TN11 parameter fine-tuning (#356)

* simpa defaults loglevel to trace in this module anyhow

* minor optimization: iterate locator hashes from earlier to later

* revalidate orphan blocks pool following IBD

* slightly increase orphan resolution range (for 10bps it means increasing to 9 -> meaning block locator reaches blue depth of 2^9=512)

* limit max block parents to 16 also on high bps

* make sure virtual gives a chance to all mergable tips and not only to the  max_block_parents * 3 candidates with highest blue work

* decrease the `qualified as synced` period for high bps testnet

* new tn11 genesis

* review comments ++

* tighter bound for max orphans

* remove unclear temp comment

consensus/core/src/blockstatus.rs

@@ -43,4 +43,8 @@ impl BlockStatus {
     pub fn is_valid(self) -> bool {
         self != BlockStatus::StatusInvalid
     }
+
+    pub fn is_invalid(self) -> bool {
+        self == BlockStatus::StatusInvalid
+    }
 }

consensus/core/src/config/bps.rs

@@ -58,6 +58,18 @@ impl<const BPS: u64> Bps<BPS> {
         let val = (Self::ghostdag_k() / 2) as u8;
         if val < 10 {
             10
+        // TODO (TEMP): uncomment when restarting TN11 or when implementing a TN11 HF
+        /*
+        } else if val > 16 {
+            // We currently limit the number of parents by 16 in order to preserve processing performance
+            // and to prevent number of parent references per network round from growing quadratically with
+            // BPS. As BPS might grow beyond 10 this will mean that blocks will reference less parents than
+            // the average number of DAG tips. Which means relying on randomness between network peers for ensuring
+            // that all tips are eventually merged. We conjecture that with high probability every block will
+            // be merged after a log number of rounds. For mainnet this requires an increase to the value of GHOSTDAG
+            // K accompanied by a short security analysis, or moving to the parameterless DAGKNIGHT.
+            16
+         */
         } else {
             val
         }
@@ -67,6 +79,16 @@ impl<const BPS: u64> Bps<BPS> {
         Self::ghostdag_k() as u64 * 10
     }
 
+    // TODO (TEMP): rename to mergeset_size_limit when restarting TN11 or when implementing a TN11 HF
+    pub const fn _mergeset_size_limit() -> u64 {
+        let val = Self::ghostdag_k() as u64 * 2;
+        if val < 180 {
+            180
+        } else {
+            val
+        }
+    }
+
     pub const fn merge_depth_bound() -> u64 {
         BPS * MERGE_DEPTH_DURATION
     }
@@ -87,7 +109,7 @@ impl<const BPS: u64> Bps<BPS> {
     }
 
     pub const fn pruning_proof_m() -> u64 {
-        // No need to scale this constant with BPS since the important block levels (higher) remain logarithmically long
+        // No need to scale this constant with BPS since the important block levels (higher) remain logarithmically short
         PRUNING_PROOF_M
     }
 

consensus/core/src/config/constants.rs

@@ -59,7 +59,7 @@ pub mod consensus {
     /// Minimal size of the difficulty window. Affects the DA algorithm only at the starting period of a new net
     pub const MIN_DIFFICULTY_WINDOW_LEN: usize = 10;
 
-    /// **Legacy** difficulty adjustment window size corresponding to ~46 minutes with 1 BPS
+    /// **Legacy** difficulty adjustment window size corresponding to ~44 minutes with 1 BPS
     pub const LEGACY_DIFFICULTY_WINDOW_SIZE: usize = 2641;
 
     /// **New** difficulty window duration expressed in time units (seconds).

