TiFlash supports stale read

dbms/src/Common/TiFlashMetrics.h

@@ -105,6 +105,7 @@ namespace DB
     M(tiflash_schema_apply_duration_seconds, "Bucketed histogram of ddl apply duration", Histogram,                                       \
         F(type_ddl_apply_duration, {{"req", "ddl_apply_duration"}}, ExpBuckets{0.001, 2, 20}))                                            \
     M(tiflash_raft_read_index_count, "Total number of raft read index", Counter)                                                          \
+    M(tiflash_stale_read_count, "Total number of stale read", Counter)                                                                    \
     M(tiflash_raft_read_index_duration_seconds, "Bucketed histogram of raft read index duration", Histogram,                              \
         F(type_raft_read_index_duration, {{"type", "tmt_raft_read_index_duration"}}, ExpBuckets{0.001, 2, 20}))                           \
     M(tiflash_raft_wait_index_duration_seconds, "Bucketed histogram of raft wait index duration", Histogram,                              \

dbms/src/Debug/DAGProperties.h

@@ -29,6 +29,11 @@ struct DAGProperties
     bool use_broadcast_join = false;
     Int32 mpp_partition_num = 1;
     Timestamp start_ts = DEFAULT_MAX_READ_TSO;
+    UInt64 query_ts = 0;
+    UInt64 server_id = 1;
+    UInt64 local_query_id = 1;
+    Int64 task_id = 1;
+
     Int32 mpp_timeout = 10;
 };
 } // namespace DB

dbms/src/Debug/MockComputeServerManager.cpp

@@ -115,11 +115,14 @@ void MockComputeServerManager::addServer(size_t partition_id, std::unique_ptr<Fl
     server_map[partition_id] = std::move(server);
 }
 
-void MockComputeServerManager::cancelQuery(size_t start_ts)
+void MockComputeServerManager::cancelQuery(const MPPQueryId & query_id)
 {
     mpp::CancelTaskRequest req;
     auto * meta = req.mutable_meta();
-    meta->set_start_ts(start_ts);
+    meta->set_query_ts(query_id.query_ts);
+    meta->set_local_query_id(query_id.local_query_id);
+    meta->set_server_id(query_id.server_id);
+    meta->set_start_ts(query_id.start_ts);
     mpp::CancelTaskResponse response;
     for (const auto & server : server_map)
         server.second->flashService()->cancelMPPTaskForTest(&req, &response);

dbms/src/Debug/MockComputeServerManager.h

@@ -22,7 +22,6 @@
 
 namespace DB::tests
 {
-
 /** Hold Mock Compute Server to manage the lifetime of them.
   * Maintains Mock Compute Server info.
   */
@@ -49,7 +48,7 @@ class MockComputeServerManager : public ext::Singleton<MockComputeServerManager>
 
     void resetMockMPPServerInfo(size_t partition_num);
 
-    void cancelQuery(size_t start_ts);
+    void cancelQuery(const MPPQueryId & query_id);
 
     static String queryInfo();
 

dbms/src/Debug/MockExecutor/AstToPB.h

@@ -57,18 +57,27 @@ using MPPCtxPtr = std::shared_ptr<MPPCtx>;
 struct MPPInfo
 {
     Timestamp start_ts;
+    UInt64 query_ts;
+    UInt64 server_id;
+    UInt64 local_query_id;
     Int64 partition_id;
     Int64 task_id;
     const std::vector<Int64> sender_target_task_ids;
     const std::unordered_map<String, std::vector<Int64>> receiver_source_task_ids_map;
 
     MPPInfo(
         Timestamp start_ts_,
+        UInt64 query_ts_,
+        UInt64 server_id_,
+        UInt64 local_query_id_,
         Int64 partition_id_,
         Int64 task_id_,
         const std::vector<Int64> & sender_target_task_ids_,
         const std::unordered_map<String, std::vector<Int64>> & receiver_source_task_ids_map_)
         : start_ts(start_ts_)
+        , query_ts(query_ts_)
+        , server_id(server_id_)
+        , local_query_id(local_query_id_)
         , partition_id(partition_id_)
         , task_id(task_id_)
         , sender_target_task_ids(sender_target_task_ids_)

dbms/src/Debug/MockExecutor/ExchangeReceiverBinder.cpp

@@ -42,6 +42,9 @@ bool ExchangeReceiverBinder::toTiPBExecutor(tipb::Executor * tipb_executor, int3
     {
         mpp::TaskMeta meta;
         meta.set_start_ts(mpp_info.start_ts);
+        meta.set_query_ts(mpp_info.query_ts);
+        meta.set_server_id(mpp_info.server_id);
+        meta.set_local_query_id(mpp_info.local_query_id);
         meta.set_task_id(it->second[i]);
         meta.set_partition_id(i);
         auto addr = context.isMPPTest() ? tests::MockComputeServerManager::instance().getServerConfigMap()[i].addr : Debug::LOCAL_HOST;

