[FLASH-296] [DM] Use Background Threads To Run Delta Merge Operations (…

…pingcap#266)

* Support merge delta in background.
* Avoid slow down query after delete range.
* Add a new sql feature manage table tb delete range 100, to test delete range.

dbms/src/Common/Allocator.cpp

@@ -126,7 +126,7 @@ void * Allocator<clear_memory_>::realloc(void * buf, size_t old_size, size_t new
         buf = ::realloc(buf, new_size);
 
         if (nullptr == buf)
-            DB::throwFromErrno("Allocator: Cannot realloc from " + formatReadableSizeWithBinarySuffix(old_size) + " to " + formatReadableSizeWithBinarySuffix(new_size) + ".", DB::ErrorCodes::CANNOT_ALLOCATE_MEMORY);
+            DB::throwFromErrno("Allocator: Cannot realloc from " + formatReadableSizeWithBinarySuffix(old_size) + DB::toString(old_size) + " to " + formatReadableSizeWithBinarySuffix(new_size) + DB::toString(new_size) + ".", DB::ErrorCodes::CANNOT_ALLOCATE_MEMORY);
 
         if (clear_memory && new_size > old_size)
             memset(reinterpret_cast<char *>(buf) + old_size, 0, new_size - old_size);

dbms/src/Interpreters/InterpreterManageQuery.cpp

@@ -46,6 +46,11 @@ BlockIO InterpreterManageQuery::execute()
             manageable_storage->checkStatus(context);
             return {};
         }
+        case ManageOperation::Enum ::DeleteRows:
+        {
+            manageable_storage->deleteRows(context, ast.rows);
+            return {};
+        }
     }
     return {};
 }

dbms/src/Interpreters/Settings.h

@@ -237,7 +237,7 @@ struct Settings
     M(SettingUInt64, mutable_deduper, 5, "The deduper used by MutableMergeTree storage. By default 5. 0: OriginStreams, 1: OriginUnity, 2: ReplacingUnity, 3: ReplacingPartitioning, 4: DedupPartitioning, 5: ReplacingPartitioningOpt.")\
     M(SettingUInt64, delta_merge_size, 10000000, "The delta rows limit in memory. After that delta rows will be flushed.")\
     \
-    M(SettingUInt64, dm_segment_rows, 1048576, "")\
+    M(SettingUInt64, dm_segment_limit_rows, 1048576, "")\
     M(SettingUInt64, dm_segment_delta_limit_rows, 104857, "")\
     M(SettingUInt64, dm_segment_delta_limit_bytes, 67108864, "")\
     M(SettingUInt64, dm_segment_delta_cache_limit_rows, 26214, "")\

dbms/src/Parsers/ASTManageQuery.h

@@ -12,12 +12,13 @@ namespace ManageOperation
         Flush,
         Status,
         Check,
+        DeleteRows,
     };
 
     inline const char * toString(UInt64 op)
     {
-        static const char * data[] = {"Flush", "Status", "Check"};
-        return op < 3 ? data[op] : "Unknown operation";
+        static const char * data[] = {"Flush", "Status", "Check", "Delete Rows"};
+        return op < 4 ? data[op] : "Unknown operation";
     }
 }
 
@@ -31,6 +32,8 @@ class ASTManageQuery : public IAST
 
     ManageOperation::Enum operation;
 
+    size_t rows = 0;
+
     /** Get the text that identifies this element. */
     String getID() const override
     {
@@ -51,6 +54,8 @@ class ASTManageQuery : public IAST
                       << (!database.empty() ? backQuoteIfNeed(database) + "." : "") << backQuoteIfNeed(table) << " "
                       << (settings.hilite ? hilite_keyword : "") << ManageOperation::toString(operation)
                       << (settings.hilite ? hilite_none : "");
+        if(operation == ManageOperation::Enum::DeleteRows)
+            settings.ostr << " " << rows;
     }
 };
 }

dbms/src/Parsers/ParserInsertQuery.cpp

@@ -38,6 +38,7 @@ bool ParserInsertQuery::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
     ParserKeyword s_values("VALUES");
     ParserKeyword s_format("FORMAT");
     ParserKeyword s_select("SELECT");
+    ParserKeyword s_selraw("SELRAW");
     ParserKeyword s_with("WITH");
     ParserToken s_lparen(TokenType::OpeningRoundBracket);
     ParserToken s_rparen(TokenType::ClosingRoundBracket);
@@ -137,7 +138,7 @@ bool ParserInsertQuery::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
         if (data < end && *data == '\n')
             ++data;
     }
-    else if (s_select.ignore(pos, expected) || s_with.ignore(pos,expected))
+    else if (s_select.ignore(pos, expected) || s_selraw.ignore(pos, expected) || s_with.ignore(pos,expected))
     {
         pos = before_select;
         ParserSelectWithUnionQuery select_p;