consensus/core/src/config/genesis.rs

@@ -143,10 +143,24 @@ pub const TESTNET_GENESIS: GenesisBlock = GenesisBlock {
 
 pub const TESTNET11_GENESIS: GenesisBlock = GenesisBlock {
     hash: Hash::from_bytes([
-        0x5a, 0x90, 0xf8, 0x71, 0x09, 0x32, 0x3d, 0x61, 0x41, 0xff, 0x51, 0x04, 0xa2, 0xd5, 0xf8, 0xd8, 0x85, 0x7a, 0x6f, 0x39, 0x2e,
-        0xb4, 0x90, 0x5c, 0xe3, 0x55, 0x5e, 0xc9, 0x12, 0xcd, 0xfb, 0x9c,
+        0x3c, 0x8d, 0x1b, 0xea, 0xd4, 0x65, 0xd4, 0xf7, 0x93, 0xf4, 0xb5, 0x20, 0x1a, 0x99, 0x22, 0x43, 0x75, 0xe2, 0x3b, 0x33, 0xd4,
+        0x54, 0x9f, 0x36, 0x07, 0xc2, 0xa9, 0xf9, 0x51, 0xe4, 0xec, 0xc4,
+    ]),
+    hash_merkle_root: Hash::from_bytes([
+        0xf5, 0xd7, 0x3a, 0xef, 0xd9, 0x1d, 0x82, 0x1a, 0xde, 0x39, 0xc8, 0x9a, 0x73, 0x2d, 0xc2, 0x1b, 0xa0, 0xab, 0x82, 0x42, 0xe0,
+        0x48, 0xdc, 0x2f, 0x26, 0x88, 0x1d, 0x6e, 0x7c, 0x00, 0x4e, 0xe0,
     ]),
     bits: 504155340, // see `gen_testnet11_genesis`
+    #[rustfmt::skip]
+    coinbase_payload: &[
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // Blue score
+        0x00, 0xE1, 0xF5, 0x05, 0x00, 0x00, 0x00, 0x00, // Subsidy
+        0x00, 0x00, // Script version
+        0x01,                                                                         // Varint
+        0x00,                                                                         // OP-FALSE
+        0x6b, 0x61, 0x73, 0x70, 0x61, 0x2d, 0x74, 0x65, 0x73, 0x74, 0x6e, 0x65, 0x74, // kaspa-testnet
+        11, 3                                                                         // TN11, Relaunch 3
+    ],
     ..TESTNET_GENESIS
 };
 
@@ -217,7 +231,7 @@ mod tests {
     fn test_genesis_hashes() {
         [GENESIS, TESTNET_GENESIS, TESTNET11_GENESIS, SIMNET_GENESIS, DEVNET_GENESIS].into_iter().for_each(|genesis| {
             let block: Block = (&genesis).into();
-            assert_eq!(calc_hash_merkle_root(block.transactions.iter()), block.header.hash_merkle_root);
+            assert_hashes_eq(calc_hash_merkle_root(block.transactions.iter()), block.header.hash_merkle_root);
             assert_hashes_eq(block.hash(), genesis.hash);
         });
     }

consensus/core/src/config/params.rs

@@ -216,10 +216,22 @@ impl Params {
 
     /// Returns whether the sink timestamp is recent enough and the node is considered synced or nearly synced.
     pub fn is_nearly_synced(&self, sink_timestamp: u64, sink_daa_score: u64) -> bool {
-        // We consider the node close to being synced if the sink (virtual selected parent) block
-        // timestamp is within DAA window duration far in the past. Blocks mined over such DAG state would
-        // enter the DAA window of fully-synced nodes and thus contribute to overall network difficulty
-        unix_now() < sink_timestamp + self.expected_daa_window_duration_in_milliseconds(sink_daa_score)
+        if self.net.is_mainnet() {
+            // We consider the node close to being synced if the sink (virtual selected parent) block
+            // timestamp is within DAA window duration far in the past. Blocks mined over such DAG state would
+            // enter the DAA window of fully-synced nodes and thus contribute to overall network difficulty
+            unix_now() < sink_timestamp + self.expected_daa_window_duration_in_milliseconds(sink_daa_score)
+        } else {
+            // For testnets we consider the node to be synced if the sink timestamp is within a time range which
+            // is overwhelmingly unlikely to pass without mined blocks even if net hashrate decreased dramatically.
+            //
+            // This period is smaller than the above mainnet calculation in order to ensure that an IBDing miner
+            // with significant testnet hashrate does not overwhelm the network with deep side-DAGs.
+            //
+            // We use DAA duration as baseline and scale it down with BPS
+            let max_expected_duration_without_blocks_in_milliseconds = self.target_time_per_block * NEW_DIFFICULTY_WINDOW_DURATION; // = DAA duration in milliseconds / bps
+            unix_now() < sink_timestamp + max_expected_duration_without_blocks_in_milliseconds
+        }
     }
 
