Merge pull request 'improvements to CLI and new debug features' (#448) from cli-improvements into main

Reviewed-on: Deuxfleurs/garage#448

src/block/manager.rs

@@ -90,6 +90,15 @@ pub struct BlockManager {
 	tx_scrub_command: mpsc::Sender<ScrubWorkerCommand>,
 }
 
+#[derive(Serialize, Deserialize, Clone, Debug)]
+pub struct BlockResyncErrorInfo {
+	pub hash: Hash,
+	pub refcount: u64,
+	pub error_count: u64,
+	pub last_try: u64,
+	pub next_try: u64,
+}
+
 // This custom struct contains functions that must only be ran
 // when the lock is held. We ensure that it is the case by storing
 // it INSIDE a Mutex.
@@ -114,7 +123,8 @@ impl BlockManager {
 			.netapp
 			.endpoint("garage_block/manager.rs/Rpc".to_string());
 
-		let metrics = BlockManagerMetrics::new(resync.queue.clone(), resync.errors.clone());
+		let metrics =
+			BlockManagerMetrics::new(rc.rc.clone(), resync.queue.clone(), resync.errors.clone());
 
 		let (scrub_tx, scrub_rx) = mpsc::channel(1);
 
@@ -309,11 +319,41 @@ impl BlockManager {
 		Ok(self.rc.rc.len()?)
 	}
 
+	/// Get number of items in the refcount table
+	pub fn rc_fast_len(&self) -> Result<Option<usize>, Error> {
+		Ok(self.rc.rc.fast_len()?)
+	}
+
 	/// Send command to start/stop/manager scrub worker
 	pub async fn send_scrub_command(&self, cmd: ScrubWorkerCommand) {
 		let _ = self.tx_scrub_command.send(cmd).await;
 	}
 
+	/// Get the reference count of a block
+	pub fn get_block_rc(&self, hash: &Hash) -> Result<u64, Error> {
+		Ok(self.rc.get_block_rc(hash)?.as_u64())
+	}
+
+	/// List all resync errors
+	pub fn list_resync_errors(&self) -> Result<Vec<BlockResyncErrorInfo>, Error> {
+		let mut blocks = Vec::with_capacity(self.resync.errors.len());
+		for ent in self.resync.errors.iter()? {
+			let (hash, cnt) = ent?;
+			let cnt = ErrorCounter::decode(&cnt);
+			blocks.push(BlockResyncErrorInfo {
+				hash: Hash::try_from(&hash).unwrap(),
+				refcount: 0,
+				error_count: cnt.errors,
+				last_try: cnt.last_try,
+				next_try: cnt.next_try(),
+			});
+		}
+		for block in blocks.iter_mut() {
+			block.refcount = self.get_block_rc(&block.hash)?;
+		}
+		Ok(blocks)
+	}
+
 	//// ----- Managing the reference counter ----
 
 	/// Increment the number of time a block is used, putting it to resynchronization if it is

src/block/metrics.rs

@@ -1,9 +1,11 @@
 use opentelemetry::{global, metrics::*};
 
+use garage_db as db;
 use garage_db::counted_tree_hack::CountedTree;
 
 /// TableMetrics reference all counter used for metrics
 pub struct BlockManagerMetrics {
+	pub(crate) _rc_size: ValueObserver<u64>,
 	pub(crate) _resync_queue_len: ValueObserver<u64>,
 	pub(crate) _resync_errored_blocks: ValueObserver<u64>,
 
@@ -23,9 +25,17 @@ pub struct BlockManagerMetrics {
 }
 
 impl BlockManagerMetrics {
-	pub fn new(resync_queue: CountedTree, resync_errors: CountedTree) -> Self {
+	pub fn new(rc_tree: db::Tree, resync_queue: CountedTree, resync_errors: CountedTree) -> Self {
 		let meter = global::meter("garage_model/block");
 		Self {
+			_rc_size: meter
+				.u64_value_observer("block.rc_size", move |observer| {
+					if let Ok(Some(v)) = rc_tree.fast_len() {
+						observer.observe(v as u64, &[])
+					}
+				})
+				.with_description("Number of blocks known to the reference counter")
+				.init(),
 			_resync_queue_len: meter
 				.u64_value_observer("block.resync_queue_length", move |observer| {
 					observer.observe(resync_queue.len() as u64, &[])

src/block/rc.rs

@@ -169,4 +169,11 @@ impl RcEntry {
 	pub(crate) fn is_needed(&self) -> bool {
 		!self.is_deletable()
 	}
+
+	pub(crate) fn as_u64(&self) -> u64 {
+		match self {
+			RcEntry::Present { count } => *count,
+			_ => 0,
+		}
+	}
 }

src/block/repair.rs

@@ -53,7 +53,7 @@ impl Worker for RepairWorker {
 		"Block repair worker".into()
 	}
 
-	fn info(&self) -> Option<String> {
+	fn status(&self) -> WorkerStatus {
 		match self.block_iter.as_ref() {
 			None => {
 				let idx_bytes = self
@@ -66,9 +66,20 @@ impl Worker for RepairWorker {
 				} else {
 					idx_bytes
 				};
-				Some(format!("Phase 1: {}", hex::encode(idx_bytes)))
+				WorkerStatus {
+					progress: Some("0.00%".into()),
+					freeform: vec![format!(
+						"Currently in phase 1, iterator position: {}",
+						hex::encode(idx_bytes)
+					)],
+					..Default::default()
 				}
-			Some(bi) => Some(format!("Phase 2: {:.2}% done", bi.progress() * 100.)),
+			}
+			Some(bi) => WorkerStatus {
+				progress: Some(format!("{:.2}%", bi.progress() * 100.)),
+				freeform: vec!["Currently in phase 2".into()],
+				..Default::default()
+			},
 		}
 	}
 
@@ -271,29 +282,28 @@ impl Worker for ScrubWorker {
 		"Block scrub worker".into()
 	}
 
-	fn info(&self) -> Option<String> {
+	fn status(&self) -> WorkerStatus {
-		let s = match &self.work {
+		let mut s = WorkerStatus {
-			ScrubWorkerState::Running(bsi) => format!(
+			persistent_errors: Some(self.persisted.corruptions_detected),
-				"{:.2}% done (tranquility = {})",
+			tranquility: Some(self.persisted.tranquility),
-				bsi.progress() * 100.,
+			..Default::default()
-				self.persisted.tranquility
-			),
-			ScrubWorkerState::Paused(bsi, rt) => {
-				format!(
-					"Paused, {:.2}% done, resumes at {}",
-					bsi.progress() * 100.,
-					msec_to_rfc3339(*rt)
-				)
-			}
-			ScrubWorkerState::Finished => format!(
-				"Last completed scrub: {}",
-				msec_to_rfc3339(self.persisted.time_last_complete_scrub)
-			),
 		};
-		Some(format!(
+		match &self.work {
-			"{} ; corruptions detected: {}",
+			ScrubWorkerState::Running(bsi) => {
-			s, self.persisted.corruptions_detected
+				s.progress = Some(format!("{:.2}%", bsi.progress() * 100.));
-		))
+			}
+			ScrubWorkerState::Paused(bsi, rt) => {
+				s.progress = Some(format!("{:.2}%", bsi.progress() * 100.));
+				s.freeform = vec![format!("Scrub paused, resumes at {}", msec_to_rfc3339(*rt))];
+			}
+			ScrubWorkerState::Finished => {
+				s.freeform = vec![format!(
+					"Last scrub completed at {}",
+					msec_to_rfc3339(self.persisted.time_last_complete_scrub)
+				)];
+			}
+		}
+		s
 	}
 
