Implement a RocksDB backend for benchmarking

Reviewed-on: Deuxfleurs/garage#896
Reviewed-by: maximilien <me@mricher.fr>

.woodpecker/debug.yaml

@@ -37,6 +37,8 @@ steps:
       - GARAGE_TEST_INTEGRATION_DB_ENGINE=lmdb ./result/bin/integration-* || (cat tmp-garage-integration/stderr.log; false)
       - nix-shell --attr ci --run "killall -9 garage" || true
       - GARAGE_TEST_INTEGRATION_DB_ENGINE=sqlite ./result/bin/integration-* || (cat tmp-garage-integration/stderr.log; false)
+      - nix-shell --attr ci --run "killall -9 garage" || true
+      - GARAGE_TEST_INTEGRATION_DB_ENGINE=rocksdb ./result/bin/integration-* || (cat tmp-garage-integration/stderr.log; false)
       - rm result
       - rm -rv tmp-garage-integration
 

Cargo.toml

@@ -61,6 +61,7 @@ md-5 = "0.10"
 mktemp = "0.5"
 nix = { version = "0.27", default-features = false, features = ["fs"] }
 nom = "7.1"
+num_cpus = "1.0"
 parse_duration = "2.1"
 pin-project = "1.0.12"
 pnet_datalink = "0.34"
@@ -85,6 +86,7 @@ heed = { version = "0.11", default-features = false, features = ["lmdb"] }
 rusqlite = "0.31.0"
 r2d2 = "0.8"
 r2d2_sqlite = "0.24"
+rocksdb = { version = "0.22", features = ["multi-threaded-cf"] }
 
 async-compression = { version = "0.4", features = ["tokio", "zstd"] }
 zstd = { version = "0.13", default-features = false }

doc/book/build/python.md

@@ -23,7 +23,7 @@ client = minio.Minio(
   "GKyourapikey",
   "abcd[...]1234",
   # Force the region, this is specific to garage
-  region="region",
+  region="garage",
 )
 ```
 

doc/book/connect/apps/index.md

@@ -335,6 +335,7 @@ From the [official Mastodon documentation](https://docs.joinmastodon.org/admin/t
 
 ```bash
 $ RAILS_ENV=production bin/tootctl media remove --days 3
+$ RAILS_ENV=production bin/tootctl media remove --days 15 --prune-profiles
 $ RAILS_ENV=production bin/tootctl media remove-orphans
 $ RAILS_ENV=production bin/tootctl preview_cards remove --days 15
 ```
@@ -353,8 +354,6 @@ Imports:	1.7 KB
 Settings:	0 Bytes
 ```
 
-Unfortunately, [old avatars and headers cannot currently be cleaned up](https://github.com/mastodon/mastodon/issues/9567).
-
 ### Migrating your data
 
 Data migration should be done with an efficient S3 client.

doc/book/design/goals.md

@@ -50,3 +50,20 @@ locations. They use Garage themselves for the following tasks:
 
 The Deuxfleurs Garage cluster is a multi-site cluster currently composed of
 9 nodes in 3 physical locations.
+
+### Triplebit
+
+[Triplebit](https://www.triplebit.org) is a non-profit hosting provider and
+ISP focused on improving access to privacy-related services. They use
+Garage themselves for the following tasks:
+
+- Hosting of their homepage, [privacyguides.org](https://www.privacyguides.org/), and various other static sites
+
+- As a Mastodon object storage backend for [mstdn.party](https://mstdn.party/) and [mstdn.plus](https://mstdn.plus/)
+
+- As a PeerTube storage backend for [neat.tube](https://neat.tube/)
+
+- As a [Matrix media backend](https://github.com/matrix-org/synapse-s3-storage-provider)
+
+Triplebit's Garage cluster is a multi-site cluster currently composed of
+10 nodes in 3 physical locations.