     pub fn network_name(&self) -> String {

consensus/src/pipeline/virtual_processor/processor.rs

@@ -80,7 +80,7 @@ use crossbeam_channel::{Receiver as CrossbeamReceiver, Sender as CrossbeamSender
 use itertools::Itertools;
 use kaspa_utils::binary_heap::BinaryHeapExtensions;
 use parking_lot::{RwLock, RwLockUpgradableReadGuard};
-use rand::seq::SliceRandom;
+use rand::{seq::SliceRandom, Rng};
 use rayon::{
     prelude::{IntoParallelRefIterator, IntoParallelRefMutIterator, ParallelIterator},
     ThreadPool,
@@ -176,8 +176,10 @@ impl VirtualStateProcessor {
             thread_pool,
 
             genesis: params.genesis.clone(),
-            max_block_parents: params.max_block_parents,
-            mergeset_size_limit: params.mergeset_size_limit,
+            // TODO (TEMP): remove TN11 bounds when restarting/HF TN11, see comments in bps.rs
+            // (changing these values here is a way to influence the mined templates w/o breaking consensus)
+            max_block_parents: params.max_block_parents.min(16),
+            mergeset_size_limit: params.mergeset_size_limit.min(248),
             pruning_depth: params.pruning_depth,
 
             db,
@@ -522,7 +524,9 @@ impl VirtualStateProcessor {
         drop(selected_chain_write);
     }
 
-    /// Returns the max number of tips to consider as virtual parents in a single virtual resolve operation
+    /// Returns the max number of tips to consider as virtual parents in a single virtual resolve operation.
+    ///
+    /// Guaranteed to be `>= self.max_block_parents`
     fn max_virtual_parent_candidates(&self) -> usize {
         // Limit to max_block_parents x 3 candidates. This way we avoid going over thousands of tips when the network isn't healthy.
         // There's no specific reason for a factor of 3, and its not a consensus rule, just an estimation for reducing the amount
@@ -574,11 +578,7 @@ impl VirtualStateProcessor {
                     let filtering_blue_work = self.ghostdag_primary_store.get_blue_work(filtering_root).unwrap_or_default();
                     return (
                         candidate,
-                        heap.into_sorted_iter()
-                            .take(self.max_virtual_parent_candidates())
-                            .take_while(|s| s.blue_work >= filtering_blue_work)
-                            .map(|s| s.hash)
-                            .collect(),
+                        heap.into_sorted_iter().take_while(|s| s.blue_work >= filtering_blue_work).map(|s| s.hash).collect(),
                     );
                 } else {
                     debug!("Block candidate {} has invalid UTXO state and is ignored from Virtual chain.", candidate)
@@ -614,16 +614,32 @@ impl VirtualStateProcessor {
         // TODO: tests
 
         // Mergeset increasing might traverse DAG areas which are below the finality point and which theoretically
-        // can borderline with pruned data, hence we acquire the prune lock to insure data consistency. Note that
+        // can borderline with pruned data, hence we acquire the prune lock to ensure data consistency. Note that
         // the final selected mergeset can never be pruned (this is the essence of the prunality proof), however
         // we might touch such data prior to validating the bounded merge rule. All in all, this function is short
         // enough so we avoid making further optimizations
         let _prune_guard = self.pruning_lock.blocking_read();
         let max_block_parents = self.max_block_parents as usize;
+        let max_candidates = self.max_virtual_parent_candidates();
 