 	async fn work(&mut self, _must_exit: &mut watch::Receiver<bool>) -> Result<WorkerState, Error> {

src/block/resync.rs

@@ -123,6 +123,24 @@ impl BlockResyncManager {
 		Ok(self.errors.len())
 	}
 
+	/// Clear the error counter for a block and put it in queue immediately
+	pub fn clear_backoff(&self, hash: &Hash) -> Result<(), Error> {
+		let now = now_msec();
+		if let Some(ec) = self.errors.get(hash)? {
+			let mut ec = ErrorCounter::decode(&ec);
+			if ec.errors > 0 {
+				ec.last_try = now - ec.delay_msec();
+				self.errors.insert(hash, ec.encode())?;
+				self.put_to_resync_at(hash, now)?;
+				return Ok(());
+			}
+		}
+		Err(Error::Message(format!(
+			"Block {:?} was not in an errored state",
+			hash
+		)))
+	}
+
 	// ---- Resync loop ----
 
 	// This part manages a queue of blocks that need to be
@@ -257,7 +275,7 @@ impl BlockResyncManager {
 
 				if let Err(e) = &res {
 					manager.metrics.resync_error_counter.add(1);
-					warn!("Error when resyncing {:?}: {}", hash, e);
+					error!("Error when resyncing {:?}: {}", hash, e);
 
 					let err_counter = match self.errors.get(hash.as_slice())? {
 						Some(ec) => ErrorCounter::decode(&ec).add1(now + 1),
@@ -477,27 +495,22 @@ impl Worker for ResyncWorker {
 		format!("Block resync worker #{}", self.index + 1)
 	}
 
-	fn info(&self) -> Option<String> {
+	fn status(&self) -> WorkerStatus {
 		let persisted = self.manager.resync.persisted.load();
 
 		if self.index >= persisted.n_workers {
-			return Some("(unused)".into());
+			return WorkerStatus {
+				freeform: vec!["This worker is currently disabled".into()],
+				..Default::default()
+			};
 		}
 
-		let mut ret = vec![];
+		WorkerStatus {
-		ret.push(format!("tranquility = {}", persisted.tranquility));
+			queue_length: Some(self.manager.resync.queue_len().unwrap_or(0) as u64),
-
+			tranquility: Some(persisted.tranquility),
-		let qlen = self.manager.resync.queue_len().unwrap_or(0);
+			persistent_errors: Some(self.manager.resync.errors_len().unwrap_or(0) as u64),
-		if qlen > 0 {
+			..Default::default()
-			ret.push(format!("{} blocks in queue", qlen));
 		}
-
-		let elen = self.manager.resync.errors_len().unwrap_or(0);
-		if elen > 0 {
-			ret.push(format!("{} blocks in error state", elen));
-		}
-
-		Some(ret.join(", "))
 	}
 
 	async fn work(&mut self, _must_exit: &mut watch::Receiver<bool>) -> Result<WorkerState, Error> {
@@ -545,9 +558,9 @@ impl Worker for ResyncWorker {
 /// and the time of the last try.
 /// Used to implement exponential backoff.
 #[derive(Clone, Copy, Debug)]
-struct ErrorCounter {
+pub(crate) struct ErrorCounter {
-	errors: u64,
+	pub(crate) errors: u64,
-	last_try: u64,
+	pub(crate) last_try: u64,
 }
 
 impl ErrorCounter {
@@ -558,12 +571,13 @@ impl ErrorCounter {
 		}
 	}
 
-	fn decode(data: &[u8]) -> Self {
+	pub(crate) fn decode(data: &[u8]) -> Self {
 		Self {
 			errors: u64::from_be_bytes(data[0..8].try_into().unwrap()),
 			last_try: u64::from_be_bytes(data[8..16].try_into().unwrap()),
 		}
 	}
+
 	fn encode(&self) -> Vec<u8> {
 		[
 			u64::to_be_bytes(self.errors),
@@ -583,7 +597,8 @@ impl ErrorCounter {
 		(RESYNC_RETRY_DELAY.as_millis() as u64)
 			<< std::cmp::min(self.errors - 1, RESYNC_RETRY_DELAY_MAX_BACKOFF_POWER)
 	}
-	fn next_try(&self) -> u64 {
+
+	pub(crate) fn next_try(&self) -> u64 {
 		self.last_try + self.delay_msec()
 	}
 }

src/db/lib.rs

@@ -181,6 +181,10 @@ impl Tree {
 	pub fn len(&self) -> Result<usize> {
 		self.0.len(self.1)
 	}
+	#[inline]
+	pub fn fast_len(&self) -> Result<Option<usize>> {
+		self.0.fast_len(self.1)
+	}
 
 	#[inline]
 	pub fn first(&self) -> Result<Option<(Value, Value)>> {
@@ -323,6 +327,9 @@ pub(crate) trait IDb: Send + Sync {
 
 	fn get(&self, tree: usize, key: &[u8]) -> Result<Option<Value>>;
 	fn len(&self, tree: usize) -> Result<usize>;
+	fn fast_len(&self, _tree: usize) -> Result<Option<usize>> {
+		Ok(None)
+	}
 
 	fn insert(&self, tree: usize, key: &[u8], value: &[u8]) -> Result<Option<Value>>;
 	fn remove(&self, tree: usize, key: &[u8]) -> Result<Option<Value>>;

src/db/lmdb_adapter.rs

@@ -121,6 +121,10 @@ impl IDb for LmdbDb {
 		Ok(tree.len(&tx)?.try_into().unwrap())
 	}
 
+	fn fast_len(&self, tree: usize) -> Result<Option<usize>> {
+		Ok(Some(self.len(tree)?))
+	}
+
 	fn insert(&self, tree: usize, key: &[u8], value: &[u8]) -> Result<Option<Value>> {
 		let tree = self.get_tree(tree)?;
 		let mut tx = self.db.write_txn()?;

src/db/sqlite_adapter.rs

@@ -144,6 +144,10 @@ impl IDb for SqliteDb {
 		}
 	}
 
+	fn fast_len(&self, tree: usize) -> Result<Option<usize>> {
+		Ok(Some(self.len(tree)?))
+	}
+
 	fn insert(&self, tree: usize, key: &[u8], value: &[u8]) -> Result<Option<Value>> {
 		trace!("insert {}: lock db", tree);
 		let this = self.0.lock().unwrap();

src/garage/admin.rs

@@ -8,6 +8,7 @@ use serde::{Deserialize, Serialize};
 use garage_util::crdt::*;
 use garage_util::data::*;
 use garage_util::error::Error as GarageError;
+use garage_util::formater::format_table_to_string;
 use garage_util::time::*;
 
 use garage_table::replication::*;
@@ -15,6 +16,7 @@ use garage_table::*;
 
 use garage_rpc::*;
 