dbms/src/Parsers/ParserManageQuery.cpp

@@ -17,6 +17,7 @@ bool ParserManageQuery::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
     ParserKeyword s_flush("FLUSH");
     ParserKeyword s_status("STATUS");
     ParserKeyword s_check("CHECK");
+    ParserKeyword s_delete_rows("DELETE ROWS");
 
     ParserToken s_dot(TokenType::Dot);
     ParserIdentifier name_p;
@@ -37,25 +38,34 @@ bool ParserManageQuery::parseImpl(Pos & pos, ASTPtr & node, Expected & expected)
             return false;
     }
 
+    auto query = std::make_shared<ASTManageQuery>();
+    node = query;
+
+    if (database)
+        query->database = typeid_cast<const ASTIdentifier &>(*database).name;
+    if (table)
+        query->table = typeid_cast<const ASTIdentifier &>(*table).name;
+
     if (s_flush.ignore(pos, expected))
         operation = ManageOperation::Enum::Flush;
     else if (s_status.ignore(pos, expected))
         operation = ManageOperation::Enum::Status;
     else if (s_check.ignore(pos, expected))
         operation = ManageOperation::Enum::Check;
+    else if (s_delete_rows.ignore(pos, expected))
+    {
+        operation = ManageOperation::Enum::DeleteRows;
+        ParserNumber num;
+        ASTPtr rows;
+        if (!num.parse(pos, rows, expected))
+            return false;
+        query->rows = safeGet<UInt64>(typeid_cast<ASTLiteral &>(*rows).value);
+    }
     else
         return false;
 
-    auto query = std::make_shared<ASTManageQuery>();
-    node = query;
-
-    if (database)
-        query->database = typeid_cast<const ASTIdentifier &>(*database).name;
-    if (table)
-        query->table = typeid_cast<const ASTIdentifier &>(*table).name;
-
     query->operation = operation;
 
     return true;
 }
-}
+} // namespace DB

dbms/src/Storages/DeltaMerge/Chunk.cpp

@@ -116,7 +116,7 @@ Chunks createRefChunks(const Chunks & chunks, const GenPageId & gen_data_page_id
 }
 
 void serializeChunks(
-    WriteBuffer & buf, Chunks::const_iterator begin, Chunks ::const_iterator end, const Chunk * extra1, const Chunk * extra2)
+    WriteBuffer & buf, Chunks::const_iterator begin, Chunks::const_iterator end, const Chunk * extra1, const Chunk * extra2)
 {
     auto size = (UInt64)(end - begin);
     if (extra1)
@@ -133,6 +133,17 @@ void serializeChunks(
         extra2->serialize(buf);
 }
 
+void serializeChunks(WriteBuffer & buf, Chunks::const_iterator begin, Chunks ::const_iterator end, const Chunks & extra_chunks)
+{
+    auto size = (UInt64)(end - begin) + extra_chunks.size();
+    writeIntBinary(size, buf);
+
+    for (; begin != end; ++begin)
+        (*begin).serialize(buf);
+    for (auto & chunk : extra_chunks)
+        chunk.serialize(buf);
+}
+
 Chunks deserializeChunks(ReadBuffer & buf)
 {
     Chunks chunks;

dbms/src/Storages/DeltaMerge/Chunk.h

@@ -39,6 +39,7 @@ class Chunk
     // Binary version of chunk
     using Version = UInt32;
     static const Version CURRENT_VERSION;
+
 public:
     using ColumnMetaMap = std::unordered_map<ColId, ColumnMeta>;
 
@@ -122,11 +123,16 @@ using GenPageId = std::function<PageId()>;
 Chunk  createRefChunk(const Chunk & chunk, const GenPageId & gen_data_page_id, WriteBatch & wb);
 Chunks createRefChunks(const Chunks & chunks, const GenPageId & gen_data_page_id, WriteBatch & wb);
 