script/helm/garage/templates/workload.yaml

@@ -76,6 +76,9 @@ spec:
             - name: etc
               mountPath: /etc/garage.toml
               subPath: garage.toml
+          {{- with .Values.extraVolumeMounts }}
+            {{- toYaml . | nindent 12 }}
+          {{- end }}
           # TODO
           # livenessProbe:
           #   httpGet:
@@ -110,6 +113,9 @@ spec:
         - name: data
           emptyDir: {}
         {{- end }}
+        {{- with .Values.extraVolumes }}
+          {{- toYaml . | nindent 8 }}
+        {{- end }}
       {{- with .Values.nodeSelector }}
       nodeSelector:
         {{- toYaml . | nindent 8 }}

script/helm/garage/values.yaml

@@ -218,6 +218,10 @@ affinity: {}
 
 environment: {}
 
+extraVolumes: {}
+
+extraVolumeMounts: {}
+
 monitoring:
   metrics:
     # If true, a service for monitoring is created with a prometheus.io/scrape annotation

src/db/Cargo.toml

@@ -15,11 +15,14 @@ path = "lib.rs"
 err-derive.workspace = true
 hexdump.workspace = true
 tracing.workspace = true
+opentelemetry.workspace = true
 
 heed = { workspace = true, optional = true }
 rusqlite = { workspace = true, optional = true, features = ["backup"] }
 r2d2 = { workspace = true, optional = true }
 r2d2_sqlite = { workspace = true, optional = true }
+rocksdb = { workspace = true, optional = true }
+num_cpus = { workspace = true, optional = true }
 
 [dev-dependencies]
 mktemp.workspace = true
@@ -29,3 +32,4 @@ default = [ "lmdb", "sqlite" ]
 bundled-libs = [ "rusqlite?/bundled" ]
 lmdb = [ "heed" ]
 sqlite = [ "rusqlite", "r2d2", "r2d2_sqlite" ]
+rocksdb = [ "dep:rocksdb", "dep:num_cpus" ]

src/db/lib.rs

@@ -5,6 +5,10 @@ extern crate tracing;
 pub mod lmdb_adapter;
 #[cfg(feature = "sqlite")]
 pub mod sqlite_adapter;
+#[cfg(feature = "rocksdb")]
+pub mod rocksdb_adapter;
+#[cfg(feature = "rocksdb")]
+pub mod metric_proxy;
 
 pub mod open;
 