         // Prioritize half the blocks with highest blue work and pick the rest randomly to ensure diversity between nodes
-        if candidates.len() > max_block_parents / 2 {
-            // `make_contiguous` should be a no op since the deque was just built
+        if candidates.len() > max_candidates {
+            // make_contiguous should be a no op since the deque was just built
+            let slice = candidates.make_contiguous();
+
+            // Keep slice[..max_block_parents / 2] as is, choose max_candidates - max_block_parents / 2 in random
+            // from the remainder of the slice while swapping them to slice[max_block_parents / 2..max_candidates].
+            //
+            // Inspired by rand::partial_shuffle (which lacks the guarantee on chosen elements location).
+            for i in max_block_parents / 2..max_candidates {
+                let j = rand::thread_rng().gen_range(i..slice.len()); // i < max_candidates < slice.len()
+                slice.swap(i, j);
+            }
+
+            // Truncate the unchosen elements
+            candidates.truncate(max_candidates);
+        } else if candidates.len() > max_block_parents / 2 {
+            // Fallback to a simpler algo in this case
             candidates.make_contiguous()[max_block_parents / 2..].shuffle(&mut rand::thread_rng());
         }
 

protocol/flows/src/flow_context.rs

@@ -59,6 +59,9 @@ const PROTOCOL_VERSION: u32 = 6;
 /// See `check_orphan_resolution_range`
 const BASELINE_ORPHAN_RESOLUTION_RANGE: u32 = 5;
 
+/// Orphans are kept as full blocks so we cannot hold too much of them in memory
+const MAX_ORPHANS_UPPER_BOUND: usize = 1024;
+
 /// The min time to wait before allowing another parallel request
 const REQUEST_SCOPE_WAIT_TIME: Duration = Duration::from_secs(1);
 
@@ -203,11 +206,11 @@ impl FlowContext {
     ) -> Self {
         let hub = Hub::new();
 
-        let orphan_resolution_range = BASELINE_ORPHAN_RESOLUTION_RANGE + (config.bps() as f64).log2().min(3.0) as u32;
+        let orphan_resolution_range = BASELINE_ORPHAN_RESOLUTION_RANGE + (config.bps() as f64).log2().ceil() as u32;
 
-        // The maximum amount of orphans allowed in the orphans pool. This number is an
-        // approximation of how many orphans there can possibly be on average.
-        let max_orphans = 2u64.pow(orphan_resolution_range) as usize * config.ghostdag_k as usize;
+        // The maximum amount of orphans allowed in the orphans pool. This number is an approximation
+        // of how many orphans there can possibly be on average bounded by an upper bound.
+        let max_orphans = (2u64.pow(orphan_resolution_range) as usize * config.ghostdag_k as usize).min(MAX_ORPHANS_UPPER_BOUND);
         Self {
             inner: Arc::new(FlowContextInner {
                 node_id: Uuid::new_v4().into(),
@@ -360,6 +363,10 @@ impl FlowContext {
         unorphaned_blocks
     }
 
+    pub async fn revalidate_orphans(&self, consensus: &ConsensusProxy) {
+        self.orphans_pool.write().await.revalidate_orphans(consensus).await
+    }
+
     /// Adds the rpc-submitted block to the DAG and propagates it to peers.
     pub async fn submit_rpc_block(&self, consensus: &ConsensusProxy, block: Block) -> Result<(), ProtocolError> {
         if block.transactions.is_empty() {

protocol/flows/src/flowcontext/orphans.rs

@@ -136,6 +136,27 @@ impl OrphanBlocksPool {
             }
         })
     }
+
+    /// Iterate all orphans and remove blocks which are no longer orphans.
+    /// This is important for the overall health of the pool and for ensuring that
+    /// orphan blocks don't evict due to pool size limit while already processed
+    /// blocks remain in it. Should be called following IBD.  
+    pub async fn revalidate_orphans(&mut self, consensus: &ConsensusProxy) {
+        let mut i = 0;
+        while i < self.orphans.len() {
+            if let Some((&h, _)) = self.orphans.get_index(i) {
+                if consensus.async_get_block_status(h).await.is_some_and(|s| s.is_invalid() || s.has_block_body()) {
+                    // If we swap removed do not advance i so that we revisit the new element moved
+                    // to i in the next iteration. Loop will progress because len is shorter now.
+                    self.orphans.swap_remove_index(i);
+                } else {
+                    i += 1;
+                }
+            } else {
+                i += 1;
+            }
+        }
+    }
 }
 