dbms/src/Debug/MockExecutor/ExchangeSenderBinder.cpp

@@ -41,6 +41,9 @@ bool ExchangeSenderBinder::toTiPBExecutor(tipb::Executor * tipb_executor, int32_
     {
         mpp::TaskMeta meta;
         meta.set_start_ts(mpp_info.start_ts);
+        meta.set_query_ts(mpp_info.query_ts);
+        meta.set_server_id(mpp_info.server_id);
+        meta.set_local_query_id(mpp_info.local_query_id);
         meta.set_task_id(task_id);
         meta.set_partition_id(i);
         auto addr = context.isMPPTest() ? tests::MockComputeServerManager::instance().getServerConfigMap()[i++].addr : Debug::LOCAL_HOST;

dbms/src/Debug/dbgFuncMisc.cpp

@@ -29,8 +29,8 @@ inline size_t getReadTSOForLog(const String & line)
     {
         std::regex rx(R"((0|[1-9][0-9]*))");
         std::smatch m;
-        // Rely on that MPP task prefix "MPP<query:435802637197639681,task:1>"
-        auto pos = line.find("query:");
+        // Rely on that MPP task prefix "MPP<query:<query_ts:1671124209981679458, local_query_id:42578432, server_id:3340035, start_ts:438075169172357120>,task_id:42578433>"
+        auto pos = line.find(", start_ts:");
         if (pos != std::string::npos && regex_search(line.cbegin() + pos, line.cend(), m, rx))
         {
             return std::stoul(m[1]);

dbms/src/Debug/dbgQueryCompiler.h

@@ -132,6 +132,9 @@ struct QueryFragment
             {
                 MPPInfo mpp_info(
                     properties.start_ts,
+                    properties.query_ts,
+                    properties.server_id,
+                    properties.local_query_id,
                     partition_id,
                     task_ids[partition_id],
                     sender_target_task_ids,
@@ -141,7 +144,7 @@ struct QueryFragment
         }
         else
         {
-            MPPInfo mpp_info(properties.start_ts, /*partition_id*/ -1, /*task_id*/ -1, /*sender_target_task_ids*/ {}, /*receiver_source_task_ids_map*/ {});
+            MPPInfo mpp_info(properties.start_ts, properties.query_ts, properties.server_id, properties.local_query_id, /*partition_id*/ -1, /*task_id*/ -1, /*sender_target_task_ids*/ {}, /*receiver_source_task_ids_map*/ {});
             ret.push_back(toQueryTask(properties, mpp_info, context));
         }
         return ret;

dbms/src/Debug/dbgQueryExecutor.cpp

@@ -42,6 +42,9 @@ BlockInputStreamPtr constructExchangeReceiverStream(Context & context, tipb::Exc
 
     mpp::TaskMeta root_tm;
     root_tm.set_start_ts(properties.start_ts);
+    root_tm.set_query_ts(properties.query_ts);
+    root_tm.set_local_query_id(properties.local_query_id);
+    root_tm.set_server_id(properties.server_id);
     root_tm.set_address(root_addr);
     root_tm.set_task_id(-1);
     root_tm.set_partition_id(-1);
@@ -71,6 +74,9 @@ BlockInputStreamPtr prepareRootExchangeReceiver(Context & context, const DAGProp
     {
         mpp::TaskMeta tm;
         tm.set_start_ts(properties.start_ts);
+        tm.set_query_ts(properties.query_ts);
+        tm.set_local_query_id(properties.local_query_id);
+        tm.set_server_id(properties.server_id);
         tm.set_address(Debug::LOCAL_HOST);
         tm.set_task_id(root_task_id);
         tm.set_partition_id(-1);
@@ -84,6 +90,9 @@ void prepareExchangeReceiverMetaWithMultipleContext(tipb::ExchangeReceiver & tip
 {
     mpp::TaskMeta tm;
     tm.set_start_ts(properties.start_ts);
+    tm.set_query_ts(properties.query_ts);
+    tm.set_local_query_id(properties.local_query_id);
+    tm.set_server_id(properties.server_id);
     tm.set_address(addr);
     tm.set_task_id(task_id);
     tm.set_partition_id(-1);
@@ -109,6 +118,9 @@ void prepareDispatchTaskRequest(QueryTask & task, std::shared_ptr<mpp::DispatchT
     }
     auto * tm = req->mutable_meta();
     tm->set_start_ts(properties.start_ts);
+    tm->set_query_ts(properties.query_ts);
+    tm->set_local_query_id(properties.local_query_id);
+    tm->set_server_id(properties.server_id);
     tm->set_partition_id(task.partition_id);
     tm->set_address(addr);
     tm->set_task_id(task.task_id);
@@ -128,6 +140,9 @@ void prepareDispatchTaskRequestWithMultipleContext(QueryTask & task, std::shared
     }
     auto * tm = req->mutable_meta();
     tm->set_start_ts(properties.start_ts);
+    tm->set_query_ts(properties.query_ts);
+    tm->set_local_query_id(properties.local_query_id);
+    tm->set_server_id(properties.server_id);
     tm->set_partition_id(task.partition_id);
     tm->set_address(addr);
     tm->set_task_id(task.task_id);