src/db/metric_proxy.rs

@@ -0,0 +1,217 @@
+use std::path::PathBuf;
+use std::sync::Arc;
+use std::time::Instant;
+
+use crate::rocksdb_adapter::RocksDb;
+use crate::{
+	Bound, Db, IDb, ITx, ITxFn, OnCommit, Result, TxFnResult, TxOpResult, TxResult, TxValueIter,
+	Value, ValueIter,
+};
+use opentelemetry::{
+	global,
+	metrics::{Unit, ValueRecorder},
+	KeyValue,
+};
+
+pub struct MetricDbProxy {
+	//@FIXME Replace with a template
+	db: RocksDb,
+	op: ValueRecorder<f64>,
+}
+
+impl MetricDbProxy {
+	pub fn init(db: RocksDb) -> Db {
+		let meter = global::meter("garage/db");
+		let s = Self {
+			db,
+			op: meter
+				.f64_value_recorder("db.op")
+				.with_description("Duration and amount of operations on the local metadata engine")
+				.with_unit(Unit::new("ms"))
+				.init(),
+		};
+		Db(Arc::new(s))
+	}
+
+	fn instrument<T>(
+		&self,
+		fx: impl FnOnce() -> T,
+		op: &'static str,
+		cat: &'static str,
+		tx: &'static str,
+	) -> T {
+		let metric_tags = [
+			KeyValue::new("op", op),
+			KeyValue::new("cat", cat),
+			KeyValue::new("tx", tx),
+		];
+
+		let request_start = Instant::now();
+		let res = fx();
+		let delay_nanos = Instant::now()
+			.saturating_duration_since(request_start)
+			.as_nanos();
+		let delay_millis: f64 = delay_nanos as f64 / 1_000_000f64;
+		self.op.record(delay_millis, &metric_tags);
+
+		res
+	}
+}
+
+impl IDb for MetricDbProxy {
+	fn engine(&self) -> String {
+		format!("Metric Proxy on {}", self.db.engine())
+	}
+
+	fn open_tree(&self, name: &str) -> Result<usize> {
+		self.instrument(|| self.db.open_tree(name), "open_tree", "control", "no")
+	}
+
+	fn list_trees(&self) -> Result<Vec<String>> {
+		self.instrument(|| self.db.list_trees(), "list_trees", "control", "no")
+	}
+
+	fn snapshot(&self, to: &PathBuf) -> Result<()> {
+		self.instrument(|| self.db.snapshot(to), "snapshot", "control", "no")
+	}
+
+	// ---
+
+	fn get(&self, tree: usize, key: &[u8]) -> Result<Option<Value>> {
+		self.instrument(|| self.db.get(tree, key), "get", "data", "no")
+	}
+
+	fn len(&self, tree: usize) -> Result<usize> {
+		self.instrument(|| self.db.len(tree), "len", "data", "no")
+	}
+
+	fn insert(&self, tree: usize, key: &[u8], value: &[u8]) -> Result<()> {
+		self.instrument(|| self.db.insert(tree, key, value), "insert", "data", "no")
+	}
+
+	fn remove(&self, tree: usize, key: &[u8]) -> Result<()> {
+		self.instrument(|| self.db.remove(tree, key), "remove", "data", "no")
+	}
+
+	fn clear(&self, tree: usize) -> Result<()> {
+		self.instrument(|| self.db.clear(tree), "clear", "data", "no")
+	}
+
+	fn iter(&self, tree: usize) -> Result<ValueIter<'_>> {
+		self.instrument(|| self.db.iter(tree), "iter", "data", "no")
+	}
+
+	fn iter_rev(&self, tree: usize) -> Result<ValueIter<'_>> {
+		self.instrument(|| self.db.iter_rev(tree), "iter_rev", "data", "no")
+	}
+
+	fn range<'r>(
+		&self,
+		tree: usize,
+		low: Bound<&'r [u8]>,
+		high: Bound<&'r [u8]>,
+	) -> Result<ValueIter<'_>> {
+		self.instrument(|| self.db.range(tree, low, high), "range", "data", "no")
+	}
+
+	fn range_rev<'r>(
+		&self,
+		tree: usize,
+		low: Bound<&'r [u8]>,
+		high: Bound<&'r [u8]>,
+	) -> Result<ValueIter<'_>> {
+		self.instrument(
+			|| self.db.range_rev(tree, low, high),
+			"range_rev",
+			"data",
+			"no",
+		)
+	}
+
+	// ----
+
+	fn transaction(&self, f: &dyn ITxFn) -> TxResult<OnCommit, ()> {
+		self.instrument(
+			|| self.db.transaction(&MetricITxFnProxy { f, metrics: self }),
+			"transaction",
+			"control",
+			"yes",
+		)
+	}
+}
+
+struct MetricITxFnProxy<'a> {
+	f: &'a dyn ITxFn,
+	metrics: &'a MetricDbProxy,
+}
+impl<'a> ITxFn for MetricITxFnProxy<'a> {
+	fn try_on(&self, tx: &mut dyn ITx) -> TxFnResult {
+		self.f.try_on(&mut MetricTxProxy {
+			tx,
+			metrics: self.metrics,
+		})
+	}
+}
+
+struct MetricTxProxy<'a> {
+	tx: &'a mut dyn ITx,
+	metrics: &'a MetricDbProxy,
+}
+impl<'a> ITx for MetricTxProxy<'a> {
+	fn get(&self, tree: usize, key: &[u8]) -> TxOpResult<Option<Value>> {
+		self.metrics
+			.instrument(|| self.tx.get(tree, key), "get", "data", "yes")
+	}
+
+	fn len(&self, tree: usize) -> TxOpResult<usize> {
+		self.metrics
+			.instrument(|| self.tx.len(tree), "len", "data", "yes")
+	}
+
+	fn insert(&mut self, tree: usize, key: &[u8], value: &[u8]) -> TxOpResult<()> {
+		self.metrics
+			.instrument(|| self.tx.insert(tree, key, value), "insert", "data", "yes")
+	}
+
+	fn remove(&mut self, tree: usize, key: &[u8]) -> TxOpResult<()> {
+		self.metrics
+			.instrument(|| self.tx.remove(tree, key), "remove", "data", "yes")
+	}
+
+	fn clear(&mut self, tree: usize) -> TxOpResult<()> {
+		self.metrics
+			.instrument(|| self.tx.clear(tree), "clear", "data", "yes")
+	}
+
+	fn iter(&self, tree: usize) -> TxOpResult<TxValueIter<'_>> {
+		self.metrics
+			.instrument(|| self.tx.iter(tree), "iter", "data", "yes")
+	}
+	fn iter_rev(&self, tree: usize) -> TxOpResult<TxValueIter<'_>> {
+		self.metrics
+			.instrument(|| self.tx.iter_rev(tree), "iter_rev", "data", "yes")
+	}
+	fn range<'r>(
+		&self,
+		tree: usize,
+		low: Bound<&'r [u8]>,
+		high: Bound<&'r [u8]>,
+	) -> TxOpResult<TxValueIter<'_>> {
+		self.metrics
+			.instrument(|| self.tx.range(tree, low, high), "range", "data", "yes")
+	}
+
+	fn range_rev<'r>(
+		&self,
+		tree: usize,
+		low: Bound<&'r [u8]>,
+		high: Bound<&'r [u8]>,
+	) -> TxOpResult<TxValueIter<'_>> {
+		self.metrics.instrument(
+			|| self.tx.range_rev(tree, low, high),
+			"range_rev",
+			"data",
+			"yes",
+		)
+	}
+}