+use garage_block::manager::BlockResyncErrorInfo;
 use garage_block::repair::ScrubWorkerCommand;
 
 use garage_model::bucket_alias_table::*;
@@ -24,6 +26,8 @@ use garage_model::helper::error::{Error, OkOrBadRequest};
 use garage_model::key_table::*;
 use garage_model::migrate::Migrate;
 use garage_model::permission::*;
+use garage_model::s3::object_table::*;
+use garage_model::s3::version_table::Version;
 
 use crate::cli::*;
 use crate::repair::online::launch_online_repair;
@@ -38,7 +42,8 @@ pub enum AdminRpc {
 	LaunchRepair(RepairOpt),
 	Migrate(MigrateOpt),
 	Stats(StatsOpt),
-	Worker(WorkerOpt),
+	Worker(WorkerOperation),
+	BlockOperation(BlockOperation),
 
 	// Replies
 	Ok(String),
@@ -54,6 +59,13 @@ pub enum AdminRpc {
 		HashMap<usize, garage_util::background::WorkerInfo>,
 		WorkerListOpt,
 	),
+	WorkerInfo(usize, garage_util::background::WorkerInfo),
+	BlockErrorList(Vec<BlockResyncErrorInfo>),
+	BlockInfo {
+		hash: Hash,
+		refcount: u64,
+		versions: Vec<Result<Version, Uuid>>,
+	},
 }
 
 impl Rpc for AdminRpc {
@@ -73,6 +85,8 @@ impl AdminRpcHandler {
 		admin
 	}
 
+	// ================ BUCKET COMMANDS ====================
+
 	async fn handle_bucket_cmd(&self, cmd: &BucketOperation) -> Result<AdminRpc, Error> {
 		match cmd {
 			BucketOperation::List => self.handle_list_buckets().await,
@@ -551,6 +565,8 @@ impl AdminRpcHandler {
 		Ok(AdminRpc::Ok(ret))
 	}
 
+	// ================ KEY COMMANDS ====================
+
 	async fn handle_key_cmd(&self, cmd: &KeyOperation) -> Result<AdminRpc, Error> {
 		match cmd {
 			KeyOperation::List => self.handle_list_keys().await,
@@ -688,6 +704,8 @@ impl AdminRpcHandler {
 		Ok(AdminRpc::KeyInfo(key, relevant_buckets))
 	}
 
+	// ================ MIGRATION COMMANDS ====================
+
 	async fn handle_migrate(self: &Arc<Self>, opt: MigrateOpt) -> Result<AdminRpc, Error> {
 		if !opt.yes {
 			return Err(Error::BadRequest(
@@ -704,6 +722,8 @@ impl AdminRpcHandler {
 		Ok(AdminRpc::Ok("Migration successfull.".into()))
 	}
 
+	// ================ REPAIR COMMANDS ====================
+
 	async fn handle_launch_repair(self: &Arc<Self>, opt: RepairOpt) -> Result<AdminRpc, Error> {
 		if !opt.yes {
 			return Err(Error::BadRequest(
@@ -747,6 +767,8 @@ impl AdminRpcHandler {
 		}
 	}
 
+	// ================ STATS COMMANDS ====================
+
 	async fn handle_stats(&self, opt: StatsOpt) -> Result<AdminRpc, Error> {
 		if opt.all_nodes {
 			let mut ret = String::new();
@@ -763,11 +785,12 @@ impl AdminRpcHandler {
 				match self
 					.endpoint
 					.call(&node_id, AdminRpc::Stats(opt), PRIO_NORMAL)
-					.await?
+					.await
 				{
-					Ok(AdminRpc::Ok(s)) => writeln!(&mut ret, "{}", s).unwrap(),
+					Ok(Ok(AdminRpc::Ok(s))) => writeln!(&mut ret, "{}", s).unwrap(),
-					Ok(x) => writeln!(&mut ret, "Bad answer: {:?}", x).unwrap(),
+					Ok(Ok(x)) => writeln!(&mut ret, "Bad answer: {:?}", x).unwrap(),
-					Err(e) => writeln!(&mut ret, "Error: {}", e).unwrap(),
+					Ok(Err(e)) => writeln!(&mut ret, "Remote error: {}", e).unwrap(),
+					Err(e) => writeln!(&mut ret, "Network error: {}", e).unwrap(),
 				}
 			}
 			Ok(AdminRpc::Ok(ret))
@@ -787,6 +810,7 @@ impl AdminRpcHandler {
 				.unwrap_or_else(|| "(unknown)".into()),
 		)
 		.unwrap();
+
 		writeln!(&mut ret, "\nDatabase engine: {}", self.garage.db.engine()).unwrap();
 
 		// Gather ring statistics
@@ -805,21 +829,38 @@ impl AdminRpcHandler {
 			writeln!(&mut ret, "  {:?} {}", n, c).unwrap();
 		}
 
-		self.gather_table_stats(&mut ret, &self.garage.bucket_table, &opt)?;
+		// Gather table statistics
-		self.gather_table_stats(&mut ret, &self.garage.key_table, &opt)?;
+		let mut table = vec!["  Table\tItems\tMklItems\tMklTodo\tGcTodo".into()];
-		self.gather_table_stats(&mut ret, &self.garage.object_table, &opt)?;
+		table.push(self.gather_table_stats(&self.garage.bucket_table, opt.detailed)?);
-		self.gather_table_stats(&mut ret, &self.garage.version_table, &opt)?;
+		table.push(self.gather_table_stats(&self.garage.key_table, opt.detailed)?);
-		self.gather_table_stats(&mut ret, &self.garage.block_ref_table, &opt)?;
+		table.push(self.gather_table_stats(&self.garage.object_table, opt.detailed)?);
+		table.push(self.gather_table_stats(&self.garage.version_table, opt.detailed)?);
+		table.push(self.gather_table_stats(&self.garage.block_ref_table, opt.detailed)?);
+		write!(
+			&mut ret,
+			"\nTable stats:\n{}",
+			format_table_to_string(table)
+		)
+		.unwrap();
 
+		// Gather block manager statistics
 		writeln!(&mut ret, "\nBlock manager stats:").unwrap();
-		if opt.detailed {
+		let rc_len = if opt.detailed {
+			self.garage.block_manager.rc_len()?.to_string()
+		} else {
+			self.garage
+				.block_manager
+				.rc_fast_len()?
+				.map(|x| x.to_string())
+				.unwrap_or_else(|| "NC".into())
+		};
+
 		writeln!(
 			&mut ret,
 			"  number of RC entries (~= number of blocks): {}",
-				self.garage.block_manager.rc_len()?
+			rc_len
 		)
 		.unwrap();
-		}
 		writeln!(
 			&mut ret,
 			"  resync queue length: {}",
@@ -833,67 +874,84 @@ impl AdminRpcHandler {
 		)
 		.unwrap();
 
