From ccb2291bcc3b80f3cdc0e0d1350e3008a1108c6c Mon Sep 17 00:00:00 2001 From: Alexandru Gheorghe Date: Thu, 12 Dec 2024 20:27:14 +0200 Subject: [PATCH 1/2] Fix canonicalize off by one Approval voting canonicalize is off by one that means if we are finalizing blocks one by one, approval-voting cleans it up every other block because for example: - With 1, 2, 3, 4, 5, 6 blocks created, the stored range would be StoredBlockRange(1,7) - When block 3 is finalized the canonicalize works and StoredBlockRange is (4,7) - When block 4 is finalized the canonicalize exists early because of the `if range.0 > canon_number` break clause, so blocks are not cleaned up. - When block 5 is finalized the canonicalize works and StoredBlockRange becomes (6,7). The consequences of this is that sometimes we keep block entries around after they are finalized, so at restart we consider this blocks and send them to approval-distribution. In this case if finality is lagging for example at block 5 after approval-distribution receives 4 as being the oldest block it needs to work on, and since BlockFinalized is never resent for block 4, that is the block on which it will decide to finalize things. Signed-off-by: Alexandru Gheorghe --- .../src/approval_db/v3/tests.rs | 52 +++++++++++++++++-- polkadot/node/core/approval-voting/src/ops.rs | 2 +- 2 files changed, 50 insertions(+), 4 deletions(-) diff --git a/polkadot/node/core/approval-voting/src/approval_db/v3/tests.rs b/polkadot/node/core/approval-voting/src/approval_db/v3/tests.rs index 372dd49803cb..69278868fa3d 100644 --- a/polkadot/node/core/approval-voting/src/approval_db/v3/tests.rs +++ b/polkadot/node/core/approval-voting/src/approval_db/v3/tests.rs @@ -264,8 +264,8 @@ fn add_block_entry_adds_child() { fn canonicalize_works() { let (mut db, store) = make_db(); - // -> B1 -> C1 -> D1 - // A -> B2 -> C2 -> D2 + // -> B1 -> C1 -> D1 -> E1 + // A -> B2 -> C2 -> D2 -> E2 // // We'll canonicalize C1. Everything except D1 should disappear. // @@ -293,18 +293,22 @@ fn canonicalize_works() { let block_hash_c2 = Hash::repeat_byte(5); let block_hash_d1 = Hash::repeat_byte(6); let block_hash_d2 = Hash::repeat_byte(7); + let block_hash_e1 = Hash::repeat_byte(8); + let block_hash_e2 = Hash::repeat_byte(9); let candidate_receipt_genesis = make_candidate(ParaId::from(1_u32), genesis); let candidate_receipt_a = make_candidate(ParaId::from(2_u32), block_hash_a); let candidate_receipt_b = make_candidate(ParaId::from(3_u32), block_hash_a); let candidate_receipt_b1 = make_candidate(ParaId::from(4_u32), block_hash_b1); let candidate_receipt_c1 = make_candidate(ParaId::from(5_u32), block_hash_c1); + let candidate_receipt_e1 = make_candidate(ParaId::from(6_u32), block_hash_e1); let cand_hash_1 = candidate_receipt_genesis.hash(); let cand_hash_2 = candidate_receipt_a.hash(); let cand_hash_3 = candidate_receipt_b.hash(); let cand_hash_4 = candidate_receipt_b1.hash(); let cand_hash_5 = candidate_receipt_c1.hash(); + let cand_hash_6 = candidate_receipt_e1.hash(); let block_entry_a = make_block_entry(block_hash_a, genesis, 1, Vec::new()); let block_entry_b1 = make_block_entry(block_hash_b1, block_hash_a, 2, Vec::new()); @@ -326,6 +330,12 @@ fn canonicalize_works() { let block_entry_d2 = make_block_entry(block_hash_d2, block_hash_c2, 4, vec![(CoreIndex(0), cand_hash_5)]); + let block_entry_e1 = + make_block_entry(block_hash_e1, block_hash_d1, 5, vec![(CoreIndex(0), cand_hash_6)]); + + let block_entry_e2 = + make_block_entry(block_hash_e2, block_hash_d2, 5, vec![(CoreIndex(0), cand_hash_6)]); + let candidate_info = { let mut candidate_info = HashMap::new(); candidate_info.insert( @@ -345,6 +355,8 @@ fn canonicalize_works() { candidate_info .insert(cand_hash_5, NewCandidateInfo::new(candidate_receipt_c1, GroupIndex(5), None)); + candidate_info + .insert(cand_hash_6, NewCandidateInfo::new(candidate_receipt_e1, GroupIndex(6), None)); candidate_info }; @@ -357,6 +369,8 @@ fn canonicalize_works() { block_entry_c2.clone(), block_entry_d1.clone(), block_entry_d2.clone(), + block_entry_e1.clone(), + block_entry_e2.clone(), ]; let mut overlay_db = OverlayedBackend::new(&db); @@ -438,7 +452,7 @@ fn canonicalize_works() { assert_eq!