src/db/open.rs

@@ -11,6 +11,8 @@ use crate::{Db, Error, Result};
 pub enum Engine {
 	Lmdb,
 	Sqlite,
+    RocksDb,
+    RocksDbWithMetrics,
 }
 
 impl Engine {
@@ -19,6 +21,8 @@ impl Engine {
 		match self {
 			Self::Lmdb => "lmdb",
 			Self::Sqlite => "sqlite",
+            Self::RocksDb => "rocksdb",
+            Self::RocksDbWithMetrics => "rocksdb-with-metrics",
 		}
 	}
 }
@@ -36,6 +40,8 @@ impl std::str::FromStr for Engine {
 		match text {
 			"lmdb" | "heed" => Ok(Self::Lmdb),
 			"sqlite" | "sqlite3" | "rusqlite" => Ok(Self::Sqlite),
+			"rocksdb" => Ok(Self::RocksDb),
+			"rocksdb-with-metrics" => Ok(Self::RocksDbWithMetrics),
 			"sled" => Err(Error("Sled is no longer supported as a database engine. Converting your old metadata db can be done using an older Garage binary (e.g. v0.9.4).".into())),
 			kind => Err(Error(
 				format!(
@@ -114,6 +120,31 @@ pub fn open_db(path: &PathBuf, engine: Engine, opt: &OpenOpt) -> Result<Db> {
 			}
 		}
 