+		if !opt.detailed {
+			writeln!(&mut ret, "\nIf values are missing (marked as NC), consider adding the --detailed flag - this will be slow.").unwrap();
+		}
+
 		Ok(ret)
 	}
 
 	fn gather_table_stats<F, R>(
 		&self,
-		to: &mut String,
 		t: &Arc<Table<F, R>>,
-		opt: &StatsOpt,
+		detailed: bool,
-	) -> Result<(), Error>
+	) -> Result<String, Error>
 	where
 		F: TableSchema + 'static,
 		R: TableReplication + 'static,
 	{
-		writeln!(to, "\nTable stats for {}", F::TABLE_NAME).unwrap();
+		let (data_len, mkl_len) = if detailed {
-		if opt.detailed {
+			(
-			writeln!(
+				t.data.store.len().map_err(GarageError::from)?.to_string(),
-				to,
+				t.merkle_updater.merkle_tree_len()?.to_string(),
-				"  number of items: {}",
-				t.data.store.len().map_err(GarageError::from)?
 			)
-			.unwrap();
+		} else {
-			writeln!(
+			(
-				to,
+				t.data
-				"  Merkle tree size: {}",
+					.store
-				t.merkle_updater.merkle_tree_len()?
+					.fast_len()
+					.map_err(GarageError::from)?
+					.map(|x| x.to_string())
+					.unwrap_or_else(|| "NC".into()),
+				t.merkle_updater
+					.merkle_tree_fast_len()?
+					.map(|x| x.to_string())
+					.unwrap_or_else(|| "NC".into()),
 			)
-			.unwrap();
+		};
-		}
-		writeln!(
-			to,
-			"  Merkle updater todo queue length: {}",
-			t.merkle_updater.todo_len()?
-		)
-		.unwrap();
-		writeln!(to, "  GC todo queue length: {}", t.data.gc_todo_len()?).unwrap();
 
-		Ok(())
+		Ok(format!(
+			"  {}\t{}\t{}\t{}\t{}",
+			F::TABLE_NAME,
+			data_len,
+			mkl_len,
+			t.merkle_updater.todo_len()?,
+			t.data.gc_todo_len()?
+		))
 	}
 
-	// ----
+	// ================ WORKER COMMANDS ====================
 
-	async fn handle_worker_cmd(&self, opt: WorkerOpt) -> Result<AdminRpc, Error> {
+	async fn handle_worker_cmd(&self, cmd: &WorkerOperation) -> Result<AdminRpc, Error> {
-		match opt.cmd {
+		match cmd {
-			WorkerCmd::List { opt } => {
+			WorkerOperation::List { opt } => {
 				let workers = self.garage.background.get_worker_info();
-				Ok(AdminRpc::WorkerList(workers, opt))
+				Ok(AdminRpc::WorkerList(workers, *opt))
 			}
-			WorkerCmd::Set { opt } => match opt {
+			WorkerOperation::Info { tid } => {
+				let info = self
+					.garage
+					.background
+					.get_worker_info()
+					.get(tid)
+					.ok_or_bad_request(format!("No worker with TID {}", tid))?
+					.clone();
+				Ok(AdminRpc::WorkerInfo(*tid, info))
+			}
+			WorkerOperation::Set { opt } => match opt {
 				WorkerSetCmd::ScrubTranquility { tranquility } => {
-					let scrub_command = ScrubWorkerCommand::SetTranquility(tranquility);
+					let scrub_command = ScrubWorkerCommand::SetTranquility(*tranquility);
 					self.garage
 						.block_manager
 						.send_scrub_command(scrub_command)
 						.await;
 					Ok(AdminRpc::Ok("Scrub tranquility updated".into()))
 				}
-				WorkerSetCmd::ResyncNWorkers { n_workers } => {
+				WorkerSetCmd::ResyncWorkerCount { worker_count } => {
 					self.garage
 						.block_manager
 						.resync
-						.set_n_workers(n_workers)
+						.set_n_workers(*worker_count)
 						.await?;
 					Ok(AdminRpc::Ok("Number of resync workers updated".into()))
 				}
@@ -901,13 +959,154 @@ impl AdminRpcHandler {
 					self.garage
 						.block_manager
 						.resync
-						.set_tranquility(tranquility)
+						.set_tranquility(*tranquility)
 						.await?;
 					Ok(AdminRpc::Ok("Resync tranquility updated".into()))
 				}
 			},
 		}
 	}
+
+	// ================ BLOCK COMMANDS ====================
+
+	async fn handle_block_cmd(&self, cmd: &BlockOperation) -> Result<AdminRpc, Error> {
+		match cmd {
+			BlockOperation::ListErrors => Ok(AdminRpc::BlockErrorList(
+				self.garage.block_manager.list_resync_errors()?,
+			)),
+			BlockOperation::Info { hash } => {
+				let hash = hex::decode(hash).ok_or_bad_request("invalid hash")?;
+				let hash = Hash::try_from(&hash).ok_or_bad_request("invalid hash")?;
+				let refcount = self.garage.block_manager.get_block_rc(&hash)?;
+				let block_refs = self
+					.garage
+					.block_ref_table
+					.get_range(&hash, None, None, 10000, Default::default())
+					.await?;
+				let mut versions = vec![];
+				for br in block_refs {
+					if let Some(v) = self
+						.garage
+						.version_table
+						.get(&br.version, &EmptyKey)
+						.await?
+					{
+						versions.push(Ok(v));
+					} else {
+						versions.push(Err(br.version));
+					}
+				}
+				Ok(AdminRpc::BlockInfo {
+					hash,
+					refcount,
+					versions,
+				})
+			}
+			BlockOperation::RetryNow { all, blocks } => {
+				if *all {
+					if !blocks.is_empty() {
+						return Err(Error::BadRequest(
+							"--all was specified, cannot also specify blocks".into(),
+						));
+					}
+					let blocks = self.garage.block_manager.list_resync_errors()?;
+					for b in blocks.iter() {
+						self.garage.block_manager.resync.clear_backoff(&b.hash)?;
+					}
+					Ok(AdminRpc::Ok(format!(
+						"{} blocks returned in queue for a retry now (check logs to see results)",
+						blocks.len()
+					)))
+				} else {
+					for hash in blocks {
+						let hash = hex::decode(hash).ok_or_bad_request("invalid hash")?;
+						let hash = Hash::try_from(&hash).ok_or_bad_request("invalid hash")?;
+						self.garage.block_manager.resync.clear_backoff(&hash)?;
+					}
+					Ok(AdminRpc::Ok(format!(
+						"{} blocks returned in queue for a retry now (check logs to see results)",
+						blocks.len()
+					)))
+				}
+			}
+			BlockOperation::Purge { yes, blocks } => {
+				if !yes {
+					return Err(Error::BadRequest(
+						"Pass the --yes flag to confirm block purge operation.".into(),
+					));
+				}
+
+				let mut obj_dels = 0;
+				let mut ver_dels = 0;
+
+				for hash in blocks {
+					let hash = hex::decode(hash).ok_or_bad_request("invalid hash")?;
+					let hash = Hash::try_from(&hash).ok_or_bad_request("invalid hash")?;
+					let block_refs = self
+						.garage
+						.block_ref_table
+						.get_range(&hash, None, None, 10000, Default::default())
+						.await?;
+
+					for br in block_refs {
+						let version = match self
+							.garage
+							.version_table
+							.get(&br.version, &EmptyKey)
+							.await?
+						{
+							Some(v) => v,
+							None => continue,
+						};
+
+						if let Some(object) = self
+							.garage
+							.object_table
+							.get(&version.bucket_id, &version.key)
+							.await?
+						{
+							let ov = object.versions().iter().rev().find(|v| v.is_complete());
+							if let Some(ov) = ov {
+								if ov.uuid == br.version {
+									let del_uuid = gen_uuid();
+									let deleted_object = Object::new(
+										version.bucket_id,
+										version.key.clone(),
+										vec![ObjectVersion {
+											uuid: del_uuid,
+											timestamp: ov.timestamp + 1,
+											state: ObjectVersionState::Complete(
+												ObjectVersionData::DeleteMarker,
+											),
+										}],
+									);
+									self.garage.object_table.insert(&deleted_object).await?;
+									obj_dels += 1;
+								}
+							}
+						}
+
+						if !version.deleted.get() {
+							let deleted_version = Version::new(
+								version.uuid,
+								version.bucket_id,
+								version.key.clone(),
+								true,
+							);
+							self.garage.version_table.insert(&deleted_version).await?;
+							ver_dels += 1;
+						}
+					}
+				}
+				Ok(AdminRpc::Ok(format!(
+					"{} blocks were purged: {} object deletion markers added, {} versions marked deleted",
+					blocks.len(),
+					obj_dels,
+					ver_dels
+				)))
+			}
+		}
+	}
 }
 
