pruner: stop advancing tail on delete failure

execution_chain/pruner.nim

@@ -90,7 +90,11 @@ proc pruneLoop(pruner: BackgroundPrunerRef) {.async: (raises: [CancelledError]).
       if header.timestamp >= cutoff:
         break
 
-      kvt.deleteBlockBodyAndReceiptsBe(header)
+      if not kvt.deleteBlockBodyAndReceiptsBe(header):
+        warn "Background pruner: failed to delete block data",
+          blkNum = currentBlock
+        break
+
       currentBlock += 1
       blocksSinceSave += 1
 

execution_chain/pruner/db_utils.nim

@@ -25,43 +25,60 @@ logScope:
 # Direct-backend deletion helpers (bypass transaction layer)
 # ------------------------------------------------------------------------------
 
-proc deleteTransactionsBe(kvt: KvtDbRef, txRoot: Hash32) =
+proc deleteTransactionsBe(kvt: KvtDbRef, txRoot: Hash32): bool =
   if txRoot == EMPTY_ROOT_HASH:
-    return
+    return true
 
   kvt.delRangeBe(
     hashIndexKey(txRoot, 0), hashIndexKey(txRoot, uint16.high), compactRange = true
   ).isOkOr:
     warn "pruner: deleteTransactionsBe", txRoot, error
+    return false
 
-proc deleteReceiptsBe(kvt: KvtDbRef, receiptsRoot: Hash32) =
+  true
+
+proc deleteReceiptsBe(kvt: KvtDbRef, receiptsRoot: Hash32): bool =
   if receiptsRoot == EMPTY_ROOT_HASH:
-    return
+    return true
 
   kvt.delRangeBe(
     hashIndexKey(receiptsRoot, 0),
     hashIndexKey(receiptsRoot, uint16.high),
     compactRange = true,
   ).isOkOr:
     warn "pruner: deleteReceiptsBe", receiptsRoot, error
+    return false
+
+  true
 
-proc deleteUnclesBe(kvt: KvtDbRef, ommersHash: Hash32) =
+proc deleteUnclesBe(kvt: KvtDbRef, ommersHash: Hash32): bool =
   if ommersHash == EMPTY_UNCLE_HASH:
-    return
+    return true
+
   kvt.delBe(genericHashKey(ommersHash).toOpenArray).isOkOr:
     warn "pruner: deleteUnclesBe", ommersHash, error
+    return false
 
-proc deleteWithdrawalsBe(kvt: KvtDbRef, withdrawalsRoot: Hash32) =
+  true
+
+proc deleteWithdrawalsBe(kvt: KvtDbRef, withdrawalsRoot: Hash32): bool =
   if withdrawalsRoot == EMPTY_ROOT_HASH:
-    return
+    return true
+
   kvt.delBe(withdrawalsKey(withdrawalsRoot).toOpenArray).isOkOr:
     warn "pruner: deleteWithdrawalsBe", withdrawalsRoot, error
+    return false
+
+  true
 
-proc deleteBlockBodyAndReceiptsBe*(kvt: KvtDbRef, header: Header) =
-  kvt.deleteTransactionsBe(header.transactionsRoot)
-  kvt.deleteUnclesBe(header.ommersHash)
+proc deleteBlockBodyAndReceiptsBe*(kvt: KvtDbRef, header: Header): bool =
+  if not kvt.deleteTransactionsBe(header.transactionsRoot):
+    return false
+  if not kvt.deleteUnclesBe(header.ommersHash):
+    return false
   if header.withdrawalsRoot.isSome:
-    kvt.deleteWithdrawalsBe(header.withdrawalsRoot.get())
+    if not kvt.deleteWithdrawalsBe(header.withdrawalsRoot.get()):
+      return false
   kvt.deleteReceiptsBe(header.receiptsRoot)
 
 # ------------------------------------------------------------------------------

tests/test_pruner.nim

@@ -271,6 +271,51 @@ suite "Pruner integration tests":
     for blkNum in 1'u64 .. 3'u64:
       check bt2.getBlockHeader(BlockNumber blkNum).isOk
 
+  test "pruner does not advance tail when backend deletion fails":
+    let com = env.newCom()
+    var chain = ForkedChainRef.init(com, baseDistance = 0, persistBatchSize = 1)
+    let
+      genesis = Block.init(com.genesisHeader, BlockBody())
+      baseTxFrame = com.db.baseTxFrame()
+      txFrame = baseTxFrame.txFrameBegin
+      blk1 = txFrame.makeBlk(1, genesis)
+      blk2 = txFrame.makeBlk(2, blk1)
+      blk3 = txFrame.makeBlk(3, blk2)
+    txFrame.dispose()
+
+    check (waitFor chain.importBlock(blk1)).isOk
+    check (waitFor chain.forkChoice(blk1.blockHash, blk1.blockHash)).isOk
+    check (waitFor chain.importBlock(blk2)).isOk
+    check (waitFor chain.forkChoice(blk2.blockHash, blk2.blockHash)).isOk
+    check (waitFor chain.importBlock(blk3)).isOk
+    check (waitFor chain.forkChoice(blk3.blockHash, blk3.blockHash)).isOk
+
+    let
+      kvt = com.db.kvt
+      hdr1 = com.db.baseTxFrame().getBlockHeader(BlockNumber 1).expect("header exists")
+      wdRoot1 = hdr1.withdrawalsRoot.get()
+      originalDelKvpFn = kvt.delKvpFn
+
+    check kvt.hasBe(withdrawalsKey(wdRoot1).toOpenArray)
+    kvt.putBe(tailIdKey().toOpenArray, BlockNumber(1).toBytesLE())
+
+    kvt.delKvpFn =
+      proc(key: openArray[byte]): Result[void, KvtError] {.gcsafe, raises: [].} =
+        discard key
+        err(RdbBeDriverDelError)
+
+    let pruner = BackgroundPrunerRef.init(com,
+      batchSize = 10,
+      loopDelay = chronos.milliseconds(50))
+    pruner.start()
+
+    waitFor sleepAsync(chronos.milliseconds(150))
+    waitFor pruner.stop()
+    kvt.delKvpFn = originalDelKvpFn
+
+    check kvt.getHistoryExpiredBe() == BlockNumber(1)
+    check kvt.hasBe(withdrawalsKey(wdRoot1).toOpenArray)
+
   test "getHistoryExpiredBe returns 0 when not set":
     let com = env.newCom()
     let kvt = com.db.kvt