+		// ---- RocksDB ----
+		#[cfg(feature = "rocksdb")]
+		Engine::RocksDb => {
+			info!("Opening RocksDb database at: {}", path.display());
+            let mut options = rocksdb::Options::default();
+            options.increase_parallelism(num_cpus::get() as i32);
+            options.create_if_missing(true);
+            options.set_compression_type(rocksdb::DBCompressionType::Zstd);
+            let txn_options = rocksdb::TransactionDBOptions::default();
+			Ok(crate::rocksdb_adapter::RocksDb::init(options, txn_options, path))
+		}
+
+		// ---- RocksDB ----
+		#[cfg(feature = "rocksdb")]
+		Engine::RocksDbWithMetrics => {
+			info!("Opening RocksDb database at: {}", path.display());
+            let mut options = rocksdb::Options::default();
+            options.increase_parallelism(num_cpus::get() as i32);
+            options.create_if_missing(true);
+            options.set_compression_type(rocksdb::DBCompressionType::Zstd);
+            let txn_options = rocksdb::TransactionDBOptions::default();
+            let db = crate::rocksdb_adapter::RocksDb::new(options, txn_options, path);
+			Ok(crate::metric_proxy::MetricDbProxy::init(db))
+		}
+
 		// Pattern is unreachable when all supported DB engines are compiled into binary. The allow
 		// attribute is added so that we won't have to change this match in case stop building
 		// support for one or more engines by default.