 #[async_trait]
@@ -923,7 +1122,8 @@ impl EndpointHandler<AdminRpc> for AdminRpcHandler {
 			AdminRpc::Migrate(opt) => self.handle_migrate(opt.clone()).await,
 			AdminRpc::LaunchRepair(opt) => self.handle_launch_repair(opt.clone()).await,
 			AdminRpc::Stats(opt) => self.handle_stats(opt.clone()).await,
-			AdminRpc::Worker(opt) => self.handle_worker_cmd(opt.clone()).await,
+			AdminRpc::Worker(wo) => self.handle_worker_cmd(wo).await,
+			AdminRpc::BlockOperation(bo) => self.handle_block_cmd(bo).await,
 			m => Err(GarageError::unexpected_rpc_message(m).into()),
 		}
 	}

src/garage/cli/cmd.rs

@@ -41,6 +41,9 @@ pub async fn cli_command_dispatch(
 		}
 		Command::Stats(so) => cmd_admin(admin_rpc_endpoint, rpc_host, AdminRpc::Stats(so)).await,
 		Command::Worker(wo) => cmd_admin(admin_rpc_endpoint, rpc_host, AdminRpc::Worker(wo)).await,
+		Command::Block(bo) => {
+			cmd_admin(admin_rpc_endpoint, rpc_host, AdminRpc::BlockOperation(bo)).await
+		}
 		_ => unreachable!(),
 	}
 }
@@ -186,7 +189,20 @@ pub async fn cmd_admin(
 			print_key_info(&key, &rb);
 		}
 		AdminRpc::WorkerList(wi, wlo) => {
-			print_worker_info(wi, wlo);
+			print_worker_list(wi, wlo);
+		}
+		AdminRpc::WorkerInfo(tid, wi) => {
+			print_worker_info(tid, wi);
+		}
+		AdminRpc::BlockErrorList(el) => {
+			print_block_error_list(el);
+		}
+		AdminRpc::BlockInfo {
+			hash,
+			refcount,
+			versions,
+		} => {
+			print_block_info(hash, refcount, versions);
 		}
 		r => {
 			error!("Unexpected response: {:?}", r);

src/garage/cli/structs.rs

@@ -49,7 +49,11 @@ pub enum Command {
 
 	/// Manage background workers
 	#[structopt(name = "worker", version = garage_version())]
-	Worker(WorkerOpt),
+	Worker(WorkerOperation),
+
+	/// Low-level debug operations on data blocks
+	#[structopt(name = "block", version = garage_version())]
+	Block(BlockOperation),
 }
 
 #[derive(StructOpt, Debug)]
@@ -502,20 +506,17 @@ pub struct StatsOpt {
 	pub detailed: bool,
 }
 
-#[derive(Serialize, Deserialize, StructOpt, Debug, Clone)]
-pub struct WorkerOpt {
-	#[structopt(subcommand)]
-	pub cmd: WorkerCmd,
-}
-
 #[derive(Serialize, Deserialize, StructOpt, Debug, Eq, PartialEq, Clone)]
-pub enum WorkerCmd {
+pub enum WorkerOperation {
 	/// List all workers on Garage node
 	#[structopt(name = "list", version = garage_version())]
 	List {
 		#[structopt(flatten)]
 		opt: WorkerListOpt,
 	},
+	/// Get detailed information about a worker
+	#[structopt(name = "info", version = garage_version())]
+	Info { tid: usize },
 	/// Set worker parameter
 	#[structopt(name = "set", version = garage_version())]
 	Set {
@@ -540,9 +541,41 @@ pub enum WorkerSetCmd {
 	#[structopt(name = "scrub-tranquility", version = garage_version())]
 	ScrubTranquility { tranquility: u32 },
 	/// Set number of concurrent block resync workers
-	#[structopt(name = "resync-n-workers", version = garage_version())]
+	#[structopt(name = "resync-worker-count", version = garage_version())]
-	ResyncNWorkers { n_workers: usize },
+	ResyncWorkerCount { worker_count: usize },
 	/// Set tranquility of block resync operations
 	#[structopt(name = "resync-tranquility", version = garage_version())]
 	ResyncTranquility { tranquility: u32 },
 }
+
+#[derive(Serialize, Deserialize, StructOpt, Debug, Eq, PartialEq, Clone)]
+pub enum BlockOperation {
+	/// List all blocks that currently have a resync error
+	#[structopt(name = "list-errors", version = garage_version())]
+	ListErrors,
+	/// Get detailed information about a single block
+	#[structopt(name = "info", version = garage_version())]
+	Info {
+		/// Hash of the block for which to retrieve information
+		hash: String,
+	},
+	/// Retry now the resync of one or many blocks
+	#[structopt(name = "retry-now", version = garage_version())]
+	RetryNow {
+		/// Retry all blocks that have a resync error
+		#[structopt(long = "all")]
+		all: bool,
+		/// Hashes of the block to retry to resync now
+		blocks: Vec<String>,
+	},
+	/// Delete all objects referencing a missing block
+	#[structopt(name = "purge", version = garage_version())]
+	Purge {
+		/// Mandatory to confirm this operation
+		#[structopt(long = "yes")]
+		yes: bool,
+		/// Hashes of the block to purge
+		#[structopt(required = true)]
+		blocks: Vec<String>,
+	},
+}

src/garage/cli/util.rs

@@ -3,14 +3,17 @@ use std::time::Duration;
 
 use garage_util::background::*;
 use garage_util::crdt::*;
-use garage_util::data::Uuid;
+use garage_util::data::*;
 use garage_util::error::*;
 use garage_util::formater::format_table;
 use garage_util::time::*;
 