-void   serializeChunks(WriteBuffer &           buf,
-                       Chunks::const_iterator  begin,
-                       Chunks ::const_iterator end,
-                       const Chunk *           extra1 = nullptr,
-                       const Chunk *           extra2 = nullptr);
+void serializeChunks(WriteBuffer &           buf,
+                     Chunks::const_iterator  begin,
+                     Chunks::const_iterator end,
+                     const Chunk *           extra1 = nullptr,
+                     const Chunk *           extra2 = nullptr);
+void serializeChunks(WriteBuffer &           buf, //
+                     Chunks::const_iterator  begin,
+                     Chunks::const_iterator end,
+                     const Chunks &          extr_chunks);
+
 Chunks deserializeChunks(ReadBuffer & buf);
 
 Chunk prepareChunkDataWrite(const DMContext & dm_context, const GenPageId & gen_data_page_id, WriteBatch & wb, const Block & block);

dbms/src/Storages/DeltaMerge/ChunkBlockInputStream.h

@@ -17,7 +17,7 @@ class ChunkBlockInputStream final : public IBlockInputStream
                           const ColumnDefines & read_columns_,
                           const PageReader &    page_reader_,
                           const RSOperatorPtr & filter)
-        : chunks(chunks_), skip_chunks(chunks.size(), 0), read_columns(read_columns_), page_reader(page_reader_)
+        : chunks(std::move(chunks_)), skip_chunks(chunks.size(), 0), read_columns(read_columns_), page_reader(page_reader_)
     {
         if (filter)
         {

dbms/src/Storages/DeltaMerge/DMContext.h

@@ -30,6 +30,9 @@ struct DMContext
 
     const NotCompress & not_compress;
 
+    // The rows of segment.
+    const size_t segment_limit_rows;
+
     // The threshold of delta.
     const size_t delta_limit_rows;
     const size_t delta_limit_bytes;

dbms/src/Storages/DeltaMerge/DMSegmentThreadInputStream.h

@@ -13,9 +13,11 @@ class DMSegmentThreadInputStream : public IProfilingBlockInputStream
     /// If handle_real_type_ is empty, means do not convert handle column back to real type.
     DMSegmentThreadInputStream(const SegmentReadTaskPoolPtr & task_pool_,
                                const SegmentStreamCreator &   stream_creator_,
+                               const AfterSegmentRead &       after_segment_read_,
                                const ColumnDefines &          columns_to_read_)
         : task_pool(task_pool_),
           stream_creator(stream_creator_),
+          after_segment_read(after_segment_read_),
           columns_to_read(columns_to_read_),
           header(toEmptyBlock(columns_to_read)),
           log(&Logger::get("DMSegmentThreadInputStream"))
@@ -41,9 +43,9 @@ class DMSegmentThreadInputStream : public IProfilingBlockInputStream
                     return {};
                 }
 
-                cur_segment_id = task->segment->segmentId();
-                cur_stream     = stream_creator(*task);
-                LOG_TRACE(log, "Start to read segment [" + DB::toString(cur_segment_id) + "]");
+                cur_segment = task->segment;
+                cur_stream  = stream_creator(*task);
+                LOG_TRACE(log, "Start to read segment [" + DB::toString(cur_segment->segmentId()) + "]");
             }
 
             Block res = cur_stream->read();
@@ -56,9 +58,10 @@ class DMSegmentThreadInputStream : public IProfilingBlockInputStream
             }
             else
             {
-                LOG_TRACE(log, "Finish reading segment [" + DB::toString(cur_segment_id) + "]");
-                cur_segment_id = 0;
-                cur_stream     = {};
+                after_segment_read(cur_segment);
+                LOG_TRACE(log, "Finish reading segment [" + DB::toString(cur_segment->segmentId()) + "]");
+                cur_segment = {};
+                cur_stream  = {};
             }
         }
     }
@@ -74,12 +77,13 @@ class DMSegmentThreadInputStream : public IProfilingBlockInputStream
 private:
     SegmentReadTaskPoolPtr task_pool;
     SegmentStreamCreator   stream_creator;
+    AfterSegmentRead       after_segment_read;
     ColumnDefines          columns_to_read;
     Block                  header;
 
     bool                done = false;
     BlockInputStreamPtr cur_stream;
-    UInt64              cur_segment_id;
+    SegmentPtr          cur_segment;
 
