Merge pull request 'make lmdb's map_size configurable (fix #628)' (#630) from configurable-map-size into main

Reviewed-on: Deuxfleurs/garage#630

Cargo.lock

@@ -1421,6 +1421,7 @@ dependencies = [
  "async-trait",
  "blake2",
  "bytes",
+ "bytesize",
  "chrono",
  "digest",
  "err-derive",

Cargo.nix

@@ -33,7 +33,7 @@ args@{
   ignoreLockHash,
 }:
 let
-  nixifiedLockHash = "b958f9aca0ee3fb1f7b52b15508132d0a96480a7f43f83e0da6609c0fe1812ef";
+  nixifiedLockHash = "3e3f41f614ab470ecb4b06c670cd6a84c443d799d01f1d48f1d251872099c468";
   workspaceSrc = if args.workspaceSrc == null then ./. else args.workspaceSrc;
   currentLockHash = builtins.hashFile "sha256" (workspaceSrc + /Cargo.lock);
   lockHashIgnored = if ignoreLockHash
@@ -2014,6 +2014,7 @@ in
       async_trait = (buildRustPackages."registry+https://github.com/rust-lang/crates.io-index".async-trait."0.1.73" { profileName = "__noProfile"; }).out;
       blake2 = (rustPackages."registry+https://github.com/rust-lang/crates.io-index".blake2."0.10.6" { inherit profileName; }).out;
       bytes = (rustPackages."registry+https://github.com/rust-lang/crates.io-index".bytes."1.4.0" { inherit profileName; }).out;
+      bytesize = (rustPackages."registry+https://github.com/rust-lang/crates.io-index".bytesize."1.3.0" { inherit profileName; }).out;
       chrono = (rustPackages."registry+https://github.com/rust-lang/crates.io-index".chrono."0.4.26" { inherit profileName; }).out;
       digest = (rustPackages."registry+https://github.com/rust-lang/crates.io-index".digest."0.10.7" { inherit profileName; }).out;
       err_derive = (buildRustPackages."registry+https://github.com/rust-lang/crates.io-index".err-derive."0.3.1" { profileName = "__noProfile"; }).out;

doc/book/reference-manual/configuration.md

@@ -15,8 +15,9 @@ db_engine = "lmdb"
 
 block_size = 1048576
 
-sled_cache_capacity = 134217728
+sled_cache_capacity = "128MiB"
 sled_flush_every_ms = 2000
+lmdb_map_size = "1T"
 
 replication_mode = "3"
 
@@ -133,8 +134,8 @@ and not just the path to the metadata directory.
 ### `block_size`
 
 Garage splits stored objects in consecutive chunks of size `block_size`
-(except the last one which might be smaller). The default size is 1MB and
-should work in most cases. We recommend increasing it to e.g. 10MB if
+(except the last one which might be smaller). The default size is 1MiB and
+should work in most cases. We recommend increasing it to e.g. 10MiB if
 you are using Garage to store large files and have fast network connections
 between all nodes (e.g. 1gbps).
 
@@ -160,6 +161,14 @@ Increase this if sled is thrashing your SSD, at the risk of losing more data in
 of a power outage (though this should not matter much as data is replicated on other
 nodes). The default value, 2000ms, should be appropriate for most use cases.
 
+### `lmdb_map_size`
+
+This parameters can be used to set the map size used by LMDB,
+which is the size of the virtual memory region used for mapping the database file.
+The value of this parameter is the maximum size the metadata database can take.
+This value is not bound by the physical RAM size of the machine running Garage.
+If not specified, it defaults to 1GiB on 32-bit machines and 1TiB on 64-bit machines.
+
 ### `replication_mode`
 
 Garage supports the following replication modes:

src/model/garage.rs

@@ -95,7 +95,7 @@ impl Garage {
 				info!("Opening Sled database at: {}", db_path.display());
 				let db = db::sled_adapter::sled::Config::default()
 					.path(&db_path)
-					.cache_capacity(config.sled_cache_capacity)
+					.cache_capacity(config.sled_cache_capacity as u64)
 					.flush_every_ms(Some(config.sled_flush_every_ms))
 					.open()
 					.ok_or_message("Unable to open sled DB")?;
@@ -125,7 +125,10 @@ impl Garage {
 				info!("Opening LMDB database at: {}", db_path.display());
 				std::fs::create_dir_all(&db_path)
 					.ok_or_message("Unable to create LMDB data directory")?;
-				let map_size = garage_db::lmdb_adapter::recommended_map_size();
+				let map_size = match config.lmdb_map_size {
+					v if v == usize::default() => garage_db::lmdb_adapter::recommended_map_size(),
+					v => v - (v % 4096),
+				};
 