+use garage_block::manager::BlockResyncErrorInfo;
+
 use garage_model::bucket_table::*;
 use garage_model::key_table::*;
 use garage_model::s3::object_table::{BYTES, OBJECTS, UNFINISHED_UPLOADS};
+use garage_model::s3::version_table::Version;
 
 use crate::cli::structs::WorkerListOpt;
 
@@ -241,7 +244,7 @@ pub fn find_matching_node(
 	}
 }
 
-pub fn print_worker_info(wi: HashMap<usize, WorkerInfo>, wlo: WorkerListOpt) {
+pub fn print_worker_list(wi: HashMap<usize, WorkerInfo>, wlo: WorkerListOpt) {
 	let mut wi = wi.into_iter().collect::<Vec<_>>();
 	wi.sort_by_key(|(tid, info)| {
 		(
@@ -254,7 +257,7 @@ pub fn print_worker_info(wi: HashMap<usize, WorkerInfo>, wlo: WorkerListOpt) {
 		)
 	});
 
-	let mut table = vec![];
+	let mut table = vec!["TID\tState\tName\tTranq\tDone\tQueue\tErrors\tConsec\tLast".to_string()];
 	for (tid, info) in wi.iter() {
 		if wlo.busy && !matches!(info.state, WorkerState::Busy | WorkerState::Throttled(_)) {
 			continue;
@@ -263,33 +266,147 @@ pub fn print_worker_info(wi: HashMap<usize, WorkerInfo>, wlo: WorkerListOpt) {
 			continue;
 		}
 
-		table.push(format!("{}\t{}\t{}", tid, info.state, info.name));
-		if let Some(i) = &info.info {
-			table.push(format!("\t\t  {}", i));
-		}
 		let tf = timeago::Formatter::new();
-		let (err_ago, err_msg) = info
+		let err_ago = info
 			.last_error
 			.as_ref()
-			.map(|(m, t)| {
+			.map(|(_, t)| tf.convert(Duration::from_millis(now_msec() - t)))
-				(
+			.unwrap_or_default();
-					tf.convert(Duration::from_millis(now_msec() - t)),
+		let (total_err, consec_err) = if info.errors > 0 {
-					m.as_str(),
+			(info.errors.to_string(), info.consecutive_errors.to_string())
-				)
+		} else {
-			})
+			("-".into(), "-".into())
-			.unwrap_or(("(?) ago".into(), "(?)"));
+		};
-		if info.consecutive_errors > 0 {
+
 		table.push(format!(
-				"\t\t  {} consecutive errors ({} total), last {}",
+			"{}\t{}\t{}\t{}\t{}\t{}\t{}\t{}\t{}",
-				info.consecutive_errors, info.errors, err_ago,
+			tid,
+			info.state,
+			info.name,
+			info.status
+				.tranquility
+				.as_ref()
+				.map(ToString::to_string)
+				.unwrap_or_else(|| "-".into()),
+			info.status.progress.as_deref().unwrap_or("-"),
+			info.status
+				.queue_length
+				.as_ref()
+				.map(ToString::to_string)
+				.unwrap_or_else(|| "-".into()),
+			total_err,
+			consec_err,
+			err_ago,
 		));
-			table.push(format!("\t\t  {}", err_msg));
-		} else if info.errors > 0 {
-			table.push(format!("\t\t  ({} errors, last {})", info.errors, err_ago,));
-			if wlo.errors {
-				table.push(format!("\t\t  {}", err_msg));
 	}
+	format_table(table);
+}
+
+pub fn print_worker_info(tid: usize, info: WorkerInfo) {
+	let mut table = vec![];
+	table.push(format!("Task id:\t{}", tid));
+	table.push(format!("Worker name:\t{}", info.name));
+	match info.state {
+		WorkerState::Throttled(t) => {
+			table.push(format!(
+				"Worker state:\tBusy (throttled, paused for {:.3}s)",
+				t
+			));
+		}
+		s => {
+			table.push(format!("Worker state:\t{}", s));
+		}
+	};
+	if let Some(tql) = info.status.tranquility {
+		table.push(format!("Tranquility:\t{}", tql));
+	}
+
+	table.push("".into());
+	table.push(format!("Total errors:\t{}", info.errors));
+	table.push(format!("Consecutive errs:\t{}", info.consecutive_errors));
+	if let Some((s, t)) = info.last_error {
+		table.push(format!("Last error:\t{}", s));
+		let tf = timeago::Formatter::new();
+		table.push(format!(
+			"Last error time:\t{}",
+			tf.convert(Duration::from_millis(now_msec() - t))
+		));
+	}
+
+	table.push("".into());
+	if let Some(p) = info.status.progress {
+		table.push(format!("Progress:\t{}", p));
+	}
+	if let Some(ql) = info.status.queue_length {
+		table.push(format!("Queue length:\t{}", ql));
+	}
+	if let Some(pe) = info.status.persistent_errors {
+		table.push(format!("Persistent errors:\t{}", pe));
+	}
+
+	for (i, s) in info.status.freeform.iter().enumerate() {
+		if i == 0 {
+			if table.last() != Some(&"".into()) {
+				table.push("".into());
+			}
+			table.push(format!("Message:\t{}", s));
+		} else {
+			table.push(format!("\t{}", s));
 		}
 	}
 	format_table(table);
 }
+
+pub fn print_block_error_list(el: Vec<BlockResyncErrorInfo>) {
+	let now = now_msec();
+	let tf = timeago::Formatter::new();
+	let mut tf2 = timeago::Formatter::new();
+	tf2.ago("");
+
+	let mut table = vec!["Hash\tRC\tErrors\tLast error\tNext try".into()];
+	for e in el {
+		table.push(format!(
+			"{}\t{}\t{}\t{}\tin {}",
+			hex::encode(e.hash.as_slice()),
+			e.refcount,
+			e.error_count,
+			tf.convert(Duration::from_millis(now - e.last_try)),
+			tf2.convert(Duration::from_millis(e.next_try - now))
+		));
+	}
+	format_table(table);
+}
+
+pub fn print_block_info(hash: Hash, refcount: u64, versions: Vec<Result<Version, Uuid>>) {
+	println!("Block hash: {}", hex::encode(hash.as_slice()));
+	println!("Refcount: {}", refcount);
+	println!();
+
+	let mut table = vec!["Version\tBucket\tKey\tDeleted".into()];
+	let mut nondeleted_count = 0;
+	for v in versions.iter() {
+		match v {
+			Ok(ver) => {
+				table.push(format!(
+					"{:?}\t{:?}\t{}\t{:?}",
+					ver.uuid,
+					ver.bucket_id,
+					ver.key,
+					ver.deleted.get()
+				));
+				if !ver.deleted.get() {
+					nondeleted_count += 1;
+				}
+			}
+			Err(vh) => {
+				table.push(format!("{:?}\t\t\tyes", vh));
+			}
+		}
+	}
+	format_table(table);
+
+	if refcount != nondeleted_count {
+		println!();
+		println!("Warning: refcount does not match number of non-deleted versions");
+	}
+}

src/garage/main.rs

@@ -127,9 +127,16 @@ async fn main() {
 		std::process::abort();
 	}));
 