dbms/src/Flash/Coprocessor/DAGContext.h

@@ -158,7 +158,7 @@ class DAGContext
         , flags(dag_request->flags())
         , sql_mode(dag_request->sql_mode())
         , mpp_task_meta(meta_)
-        , mpp_task_id(mpp_task_meta.start_ts(), mpp_task_meta.task_id())
+        , mpp_task_id(mpp_task_meta)
         , max_recorded_error_count(getMaxErrorCount(*dag_request))
         , warnings(max_recorded_error_count)
         , warning_count(0)

dbms/src/Flash/FlashService.cpp

@@ -365,7 +365,7 @@ grpc::Status FlashService::CancelMPPTask(
 
     auto & tmt_context = context->getTMTContext();
     auto task_manager = tmt_context.getMPPTaskManager();
-    task_manager->abortMPPQuery(request->meta().start_ts(), "Receive cancel request from TiDB", AbortType::ONCANCELLATION);
+    task_manager->abortMPPQuery(MPPQueryId(request->meta()), "Receive cancel request from TiDB", AbortType::ONCANCELLATION);
     return grpc::Status::OK;
 }
 
@@ -407,7 +407,7 @@ ::grpc::Status FlashService::cancelMPPTaskForTest(const ::mpp::CancelTaskRequest
     }
     auto & tmt_context = context->getTMTContext();
     auto task_manager = tmt_context.getMPPTaskManager();
-    task_manager->abortMPPQuery(request->meta().start_ts(), "Receive cancel request from GTest", AbortType::ONCANCELLATION);
+    task_manager->abortMPPQuery(MPPQueryId(request->meta()), "Receive cancel request from GTest", AbortType::ONCANCELLATION);
     return grpc::Status::OK;
 }
 

dbms/src/Flash/Mpp/MPPTask.cpp

@@ -54,7 +54,7 @@ extern const char force_no_local_region_for_mpp_task[];
 
 MPPTask::MPPTask(const mpp::TaskMeta & meta_, const ContextPtr & context_)
     : meta(meta_)
-    , id(meta.start_ts(), meta.task_id())
+    , id(meta)
     , context(context_)
     , manager(context_->getTMTContext().getMPPTaskManager().get())
     , schedule_entry(manager, id)
@@ -137,7 +137,7 @@ void MPPTask::registerTunnels(const mpp::DispatchTaskRequest & task_request)
         LOG_DEBUG(log, "begin to register the tunnel {}, is_local: {}, is_async: {}", tunnel->id(), is_local, is_async);
         if (status != INITIALIZING)
             throw Exception(fmt::format("The tunnel {} can not be registered, because the task is not in initializing state", tunnel->id()));
-        tunnel_set_local->registerTunnel(MPPTaskId{task_meta.start_ts(), task_meta.task_id()}, tunnel);
+        tunnel_set_local->registerTunnel(MPPTaskId(task_meta), tunnel);
         if (!dag_context->isRootMPPTask())
         {
             FAIL_POINT_TRIGGER_EXCEPTION(FailPoints::exception_during_mpp_register_tunnel_for_non_root_mpp_task);
@@ -202,7 +202,7 @@ std::pair<MPPTunnelPtr, String> MPPTask::getTunnel(const ::mpp::EstablishMPPConn
         return {nullptr, err_msg};
     }
 
