diff --git a/be/src/pipeline/exec/scan_operator.cpp b/be/src/pipeline/exec/scan_operator.cpp index b2a38a1d84678a..cd65d61f641cda 100644 --- a/be/src/pipeline/exec/scan_operator.cpp +++ b/be/src/pipeline/exec/scan_operator.cpp @@ -994,7 +994,16 @@ 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(), - _scan_dependency, p.ignore_data_distribution()); + 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()); return Status::OK(); } diff --git a/be/src/vec/exec/scan/scanner_context.cpp b/be/src/vec/exec/scan/scanner_context.cpp index b5cb47fda1bdf5..cbb3d0f572365b 100644 --- a/be/src/vec/exec/scan/scanner_context.cpp +++ b/be/src/vec/exec/scan/scanner_context.cpp @@ -42,7 +42,8 @@ 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_, - std::shared_ptr dependency, bool ignore_data_distribution) + int64_t max_bytes_in_blocks_queue, std::shared_ptr dependency, + const int num_parallel_instances) : HasTaskExecutionCtx(state), _state(state), _local_state(local_state), @@ -52,102 +53,53 @@ 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()), _all_scanners(scanners.begin(), scanners.end()), - _ignore_data_distribution(ignore_data_distribution) { + _num_parallel_instances(num_parallel_instances) { 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; -} - -// 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()) { - 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 - _local_state->_runtime_profile->add_info_string("UseSpecificThreadToken", - thread_token == nullptr ? "False" : "True"); - - int num_parallel_instances = _state->query_parallel_instance_num(); - - // 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. - // https://github.com/apache/doris/pull/28266 - if (_ignore_data_distribution) { - num_parallel_instances = 1; - } - - // _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; - - // TODO: Where is the proper position to place this code? - if (_all_scanners.empty()) { + if (scanners.empty()) { _is_finished = true; _set_scanner_done(); } - + _scanners.enqueue_bulk(scanners.begin(), scanners.size()); + if (limit < 0) { + limit = -1; + } + MAX_SCALE_UP_RATIO = _state->scanner_scale_up_ratio(); // _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 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. + // 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. // 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 one scan nodes, the _max_thread_num of each scan node instance will be 2 * 128 / 32 = 8. - // We have 32 instances of this scan operator, so for the ScanNode, we have 8 * 32 = 256 scanner tasks can be submitted at a time. - // The thread pool of scanner is 128, that means we will have 128 tasks running in parallel and another 128 tasks are waiting in the queue. - // When first 128 tasks are finished, the next 128 tasks will be extricated from the queue and be executed, - // and another 128 tasks will be submitted to the queue if there are remaining. + // 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() - : 2 * (config::doris_scanner_thread_pool_thread_num / num_parallel_instances); + : config::doris_scanner_thread_pool_thread_num / num_parallel_instances; _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. - // 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()); - + _max_thread_num = std::min(_max_thread_num, (int32_t)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; @@ -157,7 +109,7 @@ Status ScannerContext::init() { 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; @@ -165,7 +117,35 @@ Status ScannerContext::init() { } } + _query_thread_context = {_query_id, _state->query_mem_tracker(), + _state->get_query_ctx()->workload_group()}; + _dependency = dependency; +} + +// 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()) { + 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. diff --git a/be/src/vec/exec/scan/scanner_context.h b/be/src/vec/exec/scan/scanner_context.h index 36eb20c220def4..03c4e5a4f1bba7 100644 --- a/be/src/vec/exec/scan/scanner_context.h +++ b/be/src/vec/exec/scan/scanner_context.h @@ -105,8 +105,9 @@ 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_, std::shared_ptr dependency, - bool ignore_data_distribution); + int64_t limit_, int64_t max_bytes_in_blocks_queue, + std::shared_ptr dependency, + const int num_parallel_instances); ~ScannerContext() override { SCOPED_SWITCH_THREAD_MEM_TRACKER_LIMITER(_query_thread_context.query_mem_tracker); @@ -209,7 +210,7 @@ class ScannerContext : public std::enable_shared_from_this, int64_t limit; int32_t _max_thread_num = 0; - int64_t _max_bytes_in_queue = 0; + int64_t _max_bytes_in_queue; doris::vectorized::ScannerScheduler* _scanner_scheduler; SimplifiedScanScheduler* _simple_scan_scheduler = nullptr; SimplifiedScanScheduler* _remote_scan_task_scheduler = nullptr; @@ -219,6 +220,7 @@ class ScannerContext : public std::enable_shared_from_this, 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; RuntimeProfile::Counter* _newly_create_free_blocks_num = nullptr; @@ -227,7 +229,6 @@ 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/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 9370a19cb79f34..22223def27c565 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 @@ -685,10 +685,7 @@ public class SessionVariable implements Serializable, Writable { @VariableMgr.VarAttr(name = EXEC_MEM_LIMIT) public long maxExecMemByte = 2147483648L; - @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 + @VariableMgr.VarAttr(name = SCAN_QUEUE_MEM_LIMIT) public long maxScanQueueMemByte = 2147483648L / 20; @VariableMgr.VarAttr(name = NUM_SCANNER_THREADS, needForward = true, description = {