diff --git a/be/src/pipeline/exec/scan_operator.cpp b/be/src/pipeline/exec/scan_operator.cpp index b81a64c7dfe5fb..b7dc78bf8f1c1d 100644 --- a/be/src/pipeline/exec/scan_operator.cpp +++ b/be/src/pipeline/exec/scan_operator.cpp @@ -997,16 +997,7 @@ Status ScanLocalState::_start_scanners( auto& p = _parent->cast(); _scanner_ctx = vectorized::ScannerContext::create_shared( state(), this, p._output_tuple_desc, p.output_row_descriptor(), scanners, p.limit(), - state()->scan_queue_mem_limit(), _scan_dependency, - // NOTE: This will logic makes _max_thread_num of ScannerContext to be C(num of cores) * 2 - // For a query with C/2 instance and M scan node, scan task of this query will be C/2 * M * C*2 - // and will be C*C*N at most. - // 1. If data distribution is ignored , we use 1 instance to scan. - // 2. Else if this operator is not file scan operator, we use config::doris_scanner_thread_pool_thread_num scanners to scan. - // 3. Else, file scanner will consume much memory so we use config::doris_scanner_thread_pool_thread_num / query_parallel_instance_num scanners to scan. - p.ignore_data_distribution() || !p.is_file_scan_operator() - ? 1 - : state()->query_parallel_instance_num()); + _scan_dependency, p.ignore_data_distribution()); return Status::OK(); } diff --git a/be/src/vec/exec/scan/scanner_context.cpp b/be/src/vec/exec/scan/scanner_context.cpp index 276da7e09729ce..e93982a15482b4 100644 --- a/be/src/vec/exec/scan/scanner_context.cpp +++ b/be/src/vec/exec/scan/scanner_context.cpp @@ -23,16 +23,19 @@ #include #include +#include #include #include "common/config.h" #include "common/status.h" +#include "olap/tablet.h" #include "pipeline/exec/scan_operator.h" #include "runtime/descriptors.h" #include "runtime/exec_env.h" #include "runtime/runtime_state.h" #include "util/uid_util.h" #include "vec/core/block.h" +#include "vec/exec/scan/scanner_scheduler.h" #include "vec/exec/scan/vscan_node.h" namespace doris::vectorized { @@ -43,8 +46,7 @@ ScannerContext::ScannerContext( RuntimeState* state, pipeline::ScanLocalStateBase* local_state, const TupleDescriptor* output_tuple_desc, const RowDescriptor* output_row_descriptor, const std::list>& scanners, int64_t limit_, - int64_t max_bytes_in_blocks_queue, std::shared_ptr dependency, - const int num_parallel_instances) + std::shared_ptr dependency, bool ignore_data_distribution) : HasTaskExecutionCtx(state), _state(state), _local_state(local_state), @@ -54,53 +56,140 @@ ScannerContext::ScannerContext( _output_row_descriptor(output_row_descriptor), _batch_size(state->batch_size()), limit(limit_), - _max_bytes_in_queue(std::max(max_bytes_in_blocks_queue, (int64_t)1024) * - num_parallel_instances), - _scanner_scheduler(state->exec_env()->scanner_scheduler()), + _scanner_scheduler_global(state->exec_env()->scanner_scheduler()), _all_scanners(scanners.begin(), scanners.end()), - _num_parallel_instances(num_parallel_instances) { + _ignore_data_distribution(ignore_data_distribution) { DCHECK(_output_row_descriptor == nullptr || _output_row_descriptor->tuple_descriptors().size() == 1); _query_id = _state->get_query_ctx()->query_id(); ctx_id = UniqueId::gen_uid().to_string(); + _scanners.enqueue_bulk(scanners.begin(), scanners.size()); + if (limit < 0) { + limit = -1; + } + MAX_SCALE_UP_RATIO = _state->scanner_scale_up_ratio(); + _query_thread_context = {_query_id, _state->query_mem_tracker(), + _state->get_query_ctx()->workload_group()}; + _dependency = dependency; + + DorisMetrics::instance()->scanner_ctx_cnt->increment(1); +} + +// After init function call, should not access _parent +Status ScannerContext::init() { + _scanner_profile = _local_state->_scanner_profile; + _scanner_sched_counter = _local_state->_scanner_sched_counter; + _newly_create_free_blocks_num = _local_state->_newly_create_free_blocks_num; + _scanner_wait_batch_timer = _local_state->_scanner_wait_batch_timer; + _scanner_ctx_sched_time = _local_state->_scanner_ctx_sched_time; + _scale_up_scanners_counter = _local_state->_scale_up_scanners_counter; + +#ifndef BE_TEST + // 3. get thread token + if (!