-    MPPTaskId receiver_id{request->receiver_meta().start_ts(), request->receiver_meta().task_id()};
+    MPPTaskId receiver_id(request->receiver_meta());
     RUNTIME_ASSERT(tunnel_set != nullptr, log, "mpp task without tunnel set");
     auto tunnel_ptr = tunnel_set->getTunnelByReceiverTaskId(receiver_id);
     if (tunnel_ptr == nullptr)
@@ -450,7 +450,7 @@ void MPPTask::runImpl()
 void MPPTask::handleError(const String & error_msg)
 {
     auto updated_msg = fmt::format("From {}: {}", id.toString(), error_msg);
-    manager->abortMPPQuery(id.start_ts, updated_msg, AbortType::ONERROR);
+    manager->abortMPPQuery(id.query_id, updated_msg, AbortType::ONERROR);
     if (!registered)
         // if the task is not registered, need to cancel it explicitly
         abort(error_msg, AbortType::ONERROR);

dbms/src/Flash/Mpp/MPPTaskId.cpp

@@ -13,19 +13,91 @@
 // limitations under the License.
 
 #include <Flash/Mpp/MPPTaskId.h>
+#include <common/likely.h>
 #include <fmt/core.h>
 
 namespace DB
 {
+bool isOldVersion(const MPPQueryId & mpp_query_id)
+{
+    return mpp_query_id.query_ts == 0 && mpp_query_id.local_query_id == 0 && mpp_query_id.server_id == 0;
+}
+
+
+bool MPPQueryId::operator<(const MPPQueryId & mpp_query_id) const
+{
+    // compare with MPP query generated by TiDB that version less than v6.6
+    bool left_old_version = isOldVersion(*this);
+    bool right_old_version = isOldVersion(mpp_query_id);
+    if (unlikely(left_old_version && right_old_version))
+    {
+        return start_ts < mpp_query_id.start_ts;
+    }
+    if (unlikely(left_old_version))
+    {
+        return true;
+    }
+    if (unlikely(right_old_version))
+    {
+        return false;
+    }
+    // compare with MPP query generated by TiDB that version after v6.6
+    if (query_ts != mpp_query_id.query_ts)
+    {
+        return query_ts < mpp_query_id.query_ts;
+    }
+    if (server_id == mpp_query_id.server_id)
+    {
+        return local_query_id < mpp_query_id.local_query_id;
+    }
+    // now we can't compare reasonably, just choose one randomly by hash.
+    auto lhash = MPPQueryIdHash()(*this);
+    auto rhash = MPPQueryIdHash()(mpp_query_id);
+    if (lhash != rhash)
+    {
+        return lhash < rhash;
+    }
+    // hash values are same, just compare the rest fields.
+    if (local_query_id != mpp_query_id.local_query_id)
+    {
+        return local_query_id < mpp_query_id.local_query_id;
+    }
+    return server_id < mpp_query_id.server_id;
+}
+bool MPPQueryId::operator==(const MPPQueryId & rid) const
+{
+    return query_ts == rid.query_ts && local_query_id == rid.local_query_id && server_id == rid.server_id && start_ts == rid.start_ts;
+}
+bool MPPQueryId::operator!=(const MPPQueryId & rid) const
+{
+    return !(*this == rid);
+}
+bool MPPQueryId::operator<=(const MPPQueryId & rid) const
+{
+    return *this < rid || *this == rid;
+}
+
+size_t MPPQueryIdHash::operator()(MPPQueryId const & mpp_query_id) const noexcept
+{
+    if (unlikely(isOldVersion(mpp_query_id)))
+    {
+        return std::hash<UInt64>()(mpp_query_id.start_ts);
+    }
+    return std::hash<UInt64>()(mpp_query_id.query_ts) ^ std::hash<UInt64>()(mpp_query_id.local_query_id) ^ std::hash<UInt64>()(mpp_query_id.server_id);
+}
+
 String MPPTaskId::toString() const
 {
-    return isUnknown() ? "MPP<query:N/A,task:N/A>" : fmt::format("MPP<query:{},task:{}>", start_ts, task_id);
+    return isUnknown() ? "MPP<query_id:N/A,task_id:N/A>" : fmt::format("MPP<query:{},task_id:{}>", query_id.toString(), task_id);
 }
 
 const MPPTaskId MPPTaskId::unknown_mpp_task_id = MPPTaskId{};
 
+constexpr UInt64 MAX_UINT64 = std::numeric_limits<UInt64>::max();
+const MPPQueryId MPPTaskId::Max_Query_Id = MPPQueryId(MAX_UINT64, MAX_UINT64, MAX_UINT64, MAX_UINT64);
+
 bool operator==(const MPPTaskId & lid, const MPPTaskId & rid)
 {
-    return lid.start_ts == rid.start_ts && lid.task_id == rid.task_id;
+    return lid.query_id == rid.query_id && lid.task_id == rid.task_id;
 }
 } // namespace DB