 				use db::lmdb_adapter::heed;
 				let mut env_builder = heed::EnvOpenOptions::new();
@@ -142,6 +145,7 @@ impl Garage {
 							"OutOfMemory error while trying to open LMDB database. This can happen \
 							if your operating system is not allowing you to use sufficient virtual \
 							memory address space. Please check that no limit is set (ulimit -v). \
+							You may also try to set a smaller `lmdb_map_size` configuration parameter. \
 							On 32-bit machines, you should probably switch to another database engine.".into()))
 					}
 					x => x.ok_or_message("Unable to open LMDB DB")?,

src/util/Cargo.toml

@@ -20,6 +20,7 @@ arc-swap = "1.0"
 async-trait = "0.1"
 blake2 = "0.10"
 bytes = "1.0"
+bytesize = "1.2"
 digest = "0.10"
 err-derive = "0.3"
 hexdump = "0.1"

src/util/config.rs

@@ -1,4 +1,5 @@
 //! Contains type and functions related to Garage configuration file
+use std::convert::TryFrom;
 use std::io::Read;
 use std::net::SocketAddr;
 use std::path::PathBuf;
@@ -16,7 +17,10 @@ pub struct Config {
 	pub data_dir: PathBuf,
 
 	/// Size of data blocks to save to disk
-	#[serde(default = "default_block_size")]
+	#[serde(
+		deserialize_with = "deserialize_capacity",
+		default = "default_block_size"
+	)]
 	pub block_size: usize,
 
 	/// Replication mode. Supported values:
@@ -66,12 +70,19 @@ pub struct Config {
 	pub db_engine: String,
 
 	/// Sled cache size, in bytes
-	#[serde(default = "default_sled_cache_capacity")]
-	pub sled_cache_capacity: u64,
+	#[serde(
+		deserialize_with = "deserialize_capacity",
+		default = "default_sled_cache_capacity"
+	)]
+	pub sled_cache_capacity: usize,
 	/// Sled flush interval in milliseconds
 	#[serde(default = "default_sled_flush_every_ms")]
 	pub sled_flush_every_ms: u64,
 
+	/// LMDB map size
+	#[serde(deserialize_with = "deserialize_capacity", default)]
+	pub lmdb_map_size: usize,
+
 	// -- APIs
 	/// Configuration for S3 api
 	pub s3_api: S3ApiConfig,
@@ -186,7 +197,7 @@ fn default_db_engine() -> String {
 	"sled".into()
 }
 
-fn default_sled_cache_capacity() -> u64 {
+fn default_sled_cache_capacity() -> usize {
 	128 * 1024 * 1024
 }
 fn default_sled_flush_every_ms() -> u64 {
@@ -266,8 +277,6 @@ fn deserialize_compression<'de, D>(deserializer: D) -> Result<Option<i32>, D::Er
 where
 	D: de::Deserializer<'de>,
 {
-	use std::convert::TryFrom;
-
 	struct OptionVisitor;
 
 	impl<'de> serde::de::Visitor<'de> for OptionVisitor {
@@ -312,6 +321,50 @@ where
 	deserializer.deserialize_any(OptionVisitor)
 }
 
+fn deserialize_capacity<'de, D>(deserializer: D) -> Result<usize, D::Error>
+where
+	D: de::Deserializer<'de>,
+{
+	struct CapacityVisitor;
+
+	impl<'de> serde::de::Visitor<'de> for CapacityVisitor {
+		type Value = usize;
+		fn expecting(&self, formatter: &mut std::fmt::Formatter) -> std::fmt::Result {
+			formatter.write_str("int or '<capacity>'")
+		}
+
+		fn visit_str<E>(self, value: &str) -> Result<Self::Value, E>
+		where
+			E: de::Error,
+		{
+			value
+				.parse::<bytesize::ByteSize>()
+				.map(|x| x.as_u64())
+				.map_err(|e| E::custom(format!("invalid capacity value: {}", e)))
+				.and_then(|v| {
+					usize::try_from(v)
+						.map_err(|_| E::custom("capacity value out of bound".to_owned()))
+				})
+		}
+
+		fn visit_i64<E>(self, v: i64) -> Result<Self::Value, E>
+		where
+			E: de::Error,
+		{
+			usize::try_from(v).map_err(|_| E::custom("capacity value out of bound".to_owned()))
+		}
+
+		fn visit_u64<E>(self, v: u64) -> Result<Self::Value, E>
+		where
+			E: de::Error,
+		{
+			usize::try_from(v).map_err(|_| E::custom("capacity value out of bound".to_owned()))
+		}
+	}
+
+	deserializer.deserialize_any(CapacityVisitor)
+}
+
 #[cfg(test)]
 mod tests {
 	use crate::error::Error;