+	// Parse arguments and dispatch command line
+	let opt = Opt::from_clap(&Opt::clap().version(version.as_str()).get_matches());
+
 	// Initialize logging as well as other libraries used in Garage
 	if std::env::var("RUST_LOG").is_err() {
-		std::env::set_var("RUST_LOG", "netapp=info,garage=info")
+		let default_log = match &opt.cmd {
+			Command::Server => "netapp=info,garage=info",
+			_ => "netapp=warn,garage=warn",
+		};
+		std::env::set_var("RUST_LOG", default_log)
 	}
 	tracing_subscriber::fmt()
 		.with_writer(std::io::stderr)
@@ -137,9 +144,6 @@ async fn main() {
 		.init();
 	sodiumoxide::init().expect("Unable to init sodiumoxide");
 
-	// Parse arguments and dispatch command line
-	let opt = Opt::from_clap(&Opt::clap().version(version.as_str()).get_matches());
-
 	let res = match opt.cmd {
 		Command::Server => server::run_server(opt.config_file).await,
 		Command::OfflineRepair(repair_opt) => {
@@ -182,9 +186,9 @@ async fn cli_command(opt: Opt) -> Result<(), Error> {
 	let netapp = NetApp::new(GARAGE_VERSION_TAG, network_key, sk);
 
 	// Find and parse the address of the target host
-	let (id, addr) = if let Some(h) = opt.rpc_host {
+	let (id, addr, is_default_addr) = if let Some(h) = opt.rpc_host {
 		let (id, addrs) = parse_and_resolve_peer_addr(&h).ok_or_else(|| format!("Invalid RPC remote node identifier: {}. Expected format is <pubkey>@<IP or hostname>:<port>.", h))?;
-		(id, addrs[0])
+		(id, addrs[0], false)
 	} else {
 		let node_id = garage_rpc::system::read_node_id(&config.as_ref().unwrap().metadata_dir)
 			.err_context(READ_KEY_ERROR)?;
@@ -195,24 +199,26 @@ async fn cli_command(opt: Opt) -> Result<(), Error> {
 				.ok_or_message("unable to resolve rpc_public_addr specified in config file")?
 				.next()
 				.ok_or_message("unable to resolve rpc_public_addr specified in config file")?;
-			(node_id, a)
+			(node_id, a, false)
 		} else {
 			let default_addr = SocketAddr::new(
 				"127.0.0.1".parse().unwrap(),
 				config.as_ref().unwrap().rpc_bind_addr.port(),
 			);
-			warn!(
+			(node_id, default_addr, true)
-				"Trying to contact Garage node at default address {}",
-				default_addr
-			);
-			warn!("If this doesn't work, consider adding rpc_public_addr in your config file or specifying the -h command line parameter.");
-			(node_id, default_addr)
 		}
 	};
 
 	// Connect to target host
-	netapp.clone().try_connect(addr, id).await
+	if let Err(e) = netapp.clone().try_connect(addr, id).await {
-		.err_context("Unable to connect to destination RPC host. Check that you are using the same value of rpc_secret as them, and that you have their correct public key.")?;
+		if is_default_addr {
+			warn!(
+				"Tried to contact Garage node at default address {}, which didn't work. If that address is wrong, consider setting rpc_public_addr in your config file.",
+				addr
+			);
+		}
+		Err(e).err_context("Unable to connect to destination RPC host. Check that you are using the same value of rpc_secret as them, and that you have their correct public key.")?;
+	}
 
 	let system_rpc_endpoint = netapp.endpoint::<SystemRpc, ()>(SYSTEM_RPC_PATH.into());
 	let admin_rpc_endpoint = netapp.endpoint::<AdminRpc, ()>(ADMIN_RPC_PATH.into());

src/garage/repair/online.rs

@@ -85,8 +85,11 @@ impl Worker for RepairVersionsWorker {
 		"Version repair worker".into()
 	}
 
-	fn info(&self) -> Option<String> {
+	fn status(&self) -> WorkerStatus {
-		Some(format!("{} items done", self.counter))
+		WorkerStatus {
+			progress: Some(self.counter.to_string()),
+			..Default::default()
+		}
 	}
 
 	async fn work(&mut self, _must_exit: &mut watch::Receiver<bool>) -> Result<WorkerState, Error> {
@@ -163,8 +166,11 @@ impl Worker for RepairBlockrefsWorker {
 		"Block refs repair worker".into()
 	}
 
-	fn info(&self) -> Option<String> {
+	fn status(&self) -> WorkerStatus {
-		Some(format!("{} items done", self.counter))
+		WorkerStatus {
+			progress: Some(self.counter.to_string()),
+			..Default::default()
+		}
 	}
 
 	async fn work(&mut self, _must_exit: &mut watch::Receiver<bool>) -> Result<WorkerState, Error> {

src/model/index_counter.rs

@@ -404,14 +404,13 @@ impl<T: CountedItem> IndexPropagatorWorker<T> {
 #[async_trait]
 impl<T: CountedItem> Worker for IndexPropagatorWorker<T> {
 	fn name(&self) -> String {
-		format!("{} index counter propagator", T::COUNTER_TABLE_NAME)
+		format!("{} counter", T::COUNTER_TABLE_NAME)
 	}
 
-	fn info(&self) -> Option<String> {
+	fn status(&self) -> WorkerStatus {
-		if !self.buf.is_empty() {
+		WorkerStatus {
-			Some(format!("{} items in queue", self.buf.len()))
+			queue_length: Some(self.buf.len() as u64),
-		} else {
+			..Default::default()
-			None
 		}
 	}
 

src/table/data.rs

@@ -58,7 +58,13 @@ where
 			.expect("Unable to open DB tree");
 		let gc_todo = CountedTree::new(gc_todo).expect("Cannot count gc_todo_v2");
 
-		let metrics = TableMetrics::new(F::TABLE_NAME, merkle_todo.clone(), gc_todo.clone());
+		let metrics = TableMetrics::new(
+			F::TABLE_NAME,
+			store.clone(),
+			merkle_tree.clone(),
+			merkle_todo.clone(),
+			gc_todo.clone(),
+		);
 
 		Arc::new(Self {
 			system,

src/table/gc.rs

@@ -330,12 +330,10 @@ where
 		format!("{} GC", F::TABLE_NAME)
 	}
 
-	fn info(&self) -> Option<String> {
+	fn status(&self) -> WorkerStatus {
-		let l = self.gc.data.gc_todo_len().unwrap_or(0);
+		WorkerStatus {
-		if l > 0 {
+			queue_length: Some(self.gc.data.gc_todo_len().unwrap_or(0) as u64),
-			Some(format!("{} items in queue", l))
+			..Default::default()
-		} else {
-			None
 		}
 	}
 

src/table/merkle.rs

@@ -293,6 +293,10 @@ where
 		Ok(self.data.merkle_tree.len()?)
 	}
 
+	pub fn merkle_tree_fast_len(&self) -> Result<Option<usize>, Error> {
+		Ok(self.data.merkle_tree.fast_len()?)
+	}
+
 	pub fn todo_len(&self) -> Result<usize, Error> {
 		Ok(self.data.merkle_todo.len()?)
 	}
@@ -310,15 +314,13 @@ where
 	R: TableReplication + 'static,
 {
 	fn name(&self) -> String {
-		format!("{} Merkle tree updater", F::TABLE_NAME)
+		format!("{} Merkle", F::TABLE_NAME)
 	}
 