_state->get_query_ctx()) { + return Status::InternalError("Query context of {} is not set", + print_id(_state->query_id())); + } + + thread_token = _state->get_query_ctx()->get_token(); + + if (_state->get_query_ctx()->get_scan_scheduler()) { + _should_reset_thread_name = false; + } + +#endif + _local_state->_runtime_profile->add_info_string("UseSpecificThreadToken", + thread_token == nullptr ? "False" : "True"); + + const int num_parallel_instances = _state->query_parallel_instance_num(); + + // _max_bytes_in_queue controls the maximum memory that can be used by a single scan instance. + // scan_queue_mem_limit on FE is 100MB by default, on backend we will make sure its actual value + // is larger than 10MB. + _max_bytes_in_queue = std::max(_state->scan_queue_mem_limit(), (int64_t)1024 * 1024 * 10); + // Provide more memory for wide tables, increase proportionally by multiples of 300 _max_bytes_in_queue *= _output_tuple_desc->slots().size() / 300 + 1; - if (scanners.empty()) { + + // TODO: Where is the proper position to place this code? + if (_all_scanners.empty()) { _is_finished = true; _set_scanner_done(); } - _scanners.enqueue_bulk(scanners.begin(), scanners.size()); - if (limit < 0) { - limit = -1; + + // This is a track implementation. + // The logic is kept only for the purpose of the potential performance issue. + bool submit_many_scan_tasks_for_potential_performance_issue = true; + auto scanner = _all_scanners.front().lock(); + DCHECK(scanner != nullptr); + // A query could have remote scan task and local scan task at the same time. + // So we need to compute the _scanner_scheduler in each scan operator instead of query context. + SimplifiedScanScheduler* simple_scan_scheduler = _state->get_query_ctx()->get_scan_scheduler(); + SimplifiedScanScheduler* remote_scan_task_scheduler = + _state->get_query_ctx()->get_remote_scan_scheduler(); + if (scanner->_scanner->get_storage_type() == TabletStorageType::STORAGE_TYPE_LOCAL) { + // scan_scheduler could be empty if query does not have a workload group. + if (simple_scan_scheduler) { + _scanner_scheduler = simple_scan_scheduler; + } else { + _scanner_scheduler = _scanner_scheduler_global->get_local_scan_thread_pool(); + } + } else { + // remote_scan_task_scheduler could be empty if query does not have a workload group. + if (remote_scan_task_scheduler) { + _scanner_scheduler = remote_scan_task_scheduler; + } else { + _scanner_scheduler = _scanner_scheduler_global->get_remote_scan_thread_pool(); + } } - MAX_SCALE_UP_RATIO = _state->scanner_scale_up_ratio(); + + if (_scanner_scheduler->get_queue_size() * 2 > config::doris_scanner_thread_pool_queue_size) { + submit_many_scan_tasks_for_potential_performance_issue = false; + } + // _max_thread_num controls how many scanners of this ScanOperator can be submitted to scheduler at a time. // The overall target of our system is to make full utilization of the resources. - // At the same time, we dont want too many tasks are queued by scheduler, that makes the query - // waiting too long, and existing task can not be scheduled in time. - // First of all, we try to make sure _max_thread_num of a ScanNode of a query on a single backend is less than - // config::doris_scanner_thread_pool_thread_num. + // At the same time, we dont want too many tasks are queued by scheduler, that is not necessary. + // So, first of all, we try to make sure _max_thread_num of a ScanNode of a query on a single backend is less than + // 2 * config::doris_scanner_thread_pool_thread_num, so that we can make all io threads busy. // For example, on a 64-core machine, the default value of config::doris_scanner_thread_pool_thread_num will be 64*2 =128. // and the num_parallel_instances of this scan operator will be 64/2=32. - // For a query who has two scan nodes, the _max_thread_num of each scan node instance will be 128 / 32 = 4. - // We have 32 instances of this scan operator, so for the ScanNode, we have 4 * 32 = 128 scanner tasks can be submitted at a time. - // Remember that we have to ScanNode in this query, so the total number of scanner tasks can be submitted at a time is 128 * 2 = 256. - _max_thread_num = - _state->num_scanner_threads() > 0 - ? _state->num_scanner_threads() - : config::doris_scanner_thread_pool_thread_num / num_parallel_instances; + // For a query who has one scan nodes, the _max_thread_num of each scan node instance will be 4 * 128 / 32 = 16. + // We have 32 instances of this scan operator, so for the ScanNode, we have 16 * 32 = 8 * 64 = 512 scanner tasks can be submitted at a time. + _max_thread_num = _state->num_scanner_threads() > 0 ? _state->num_scanner_threads() : 0; + + if (_max_thread_num == 0) { + // NOTE: When ignore_data_distribution is true, the parallelism + // of the scan operator is regarded as 1 (actually maybe not). + // That will make the number of scan task can be submitted to the scheduler + // in a vary large value. This logicl is kept from the older implementation. + if (submit_many_scan_tasks_for_potential_performance_issue || _ignore_data_distribution) { + _max_thread_num = config::doris_scanner_thread_pool_thread_num / 1; + } else { + _max_thread_num = + 4 * (config::doris_scanner_thread_pool_thread_num / num_parallel_instances); + // In some rare cases, user may set num_parallel_instances to 1 handly to make many query could be executed + // in parallel. We need to make sure the _max_thread_num is smaller than previous value. + _max_thread_num = + std::min(_max_thread_num, config::doris_scanner_thread_pool_thread_num); + } + } + _max_thread_num = _max_thread_num == 0 ? 1 : _max_thread_num; // In some situation, there are not too many big tablets involed, so we can reduce the thread number. - _max_thread_num = std::min(_max_thread_num, (int32_t)scanners.size()); + // NOTE: when _all_scanners.size is zero, the _max_thread_num will be 0. + _max_thread_num = std::min(_max_thread_num, (int32_t)_all_scanners.size()); + // 1. Calculate max concurrency // For select * from table limit 10; should just use one thread. if (_local_state->should_run_serial()) { _max_thread_num = 1; } + // when user not specify scan_thread_num, so we can try downgrade _max_thread_num. // becaue we found in a table with 5k columns, column reader may ocuppy too much memory. // you can refer https://github.com/apache/doris/issues/35340 for details. - int32_t max_column_reader_num = state->query_options().max_column_reader_num; + int32_t max_column_reader_num = _state->query_options().max_column_reader_num; if (_max_thread_num != 1 && max_column_reader_num > 0) { int32_t scan_column_num = _output_tuple_desc->slots().size(); int32_t current_column_num = scan_column_num * _max_thread_num; @@ -110,7 +199,7 @@ ScannerContext::ScannerContext( if (new_max_thread_num < _max_thread_num) { int32_t origin_max_thread_num = _max_thread_num; _max_thread_num = new_max_thread_num; - LOG(INFO) << "downgrade query:" << print_id(state->query_id()) + LOG(INFO) << "downgrade query:" << print_id(_state->query_id()) << " scan's max_thread_num from " << origin_max_thread_num << " to " << _max_thread_num << ",column num: " << scan_column_num << ", max_column_reader_num: " << max_column_reader_num; @@ -118,38 +207,7 @@ ScannerContext::ScannerContext( } } - _query_thread_context = {_query_id, _state->query_mem_tracker(), - _state->get_query_ctx()->workload_group()}; - _dependency = dependency; - - DorisMetrics::instance()->scanner_ctx_cnt->increment(1); -} - -// After init function call, should not access _parent -Status ScannerContext::init() { - _scanner_profile = _local_state->_scanner_profile; - _scanner_sched_counter = _local_state->_scanner_sched_counter; - _newly_create_free_blocks_num = _local_state->_newly_create_free_blocks_num; - _scanner_wait_batch_timer = _local_state->_scanner_wait_batch_timer; - _scanner_ctx_sched_time = _local_state->_scanner_ctx_sched_time; - _scale_up_scanners_counter = _local_state->_scale_up_scanners_counter; - _scanner_memory_used_counter = _local_state->_memory_used_counter; - -#ifndef BE_TEST - // 3. get thread token - if (_state->get_query_ctx()) { - thread_token = _state->get_query_ctx()->get_token(); - _simple_scan_scheduler = _state->get_query_ctx()->get_scan_scheduler(); - if (_simple_scan_scheduler) { - _should_reset_thread_name = false; - } - _remote_scan_task_scheduler = _state->get_query_ctx()->get_remote_scan_scheduler(); - } -#endif - COUNTER_SET(_local_state->_max_scanner_thread_num, (int64_t)_max_thread_num); - _local_state->_runtime_profile->add_info_string("UseSpecificThreadToken", - thread_token == nullptr ? "False" : "True"); // submit `_max_thread_num` running scanners to `ScannerScheduler` // When a running scanners is finished, it will submit one of the remaining scanners. @@ -205,7 +263,7 @@ bool ScannerContext::empty_in_queue(int id) { Status ScannerContext::submit_scan_task(std::shared_ptr scan_task) { _scanner_sched_counter->update(1); _num_scheduled_scanners++; - return _scanner_scheduler->submit(shared_from_this(), scan_task); + return _scanner_scheduler_global->submit(shared_from_this(), scan_task); } void ScannerContext::append_block_to_queue(std::shared_ptr scan_task) { diff --git a/be/src/vec/exec/scan/scanner_context.h b/be/src/vec/exec/scan/scanner_context.h index 4dcb9db610e7ca..85669765df89ef 100644 --- a/be/src/vec/exec/scan/scanner_context.h +++ b/be/src/vec/exec/scan/scanner_context.h @@ -107,9 +107,8 @@ class ScannerContext : public std::enable_shared_from_this, const TupleDescriptor* output_tuple_desc, const RowDescriptor* output_row_descriptor, const std::list>& scanners, - int64_t limit_, int64_t max_bytes_in_blocks_queue, - std::shared_ptr dependency, - const int num_parallel_instances); + int64_t limit_, std::shared_ptr dependency, + bool ignore_data_distribution); ~ScannerContext() override { SCOPED_SWITCH_THREAD_MEM_TRACKER_LIMITER(_query_thread_context.query_mem_tracker); @@ -162,9 +161,7 @@ class ScannerContext : public std::enable_shared_from_this, bool empty_in_queue(int id); - SimplifiedScanScheduler* get_simple_scan_scheduler() { return _simple_scan_scheduler; } - - SimplifiedScanScheduler* get_remote_scan_scheduler() { return _remote_scan_task_scheduler; } + SimplifiedScanScheduler* get_scan_scheduler() { return _scanner_scheduler; } void stop_scanners(RuntimeState* state); @@ -212,17 +209,15 @@ class ScannerContext : public std::enable_shared_from_this, int64_t limit; int32_t _max_thread_num = 0; - int64_t _max_bytes_in_queue; - doris::vectorized::ScannerScheduler* _scanner_scheduler; - SimplifiedScanScheduler* _simple_scan_scheduler = nullptr; - SimplifiedScanScheduler* _remote_scan_task_scheduler = nullptr; + int64_t _max_bytes_in_queue = 0; + doris::vectorized::ScannerScheduler* _scanner_scheduler_global = nullptr; + SimplifiedScanScheduler* _scanner_scheduler = nullptr; moodycamel::ConcurrentQueue> _scanners; int32_t _num_scheduled_scanners = 0; int32_t _num_finished_scanners = 0; int32_t _num_running_scanners = 0; // weak pointer for _scanners, used in stop function std::vector> _all_scanners; - const int _num_parallel_instances; std::shared_ptr _scanner_profile; RuntimeProfile::Counter* _scanner_sched_counter = nullptr; // This counter refers to scan operator's local state @@ -233,6 +228,7 @@ class ScannerContext : public std::enable_shared_from_this, RuntimeProfile::Counter* _scale_up_scanners_counter = nullptr; QueryThreadContext _query_thread_context; std::shared_ptr _dependency = nullptr; + bool _ignore_data_distribution = false; // for scaling up the running scanners size_t _estimated_block_size = 0; diff --git a/be/src/vec/exec/scan/scanner_scheduler.cpp b/be/src/vec/exec/scan/scanner_scheduler.cpp index 23ed5db0798351..3ad4e758e79980 100644 --- a/be/src/vec/exec/scan/scanner_scheduler.cpp +++ b/be/src/vec/exec/scan/scanner_scheduler.cpp @@ -170,13 +170,7 @@ Status ScannerScheduler::submit(std::shared_ptr ctx, scanner_delegate->_scanner->start_wait_worker_timer(); TabletStorageType type = scanner_delegate->_scanner->get_storage_type(); auto sumbit_task = [&]() { - bool is_local = type == TabletStorageType::STORAGE_TYPE_LOCAL; - SimplifiedScanScheduler* scan_sched = - is_local ? ctx->get_simple_scan_scheduler() : ctx->get_remote_scan_scheduler(); - if (!scan_sched) { // query without workload group - scan_sched = - is_local ? _local_scan_thread_pool.get() : _remote_scan_thread_pool.get(); - } + SimplifiedScanScheduler* scan_sched = ctx->get_scan_scheduler(); auto work_func = [scanner_ref = scan_task, ctx]() { DorisMetrics::instance()->scanner_task_queued->increment(-1); DorisMetrics::instance()->scanner_task_running->increment(1); diff --git a/be/src/vec/exec/scan/scanner_scheduler.h b/be/src/vec/exec/scan/scanner_scheduler.h index f832e348088cdb..56c49368598adc 100644 --- a/be/src/vec/exec/scan/scanner_scheduler.h +++ b/be/src/vec/exec/scan/scanner_scheduler.h @@ -72,6 +72,12 @@ class ScannerScheduler { static int get_remote_scan_thread_queue_size(); + SimplifiedScanScheduler* get_local_scan_thread_pool() { return _local_scan_thread_pool.get(); } + + SimplifiedScanScheduler* get_remote_scan_thread_pool() { + return _remote_scan_thread_pool.get(); + } + private: static void _scanner_scan(std::shared_ptr ctx, std::shared_ptr scan_task); diff --git a/fe/fe-core/src/main/java/org/apache/doris/qe/SessionVariable.java b/fe/fe-core/src/main/java/org/apache/doris/qe/SessionVariable.java index 638ea712ce99d1..d59d40727dbc25 100644 --- a/fe/fe-core/src/main/java/org/apache/doris/qe/SessionVariable.java +++ b/fe/fe-core/src/main/java/org/apache/doris/qe/SessionVariable.java @@ -696,7 +696,10 @@ public class SessionVariable implements Serializable, Writable { @VariableMgr.VarAttr(name = EXEC_MEM_LIMIT) public long maxExecMemByte = 2147483648L; - @VariableMgr.VarAttr(name = SCAN_QUEUE_MEM_LIMIT) + @VariableMgr.VarAttr(name = SCAN_QUEUE_MEM_LIMIT, + description = {"每个 Scan Instance 的 block queue 能够保存多少字节的 block", + "How many bytes of block can be saved in the block queue of each Scan Instance"}) + // 100MB public long maxScanQueueMemByte = 2147483648L / 20; @VariableMgr.VarAttr(name = NUM_SCANNER_THREADS, needForward = true, description = {