( load_stored_blocks(store.as_ref(), &TEST_CONFIG).unwrap().unwrap(), - StoredBlockRange(4, 5) + StoredBlockRange(4, 6) ); check_candidates_in_store(vec![ @@ -447,6 +461,7 @@ fn canonicalize_works() { (cand_hash_3, Some(vec![block_hash_d1])), (cand_hash_4, Some(vec![block_hash_d1])), (cand_hash_5, None), + (cand_hash_6, Some(vec![block_hash_e1])), ]); check_blocks_in_store(vec![ @@ -456,6 +471,37 @@ fn canonicalize_works() { (block_hash_c1, None), (block_hash_c2, None), (block_hash_d1, Some(vec![cand_hash_3, cand_hash_4])), + (block_hash_e1, Some(vec![cand_hash_6])), + (block_hash_d2, None), + ]); + + let mut overlay_db = OverlayedBackend::new(&db); + canonicalize(&mut overlay_db, 4, block_hash_d1).unwrap(); + let write_ops = overlay_db.into_write_ops(); + db.write(write_ops).unwrap(); + + assert_eq!( + load_stored_blocks(store.as_ref(), &TEST_CONFIG).unwrap().unwrap(), + StoredBlockRange(5, 6) + ); + + check_candidates_in_store(vec![ + (cand_hash_1, None), + (cand_hash_2, None), + (cand_hash_3, None), + (cand_hash_4, None), + (cand_hash_5, None), + (cand_hash_6, Some(vec![block_hash_e1])), + ]); + + check_blocks_in_store(vec![ + (block_hash_a, None), + (block_hash_b1, None), + (block_hash_b2, None), + (block_hash_c1, None), + (block_hash_c2, None), + (block_hash_d1, None), + (block_hash_e1, Some(vec![cand_hash_6])), (block_hash_d2, None), ]); } diff --git a/polkadot/node/core/approval-voting/src/ops.rs b/polkadot/node/core/approval-voting/src/ops.rs index f105580009fa..efdc8780da62 100644 --- a/polkadot/node/core/approval-voting/src/ops.rs +++ b/polkadot/node/core/approval-voting/src/ops.rs @@ -90,7 +90,7 @@ pub fn canonicalize( ) -> SubsystemResult<()> { let range = match overlay_db.load_stored_blocks()? { None => return Ok(()), - Some(range) if range.0 >= canon_number => return Ok(()), + Some(range) if range.0 > canon_number => return Ok(()), Some(range) => range, }; From 3b25bdd1dee907351bdbe585e366ef8c040b7034 Mon Sep 17 00:00:00 2001 From: Alexandru Gheorghe <49718502+alexggh@users.noreply.github.com> Date: Fri, 13 Dec 2024 11:33:38 +0200 Subject: [PATCH 2/2] Create pr_6864.prdoc --- prdoc/pr_6864.prdoc | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) create mode 100644 prdoc/pr_6864.prdoc diff --git a/prdoc/pr_6864.prdoc b/prdoc/pr_6864.prdoc new file mode 100644 index 000000000000..6d6c84e22da4 --- /dev/null +++ b/prdoc/pr_6864.prdoc @@ -0,0 +1,18 @@ +# Schema: Polkadot SDK PRDoc Schema (prdoc) v1.0.0 +# See doc at https://raw.githubusercontent.com/paritytech/polkadot-sdk/master/prdoc/schema_user.json + +title: Fix approval-voting canonicalize off by one + +doc: + - audience: Node Dev + description: | + The approval-voting canonicalize was off by one, which lead to blocks being + cleaned up every other 2 blocks. Normally, this is not an issue, but on restart + we might end up sending NewBlocks to approval-distribution with finalized blocks. + This would be problematic in the case were finalization was already lagging before + restart, so after restart approval-distribution will trigger aggression on the wrong + already finalized block. + +crates: + - name: polkadot-node-core-approval-voting + bump: minor