src/db/rocksdb_adapter.rs

@@ -0,0 +1,322 @@
+use std::path::PathBuf;
+use std::sync::{Arc, RwLock};
+use std::collections::HashMap;
+use core::ops::Bound;
+
+use rocksdb::{self as rks, BoundColumnFamily, Direction, IteratorMode, MultiThreaded, Options, Transaction, TransactionDB, TransactionDBOptions};
+
+use crate::{
+	Db, Error, IDb, ITx, ITxFn, OnCommit, Result, TxError, TxFnResult, TxOpError, TxOpResult,
+	TxResult, TxValueIter, Value, ValueIter,
+};
+
+pub struct RocksDb {
+    db: TransactionDB<MultiThreaded>,
+	column_families: RwLock<(Vec<String>, HashMap<String, usize>)>,
+}
+
+impl RocksDb {
+    pub fn init(options: Options, txn_options: TransactionDBOptions, path: &PathBuf) -> Db {
+        Db(Arc::new(Self::new(options, txn_options, path)))
+    }
+
+    pub fn new(options: Options, txn_options: TransactionDBOptions, path: &PathBuf) -> RocksDb {
+        let db = TransactionDB::open(&options, &txn_options, path).unwrap();
+        let existing_cf = TransactionDB::<MultiThreaded>::list_cf(&Options::default(), path).unwrap();
+        let existing_cf_map = existing_cf.iter().enumerate().map(|(i, n)| (n.clone(), i)).collect();
+
+        Self {
+            db,
+            column_families: RwLock::new((existing_cf, existing_cf_map)),
+        }
+    }
+
+    fn get_cf_handle(&self, tree: usize) -> Result<Arc<BoundColumnFamily>> {
+        let column_families = self.column_families.read().unwrap();
+        let name = column_families.0.get(tree);
+        name.map(|n| self.db.cf_handle(n)).flatten().ok_or(
+            Error("trying to acquire a handle on a non-existing column family".into())
+        )
+    }
+}
+
+impl IDb for RocksDb {
+    fn engine(&self) -> String {
+        "rocksdb".into()
+    }
+
+	fn open_tree(&self, name: &str) -> Result<usize> {
+        let mut column_families = self.column_families.write().unwrap();
+        let open_tree = column_families.1.get(name);
+
+        if let Some(i) = open_tree {
+            Ok(*i)
+        } else {
+            self.db.create_cf(name, &Options::default())?;
+            column_families.0.push(name.to_string());
+            let i = column_families.0.len() - 1;
+            column_families.1.insert(name.to_string(), i);
+            Ok(i)
+        }
+    }
+
+	fn list_trees(&self) -> Result<Vec<String>> {
+        Ok(self.column_families.read().unwrap().0.clone())
+    }
+
+	fn snapshot(&self, path: &PathBuf) -> Result<()> {
+        todo!("snapshots for RocksDB");
+    }
+
+	fn get(&self, tree: usize, key: &[u8]) -> Result<Option<Value>> {
+        let cf_handle = self.get_cf_handle(tree)?;
+        Ok(self.db.get_cf(&cf_handle, key)?)
+    }
+
+	fn len(&self, tree: usize) -> Result<usize> {
+        let cf_handle = self.get_cf_handle(tree)?;
+        Ok(self.db.iterator_cf(&cf_handle, IteratorMode::Start).count())
+    }
+
+	fn insert(&self, tree: usize, key: &[u8], value: &[u8]) -> Result<()> {
+        let cf_handle = self.get_cf_handle(tree)?;
+        Ok(self.db.put_cf(&cf_handle, key, value)?)
+    }
+
+	fn remove(&self, tree: usize, key: &[u8]) -> Result<()> {
+        let cf_handle = self.get_cf_handle(tree)?;
+        Ok(self.db.delete_cf(&cf_handle, key)?)
+    }
+
+	fn clear(&self, tree: usize) -> Result<()> {
+        let column_families = self.column_families.write().unwrap(); // locking against open_tree
+        let tree_name = column_families.0.get(tree).ok_or(
+            Error("trying to clear a non-existing column family".into())
+        )?;
+        self.db.drop_cf(tree_name)?;
+        self.db.create_cf(tree_name, &Options::default())?;
+        Ok(())
+    }
+
+	fn iter(&self, tree: usize) -> Result<ValueIter<'_>> {
+        let cf_handle = self.get_cf_handle(tree)?;
+        Ok(Box::new(
+            self.db.iterator_cf(&cf_handle, IteratorMode::Start)
+                .map(|r| r
+                     .map(|(k, v)| (k.into_vec(), v.into_vec()))
+                     .map_err(|e| e.into()))
+        ))
+    }
+
+	fn iter_rev(&self, tree: usize) -> Result<ValueIter<'_>> {
+        let cf_handle = self.get_cf_handle(tree)?;
+        Ok(Box::new(
+            self.db.iterator_cf(&cf_handle, IteratorMode::End)
+                .map(|r| r
+                     .map(|(k, v)| (k.into_vec(), v.into_vec()))
+                     .map_err(|e| e.into()))
+        ))
+    }
+
+	fn range<'r>(
+		&self,
+		tree: usize,
+		low: Bound<&'r [u8]>,
+		high: Bound<&'r [u8]>,
+	) -> Result<ValueIter<'_>> {
+        let cf_handle = self.get_cf_handle(tree)?;
+        let start_mode = match low {
+            Bound::Included(i) | Bound::Excluded(i) => IteratorMode::From(i, Direction::Forward),
+            Bound::Unbounded => IteratorMode::Start,
+        };
+        let base_iterator = self.db.iterator_cf(&cf_handle, start_mode)
+            .map(|r| r
+                 .map(|(k, v)| (k.into_vec(), v.into_vec()))
+                 .map_err(|e| e.into()));
+
+        let stop_value = match high {
+            Bound::Included(i) | Bound::Excluded(i) => i.to_vec(),
+            Bound::Unbounded => return Ok(Box::new(base_iterator)),
+        };
+
+        Ok(Box::new(
+            base_iterator
+                .take_while(move |r| r.as_ref().map(|(k, _v)| *k < stop_value).unwrap_or(false))
+        ))
+    }
+
+	fn range_rev<'r>(
+		&self,
+		tree: usize,
+		low: Bound<&'r [u8]>,
+		high: Bound<&'r [u8]>,
+	) -> Result<ValueIter<'_>> {
+        let cf_handle = self.get_cf_handle(tree)?;
