & logger, std::filesystem::path const & path, nano::ledger_constants & constants, bool read_only, bool add_db_postfix, nano::node_config node_config)
 {
-	if (node_config.rocksdb_config.enable)
+	if (node_config.database_backend == nano::database_backend::rocksdb)
 	{
 		return std::make_unique<nano::store::rocksdb::component> (logger, add_db_postfix ? path / "rocksdb" : path, constants, node_config.rocksdb_config, read_only);
 	}
+	if (node_config.rocksdb_config.enable && node_config.database_backend == nano::database_backend::lmdb)
+	{
+		// rocksdb.enable is true in config, but database_backend is set to LMDB in config
+		logger.warn (nano::log::type::config, "Use of deprecated RocksDb setting detected in config file.\nPlease edit node_config.toml and use the new 'database_backend' to enable RocksDb");
+		node_config.database_backend = nano::database_backend::rocksdb;
+		return std::make_unique<nano::store::rocksdb::component> (logger, add_db_postfix ? path / "rocksdb" : path, constants, node_config.rocksdb_config, read_only);
+	}
 
 	return std::make_unique<nano::store::lmdb::component> (logger, add_db_postfix ? path / "data.ldb" : path, constants, node_config.diagnostics_config.txn_tracking, node_config.block_processor_batch_max_time, node_config.lmdb_config, node_config.backup_before_upgrade);
 }

nano/node/make_store.hpp

@@ -23,5 +23,5 @@ class component;
 
 namespace nano
 {
-std::unique_ptr<nano::store::component> make_store (nano::logger &, std::filesystem::path const & path, nano::ledger_constants & constants, bool read_only = false, bool add_db_postfix = true, nano::node_config const & node_config = nano::node_config{});
+std::unique_ptr<nano::store::component> make_store (nano::logger &, std::filesystem::path const & path, nano::ledger_constants & constants, bool read_only = false, bool add_db_postfix = true, nano::node_config node_config = nano::node_config{});
 }

nano/node/nodeconfig.cpp

@@ -537,6 +537,8 @@ nano::error nano::node_config::deserialize_toml (nano::tomlconfig & toml)
 		toml.get<bool> ("allow_local_peers", allow_local_peers);
 		toml.get<unsigned> (signature_checker_threads_key, signature_checker_threads);
 
+		database_backend = get_config_backend (toml);
+
 		if (toml.has_key ("lmdb"))
 		{
 			auto lmdb_config_l (toml.get_required_child ("lmdb"));
@@ -659,6 +661,62 @@ void nano::node_config::deserialize_address (std::string const & entry_a, std::v
 	}
 }
 
+std::string nano::node_config::serialize_database_backend (nano::database_backend backend) const
+{
+	switch (backend)
+	{
+		case nano::database_backend::rocksdb:
+			return "rocksdb";
+		case nano::database_backend::lmdb:
+			return "lmdb";
+	}
+	debug_assert (false);
+}
+
+std::optional<nano::database_backend> nano::node_config::deserialize_database_backend (std::string backend_str) const
+{
+	if (backend_str == "rocksdb")
+		return database_backend::rocksdb;
+	if (backend_str == "lmdb")
+		return database_backend::lmdb;
+	return std::nullopt;
+}
+
+nano::database_backend nano::node_config::get_config_backend (nano::tomlconfig & toml)
+{
+	if (toml.has_key ("database_backend"))
+	{
+		auto backend_str = (toml.get<std::string> ("database_backend"));
+		auto backend = deserialize_database_backend (backend_str);
+		if (backend.has_value ())
+		{
+			return backend.value ();
+		}
+		toml.get_error ().set ("Unknown database_backend type: " + backend_str);
+		return nano::database_backend::lmdb;
+	}
+	// Default to LMDB
+	return nano::database_backend::lmdb;
+}
+
+nano::database_backend nano::node_config::get_default_backend ()
+{
+	auto backend_str = nano::env::get<std::string> ("NANO_BACKEND");
+
+	if (backend_str.has_value ())
+	{
+		auto backend = deserialize_database_backend (backend_str.value ());
+		if (backend.has_value ())
+		{
+			std::cerr << "Database backend overridden by NANO_BACKEND environment variable: " << *backend_str << std::endl;
+			return backend.value ();
+		}
+
+		std::cerr << "Unknown database backend in NANO_BACKEND environment variable: " << *backend_str << std::endl;
+	}
+	return database_backend::lmdb;
+}
+
 nano::account nano::node_config::random_representative () const
 {
 	debug_assert (!preconfigured_representatives.empty ());

nano/node/nodeconfig.hpp

@@ -43,6 +43,12 @@ namespace nano
 {
 class tomlconfig;
 
+enum class database_backend
+{
+	lmdb,
+	rocksdb
+};
+
 /**
  * Node configuration
  */
@@ -133,6 +139,7 @@ class node_config
 	uint64_t max_pruning_depth{ 0 };
 	nano::rocksdb_config rocksdb_config;
 	nano::lmdb_config lmdb_config;
+	nano::database_backend database_backend{ get_default_backend () };
 	bool enable_upnp{ true };
 	std::size_t max_ledger_notifications{ 8 };
 
@@ -156,6 +163,10 @@ class node_config
 public:
 	/** Entry is ignored if it cannot be parsed as a valid address:port */
 	void deserialize_address (std::string const &, std::vector<std::pair<std::string, uint16_t>> &) const;
+	std::string serialize_database_backend (nano::database_backend) const;
+	std::optional<nano::database_backend> deserialize_database_backend (std::string backend_str) const;
+	nano::database_backend get_config_backend (nano::tomlconfig & toml);
+	nano::database_backend get_default_backend ();
 
 private:
 	static std::optional<unsigned> env_io_threads ();

nano/secure/ledger.cpp

@@ -1304,7 +1304,7 @@ bool nano::ledger::migrate_lmdb_to_rocksdb (std::filesystem::path const & data_p
 
 	// Open rocksdb database
 	nano::node_config node_config;
-	node_config.rocksdb_config.enable = true;
+	node_config.database_backend = database_backend::rocksdb;
 	auto rocksdb_store = nano::make_store (logger, data_path_a, nano::dev::constants, false, true, node_config);
 
 	if (!rocksdb_store->init_error ())
@@ -1487,7 +1487,7 @@ bool nano::ledger::migrate_lmdb_to_rocksdb (std::filesystem::path const & data_p
 			}
 		}
 
-		logger.info (nano::log::type::ledger, "Migration completed. Make sure to enable RocksDB in the config file under [node.rocksdb]");
+		logger.info (nano::log::type::ledger, "Migration completed. Make sure to update [node.database_backend] to 'rocksdb' in config.toml");
 		logger.info (nano::log::type::ledger, "After confirming correct node operation, the data.ldb file can be deleted if no longer required");
 	}
 	else