     Logger * log;
 };

dbms/src/Storages/DeltaMerge/DeltaMerge.h

@@ -140,14 +140,14 @@ class DeltaMergeBlockInputStream final : public IProfilingBlockInputStream
 
         if constexpr (!c_delta_done)
         {
-            auto tuple_id = entry_it.getValue();
+            auto value = entry_it.getValue();
             switch (entry_it.getType())
             {
             case DT_DEL:
-                writeDeleteFromDelta(1);
+                writeDeleteFromDelta(value);
                 break;
             case DT_INS:
-                writeInsertFromDelta(output_columns, tuple_id);
+                writeInsertFromDelta(output_columns, value);
                 --output_write_limit;
                 break;
             default:
@@ -242,15 +242,15 @@ class DeltaMergeBlockInputStream final : public IProfilingBlockInputStream
             if (!stable_input_stream_raw_ptr->hasNext())
                 throw Exception("Unexpected end of block, need more rows to skip");
 
-            size_t rows = stable_input_stream_raw_ptr->nextRows();
-            if (!stable_input_stream_raw_ptr->shouldSkipNext())
+            ssize_t rows = stable_input_stream_raw_ptr->nextRows();
+            if (stable_skip > rows || stable_input_stream_raw_ptr->shouldSkipNext())
             {
-                fillStableBlockIfNeeded();
+                stable_input_stream_raw_ptr->skipNext();
+                stable_skip -= rows;
             }
             else
             {
-                stable_input_stream_raw_ptr->skipNext();
-                stable_skip -= rows;
+                fillStableBlockIfNeeded();
             }
         }
 
@@ -328,7 +328,7 @@ class DeltaMergeBlockInputStream final : public IProfilingBlockInputStream
     {
         auto prev_sid = entry_it.getSid();
         if (entry_it.getType() == DT_DEL)
-            prev_sid += 1;
+            prev_sid += entry_it.getValue();
 
         ++entry_it;
 

dbms/src/Storages/DeltaMerge/DeltaMergeDefines.h

@@ -86,7 +86,7 @@ using ColumnMap        = std::unordered_map<ColId, ColumnPtr>;
 using MutableColumnMap = std::unordered_map<ColId, MutableColumnPtr>;
 using LockGuard        = std::lock_guard<std::mutex>;
 
-static const UInt64 INITIAL_EPOCH = 5; // Following TiDB, and I have no idea why 5 is chosen.
+static const UInt64 INITIAL_EPOCH = 0;
 
 // TODO maybe we should use those variables instead of macros?
 #define EXTRA_HANDLE_COLUMN_NAME ::DB::MutableSupport::tidb_pk_column_name
@@ -129,8 +129,9 @@ static constexpr Handle P_INF_HANDLE = MAX_INT64; // Used in range, indicating p
 static_assert(static_cast<Int64>(static_cast<UInt64>(MIN_INT64)) == MIN_INT64, "Unsupported compiler!");
 static_assert(static_cast<Int64>(static_cast<UInt64>(MAX_INT64)) == MAX_INT64, "Unsupported compiler!");
 
-static constexpr UInt64 DEL_RANGE_POS_MARK = (1ULL << 63);
+static constexpr bool DM_RUN_CHECK = true;
 
+#define WARN_UNUSED_RESULT __attribute__((warn_unused_result))
 
 } // namespace DM
 } // namespace DB

dbms/src/Storages/DeltaMerge/DeltaMergeStore-internal.cpp

@@ -34,7 +34,7 @@ DeltaMergeStore::WriteActions prepareWriteActions(const Block &
                                                  : std::lower_bound(handle_data.cbegin() + offset, handle_data.cend(), range.end);
         size_t limit = end_pos - (handle_data.cbegin() + offset);
 
-        actions.emplace_back(DeltaMergeStore::WriteAction{.segment = segment, .offset = offset, .limit = limit});
+        actions.emplace_back(segment, offset, limit);
 
         offset += limit;
     }
@@ -54,10 +54,7 @@ DeltaMergeStore::WriteActions prepareWriteActions(const HandleRange &
     {
         (void)handle_;
         if (segment->getRange().intersect(delete_range))
-        {
-            // TODO maybe more precise on `action.update`
-            actions.emplace_back(DeltaMergeStore::WriteAction{.segment = segment, .offset = 0, .limit = 0, .update = delete_range});
-        }
+            actions.emplace_back(segment, delete_range);
     }
 
     return actions;