+        let start_mode = match high {
+            Bound::Included(i) | Bound::Excluded(i) => IteratorMode::From(i, Direction::Reverse),
+            Bound::Unbounded => IteratorMode::End,
+        };
+        let base_iterator = self.db.iterator_cf(&cf_handle, start_mode)
+            .map(|r| r
+                 .map(|(k, v)| (k.into_vec(), v.into_vec()))
+                 .map_err(|e| e.into()));
+
+        let stop_value = match low {
+            Bound::Included(i) | Bound::Excluded(i) => i.to_vec(),
+            Bound::Unbounded => return Ok(Box::new(base_iterator)),
+        };
+
+        Ok(Box::new(
+            base_iterator
+                .take_while(move |r| r.as_ref().map(|(k, _v)| *k >= stop_value).unwrap_or(false))
+        ))
+    }
+
+	fn transaction(&self, f: &dyn ITxFn) -> TxResult<OnCommit, ()> {
+        let txn = self.db.transaction();
+        let mut tx = RocksTx {
+            db: &self,
+            txn,
+        };
+
+        match f.try_on(&mut tx) {
+            TxFnResult::Ok(on_commit) => {
+				tx.txn.commit().map_err(Error::from).map_err(TxError::Db)?;
+				Ok(on_commit)
+			}
+			TxFnResult::Abort => {
+				tx.txn.rollback().map_err(Error::from).map_err(TxError::Db)?;
+				Err(TxError::Abort(()))
+			}
+			TxFnResult::DbErr => {
+				tx.txn.rollback().map_err(Error::from).map_err(TxError::Db)?;
+				Err(TxError::Db(Error(
+					"(this message will be discarded)".into(),
+				)))
+			}
+        }
+    }
+}
+
+pub struct RocksTx<'a> {
+    db: &'a RocksDb,
+    txn: Transaction<'a, TransactionDB<MultiThreaded>>,
+}
+
+impl<'a> ITx for RocksTx<'a> {
+	fn get(&self, tree: usize, key: &[u8]) -> TxOpResult<Option<Value>> {
+        let cf_handle = self.db.get_cf_handle(tree)?;
+        Ok(self.txn.get_cf(&cf_handle, key)?)
+    }
+
+	fn len(&self, tree: usize) -> TxOpResult<usize> {
+        let cf_handle = self.db.get_cf_handle(tree)?;
+        Ok(self.txn.iterator_cf(&cf_handle, IteratorMode::Start).count())
+    }
+
+	fn insert(&mut self, tree: usize, key: &[u8], value: &[u8]) -> TxOpResult<()> {
+        let cf_handle = self.db.get_cf_handle(tree)?;
+        Ok(self.txn.put_cf(&cf_handle, key, value)?)
+    }
+
+	fn remove(&mut self, tree: usize, key: &[u8]) -> TxOpResult<()> {
+        let cf_handle = self.db.get_cf_handle(tree)?;
+        Ok(self.txn.delete_cf(&cf_handle, key)?)
+    }
+
+	fn clear(&mut self, _tree: usize) -> TxOpResult<()> {
+        unimplemented!("transactional column family clear not supported in RocksDB")
+    }
+
+	fn iter(&self, tree: usize) -> TxOpResult<TxValueIter<'_>> {
+        let cf_handle = self.db.get_cf_handle(tree)?;
+        Ok(Box::new(
+            self.txn.iterator_cf(&cf_handle, IteratorMode::Start)
+                .map(|r| r
+                     .map(|(k, v)| (k.into_vec(), v.into_vec()))
+                     .map_err(|e| e.into()))
+        ))
+    }
+
+	fn iter_rev(&self, tree: usize) -> TxOpResult<TxValueIter<'_>> {
+        let cf_handle = self.db.get_cf_handle(tree)?;
+        Ok(Box::new(
+            self.txn.iterator_cf(&cf_handle, IteratorMode::End)
+                .map(|r| r
+                     .map(|(k, v)| (k.into_vec(), v.into_vec()))
+                     .map_err(|e| e.into()))
+        ))
+    }
+
+	fn range<'r>(
+		&self,
+		tree: usize,
+		low: Bound<&'r [u8]>,
+		high: Bound<&'r [u8]>,
+	) -> TxOpResult<TxValueIter<'_>> {
+        let cf_handle = self.db.get_cf_handle(tree)?;
+        let start_mode = match low {
+            Bound::Included(i) | Bound::Excluded(i) => IteratorMode::From(i, Direction::Forward),
+            Bound::Unbounded => IteratorMode::Start,
+        };
+        let base_iterator = self.txn.iterator_cf(&cf_handle, start_mode)
+            .map(|r| r
+                 .map(|(k, v)| (k.into_vec(), v.into_vec()))
+                 .map_err(|e| e.into()));
+
+        let stop_value = match high {
+            Bound::Included(i) | Bound::Excluded(i) => i.to_vec(),
+            Bound::Unbounded => return Ok(Box::new(base_iterator)),
+        };
+
+        Ok(Box::new(
+            base_iterator
+                .take_while(move |r| r.as_ref().map(|(k, _v)| *k < stop_value).unwrap_or(false))
+        ))
+    }
+
+	fn range_rev<'r>(
+		&self,
+		tree: usize,
+		low: Bound<&'r [u8]>,
+		high: Bound<&'r [u8]>,
+	) -> TxOpResult<TxValueIter<'_>> {
+        let cf_handle = self.db.get_cf_handle(tree)?;
+        let start_mode = match high {
+            Bound::Included(i) | Bound::Excluded(i) => IteratorMode::From(i, Direction::Reverse),
+            Bound::Unbounded => IteratorMode::End,
+        };
+        let base_iterator = self.txn.iterator_cf(&cf_handle, start_mode)
+            .map(|r| r
+                 .map(|(k, v)| (k.into_vec(), v.into_vec()))
+                 .map_err(|e| e.into()));
+
+        let stop_value = match low {
+            Bound::Included(i) | Bound::Excluded(i) => i.to_vec(),
+            Bound::Unbounded => return Ok(Box::new(base_iterator)),
+        };
+
+        Ok(Box::new(
+            base_iterator
+                .take_while(move |r| r.as_ref().map(|(k, _v)| *k >= stop_value).unwrap_or(false))
+        ))
+    }
+}
+
+impl From<rks::Error> for Error {
+	fn from(e: rks::Error) -> Error {
+		Error(format!("RocksDB: {}", e).into())
+	}
+}
+
+impl From<rks::Error> for TxOpError {
+	fn from(e: rks::Error) -> TxOpError {
+		TxOpError(e.into())
+	}
+}
+
+impl From<Error> for TxOpError {
+	fn from(e: Error) -> TxOpError {
+		TxOpError(e.into())
+	}
+}