-	fn info(&self) -> Option<String> {
+	fn status(&self) -> WorkerStatus {
-		let l = self.0.todo_len().unwrap_or(0);
+		WorkerStatus {
-		if l > 0 {
+			queue_length: Some(self.0.todo_len().unwrap_or(0) as u64),
-			Some(format!("{} items in queue", l))
+			..Default::default()
-		} else {
-			None
 		}
 	}
 

src/table/metrics.rs

@@ -5,6 +5,8 @@ use garage_db::counted_tree_hack::CountedTree;
 
 /// TableMetrics reference all counter used for metrics
 pub struct TableMetrics {
+	pub(crate) _table_size: ValueObserver<u64>,
+	pub(crate) _merkle_tree_size: ValueObserver<u64>,
 	pub(crate) _merkle_todo_len: ValueObserver<u64>,
 	pub(crate) _gc_todo_len: ValueObserver<u64>,
 
@@ -20,9 +22,43 @@ pub struct TableMetrics {
 	pub(crate) sync_items_received: Counter<u64>,
 }
 impl TableMetrics {
-	pub fn new(table_name: &'static str, merkle_todo: db::Tree, gc_todo: CountedTree) -> Self {
+	pub fn new(
+		table_name: &'static str,
+		store: db::Tree,
+		merkle_tree: db::Tree,
+		merkle_todo: db::Tree,
+		gc_todo: CountedTree,
+	) -> Self {
 		let meter = global::meter(table_name);
 		TableMetrics {
+			_table_size: meter
+				.u64_value_observer(
+					"table.size",
+					move |observer| {
+						if let Ok(Some(v)) = store.fast_len() {
+							observer.observe(
+								v as u64,
+								&[KeyValue::new("table_name", table_name)],
+							);
+						}
+					},
+				)
+				.with_description("Number of items in table")
+				.init(),
+			_merkle_tree_size: meter
+				.u64_value_observer(
+					"table.merkle_tree_size",
+					move |observer| {
+						if let Ok(Some(v)) = merkle_tree.fast_len() {
+							observer.observe(
+								v as u64,
+								&[KeyValue::new("table_name", table_name)],
+							);
+						}
+					},
+				)
+				.with_description("Number of nodes in table's Merkle tree")
+				.init(),
 			_merkle_todo_len: meter
 				.u64_value_observer(
 					"table.merkle_updater_todo_queue_length",

src/table/sync.rs

@@ -570,12 +570,10 @@ impl<F: TableSchema + 'static, R: TableReplication + 'static> Worker for SyncWor
 		format!("{} sync", F::TABLE_NAME)
 	}
 
-	fn info(&self) -> Option<String> {
+	fn status(&self) -> WorkerStatus {
-		let l = self.todo.len();
+		WorkerStatus {
-		if l > 0 {
+			queue_length: Some(self.todo.len() as u64),
-			Some(format!("{} partitions remaining", l))
+			..Default::default()
-		} else {
-			None
 		}
 	}
 

src/table/util.rs

@@ -49,3 +49,9 @@ impl EnumerationOrder {
 		}
 	}
 }
+
+impl Default for EnumerationOrder {
+	fn default() -> Self {
+		EnumerationOrder::Forward
+	}
+}

src/util/background/mod.rs

@@ -29,13 +29,24 @@ pub struct BackgroundRunner {
 #[derive(Clone, Serialize, Deserialize, Debug)]
 pub struct WorkerInfo {
 	pub name: String,
-	pub info: Option<String>,
+	pub status: WorkerStatus,
 	pub state: WorkerState,
 	pub errors: usize,
 	pub consecutive_errors: usize,
 	pub last_error: Option<(String, u64)>,
 }
 
+/// WorkerStatus is a struct returned by the worker with a bunch of canonical
+/// fields to indicate their status to CLI users. All fields are optional.
+#[derive(Clone, Serialize, Deserialize, Debug, Default)]
+pub struct WorkerStatus {
+	pub tranquility: Option<u32>,
+	pub progress: Option<String>,
+	pub queue_length: Option<u64>,
+	pub persistent_errors: Option<u64>,
+	pub freeform: Vec<String>,
+}
+
 impl BackgroundRunner {
 	/// Create a new BackgroundRunner
 	pub fn new(

src/util/background/worker.rs

@@ -10,7 +10,7 @@ use serde::{Deserialize, Serialize};
 use tokio::select;
 use tokio::sync::{mpsc, watch};
 
-use crate::background::WorkerInfo;
+use crate::background::{WorkerInfo, WorkerStatus};
 use crate::error::Error;
 use crate::time::now_msec;
 
@@ -26,7 +26,7 @@ impl std::fmt::Display for WorkerState {
 	fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
 		match self {
 			WorkerState::Busy => write!(f, "Busy"),
-			WorkerState::Throttled(t) => write!(f, "Thr:{:.3}", t),
+			WorkerState::Throttled(_) => write!(f, "Busy*"),
 			WorkerState::Idle => write!(f, "Idle"),
 			WorkerState::Done => write!(f, "Done"),
 		}
@@ -37,8 +37,8 @@ impl std::fmt::Display for WorkerState {
 pub trait Worker: Send {
 	fn name(&self) -> String;
 
-	fn info(&self) -> Option<String> {
+	fn status(&self) -> WorkerStatus {
-		None
+		Default::default()
 	}
 
 	/// Work: do a basic unit of work, if one is available (otherwise, should return
@@ -119,7 +119,7 @@ impl WorkerProcessor {
 						match wi.get_mut(&worker.task_id) {
 							Some(i) => {
 								i.state = worker.state;
-								i.info = worker.worker.info();
+								i.status = worker.worker.status();
 								i.errors = worker.errors;
 								i.consecutive_errors = worker.consecutive_errors;
 								if worker.last_error.is_some() {
@@ -130,7 +130,7 @@ impl WorkerProcessor {
 								wi.insert(worker.task_id, WorkerInfo {
 									name: worker.worker.name(),
 									state: worker.state,
-									info: worker.worker.info(),
+									status: worker.worker.status(),
 									errors: worker.errors,
 									consecutive_errors: worker.consecutive_errors,
 									last_error: worker.last_error.take(),

src/util/formater.rs

@@ -1,4 +1,4 @@
-pub fn format_table(data: Vec<String>) {
+pub fn format_table_to_string(data: Vec<String>) -> String {
 	let data = data
 		.iter()
 		.map(|s| s.split('\t').collect::<Vec<_>>())
@@ -24,5 +24,9 @@ pub fn format_table(data: Vec<String>) {
 		out.push('\n');
 	}
 
-	print!("{}", out);
+	out
+}
+
+pub fn format_table(data: Vec<String>) {
+	print!("{}", format_table_to_string(data));
 }