diff --git a/hstream-kafka/HStream/Kafka/Server/Handler/Produce.hs b/hstream-kafka/HStream/Kafka/Server/Handler/Produce.hs
index ad19d2b57..23ef1045f 100644
--- a/hstream-kafka/HStream/Kafka/Server/Handler/Produce.hs
+++ b/hstream-kafka/HStream/Kafka/Server/Handler/Produce.hs
@@ -4,6 +4,7 @@ module HStream.Kafka.Server.Handler.Produce
   ) where
 
 import qualified Control.Concurrent.Async              as Async
+import           Control.Exception
 import           Control.Monad
 import           Data.ByteString                       (ByteString)
 import qualified Data.ByteString                       as BS
@@ -85,33 +86,6 @@ handleProduce ServerContext{..} _reqCtx req = do
                   , logStartOffset  = -1
                   }
         True -> do
-          -- FIXME: Block is too deep. Extract to a standalone function.
-          -- Wirte appends
-          (S.AppendCompletion{..}, offset) <-
-            appendRecords True scLDClient scOffsetManager
-                          (topic.name, partition.index) logid recordBytes
-
-          Log.debug1 $ "Append done " <> Log.build appendCompLogID
-                    <> ", lsn: " <> Log.build appendCompLSN
-                    <> ", start offset: " <> Log.build offset
-
-          -- TODO: performance improvements
-          --
-          -- For each append request after version 5, we need to read the oldest
-          -- offset of the log. This will cause critical performance problems.
-          --
-          --logStartOffset <-
-          --  if reqCtx.apiVersion >= 5
-          --     then do m_logStartOffset <- K.getOldestOffset scOffsetManager logid
-          --             case m_logStartOffset of
-          --               Just logStartOffset -> pure logStartOffset
-          --               Nothing -> do
-          --                 Log.fatal $ "Cannot get log start offset for logid "
-          --                          <> Log.build logid
-          --                 pure (-1)
-          --     else pure (-1)
-          let logStartOffset = (-1)
-
           -- TODO: PartitionProduceResponse.logAppendTimeMs
           --
           -- The timestamp returned by broker after appending the messages. If
@@ -120,13 +94,31 @@ handleProduce ServerContext{..} _reqCtx req = do
           -- local time when the messages are appended.
           --
           -- Currently, only support LogAppendTime
-          pure $ K.PartitionProduceResponse
-            { index           = partition.index
-            , errorCode       = K.NONE
-            , baseOffset      = offset
-            , logAppendTimeMs = appendCompTimestamp
-            , logStartOffset  = logStartOffset
-            }
+          catches (do
+            (S.AppendCompletion{..}, offset) <-
+              appendRecords True scLDClient scOffsetManager
+                                 (topic.name, partition.index) logid recordBytes
+            Log.debug1 $ "Append done " <> Log.build appendCompLogID
+                      <> ", lsn: " <> Log.build appendCompLSN
+                      <> ", start offset: " <> Log.build offset
+            pure $ K.PartitionProduceResponse
+              { index           = partition.index
+              , errorCode       = K.NONE
+              , baseOffset      = offset
+              , logAppendTimeMs = appendCompTimestamp
+              , logStartOffset  = (-1) -- TODO: getLogStartOffset
+              })
+            [ Handler (\(K.DecodeError (ec, msg))-> do
+                Log.debug1 $ "Append DecodeError " <> Log.buildString' ec
+                          <> ", " <> Log.buildString' msg
+                pure $ K.PartitionProduceResponse
+                  { index           = partition.index
+                  , errorCode       = ec
+                  , baseOffset      = (-1)
+                  , logAppendTimeMs = (-1)
+                  , logStartOffset  = (-1)
+                  })
+            ]
 
     pure $ K.TopicProduceResponse topic.name (K.KaArray $ Just partitionResponses)
 
@@ -158,7 +150,8 @@ appendRecords
   -> ByteString
   -> IO (S.AppendCompletion, Int64)
 appendRecords shouldValidateCrc ldclient om (streamName, partition) logid bs = do
-  (batchLength, offsetOffsets) <- K.decodeBatchRecordsForProduce shouldValidateCrc bs
+  batch <- K.decodeRecordBatch shouldValidateCrc bs
+  let batchLength = batch.recordsCount
   when (batchLength < 1) $ error "Invalid batch length"
 
   -- Offset wroten into storage is the max key in the batch, but return the min
@@ -185,7 +178,7 @@ appendRecords shouldValidateCrc ldclient om (streamName, partition) logid bs = d
         appendKey = U.intToCBytesWithPadding o
         appendAttrs = Just [(S.KeyTypeFindKey, appendKey)]
 
-    K.unsafeAlterBatchRecordsBsForProduce (+ startOffset) offsetOffsets bs
+    K.unsafeUpdateRecordBatchBaseOffset bs (+ startOffset)
 
     -- FIXME unlikely overflow: convert batchLength from Int to Int32
     let storedRecord = K.runPut $ K.RecordFormat 0{- version -}
@@ -204,3 +197,21 @@ appendRecords shouldValidateCrc ldclient om (streamName, partition) logid bs = d
     M.withLabel M.topicTotalAppendMessages partLabel $ \counter ->
       void $ M.addCounter counter (fromIntegral batchLength)
     pure (r, startOffset)
+
+-- TODO: performance improvements
+--
+-- For each append request after version 5, we need to read the oldest
+-- offset of the log. This will cause critical performance problems.
+--
+--logStartOffset <-
+--  if reqCtx.apiVersion >= 5
+--     then do m_logStartOffset <- K.getOldestOffset scOffsetManager logid
+--             case m_logStartOffset of
+--               Just logStartOffset -> pure logStartOffset
+--               Nothing -> do
+--                 Log.fatal $ "Cannot get log start offset for logid "
+--                          <> Log.build logid
+--                 pure (-1)
+--     else pure (-1)
+getLogStartOffset :: IO Int64
+getLogStartOffset = pure (-1)