 #[cfg(test)]
@@ -183,6 +204,8 @@ mod tests {
         let b = Block::from_precomputed_hash(9.into(), vec![]);
         let c = Block::from_precomputed_hash(10.into(), roots.clone());
         let d = Block::from_precomputed_hash(11.into(), vec![10.into()]);
+        let e = Block::from_precomputed_hash(12.into(), vec![10.into()]);
+        let f = Block::from_precomputed_hash(13.into(), vec![12.into()]);
 
         pool.add_orphan(c.clone());
         pool.add_orphan(d.clone());
@@ -192,11 +215,24 @@ mod tests {
         consensus.validate_and_insert_block(a.clone()).virtual_state_task.await.unwrap();
         consensus.validate_and_insert_block(b.clone()).virtual_state_task.await.unwrap();
 
+        // Test unorphaning
         let (blocks, _, virtual_state_tasks) = pool.unorphan_blocks(&consensus, 8.into()).await;
         try_join_all(virtual_state_tasks).await.unwrap();
         assert_eq!(blocks.into_iter().map(|b| b.hash()).collect::<HashSet<_>>(), HashSet::from([10.into(), 11.into()]));
         assert!(pool.orphans.is_empty());
 
-        drop((a, b, c, d));
+        // Test revalidation
+        pool.add_orphan(d.clone());
+        pool.add_orphan(e.clone());
+        pool.add_orphan(f.clone());
+        assert_eq!(pool.orphans.len(), 3);
+        pool.revalidate_orphans(&consensus).await;
+        assert_eq!(pool.orphans.len(), 2);
+        consensus.validate_and_insert_block(e.clone()).virtual_state_task.await.unwrap();
+        consensus.validate_and_insert_block(f.clone()).virtual_state_task.await.unwrap();
+        pool.revalidate_orphans(&consensus).await;
+        assert!(pool.orphans.is_empty());
+
+        drop((a, b, c, d, e, f));
     }
 }

protocol/flows/src/v5/blockrelay/flow.rs

@@ -251,7 +251,12 @@ impl HandleRelayInvsFlow {
             .await?;
         let msg = dequeue_with_timeout!(self.msg_route, Payload::BlockLocator)?;
         let locator_hashes: Vec<Hash> = msg.try_into()?;
-        for h in locator_hashes {
+        // Locator hashes are sent from later to earlier, so it makes sense to query consensus in reverse. Technically
+        // with current syncer-side implementations (in both go-kaspa and this codebase) we could query only the last one,
+        // but we prefer not relying on such details for correctness
+        //
+        // TODO: change syncer-side to only send the most early block since it's sufficient for our needs
+        for h in locator_hashes.into_iter().rev() {
             if consensus.async_get_block_status(h).await.is_some_and(|s| s.has_block_body()) {
                 return Ok(true);
             }

protocol/flows/src/v5/ibd/flow.rs

@@ -129,7 +129,12 @@ impl IbdFlow {
 
         // Relay block might be in the antipast of syncer sink, thus
         // check its past for missing bodies as well.
-        self.sync_missing_block_bodies(&session, relay_block.hash()).await
+        self.sync_missing_block_bodies(&session, relay_block.hash()).await?;
+
+        // Following IBD we revalidate orphans since many of them might have been processed during the IBD
+        self.ctx.revalidate_orphans(&session).await;
+
+        Ok(())
     }
 
     async fn determine_ibd_type(

simpa/src/main.rs

@@ -325,7 +325,7 @@ async fn validate(src_consensus: &Consensus, dst_consensus: &Consensus, params:
     for (i, mut chunk) in iter.enumerate() {
         let current_joins = submit_chunk(src_consensus, dst_consensus, &mut chunk);
         let statuses = try_join_all(prev_joins).await.unwrap();
-        info!("Validated chunk {}", i);
+        trace!("Validated chunk {}", i);
         assert!(statuses.iter().all(|s| s.is_utxo_valid_or_pending()));
         prev_joins = current_joins;
     }