src/garage/Cargo.toml

@@ -89,6 +89,7 @@ k2v = [ "garage_util/k2v", "garage_api/k2v" ]
 # Database engines
 lmdb = [ "garage_model/lmdb" ]
 sqlite = [ "garage_model/sqlite" ]
+rocksdb = [ "garage_model/rocksdb" ]
 
 # Automatic registration and discovery via Consul API
 consul-discovery = [ "garage_rpc/consul-discovery" ]

src/model/Cargo.toml

@@ -47,3 +47,4 @@ default = [ "lmdb", "sqlite" ]
 k2v = [ "garage_util/k2v" ]
 lmdb = [ "garage_db/lmdb" ]
 sqlite = [ "garage_db/sqlite" ]
+rocksdb = [ "garage_db/rocksdb" ]

src/model/garage.rs

@@ -124,6 +124,9 @@ impl Garage {
 			db::Engine::Lmdb => {
 				db_path.push("db.lmdb");
 			}
+			db::Engine::RocksDb | db::Engine::RocksDbWithMetrics => {
+				db_path.push("db.rocksdb");
+			}
 		}
 		let db_opt = db::OpenOpt {
 			fsync: config.metadata_fsync,
@@ -141,7 +144,7 @@ impl Garage {
 		)?)
 		.ok()
 		.and_then(|x| NetworkKey::from_slice(&x))
-		.ok_or_message("Invalid RPC secret key: expected 32 bits of entropy, please check the documentation for requirements")?;
+		.ok_or_message("Invalid RPC secret key: expected 32 bytes of random hex, please check the documentation for requirements")?;
 
 		let (replication_factor, consistency_mode) = parse_replication_mode(&config)?;