/* Copyright (c) 2011, 2019, Oracle and/or its affiliates. All rights reserved. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License, version 2.0, as published by the Free Software Foundation. This program is also distributed with certain software (including but not limited to OpenSSL) that is licensed under separate terms, as designated in a particular file or component or in included license documentation. The authors of MySQL hereby grant you an additional permission to link the program and your derivative works with the separately licensed software that they have included with MySQL. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License, version 2.0, for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */ #include "sql/rpl_rli_pdb.h" #include "my_config.h" #include #ifdef HAVE_SYS_TIME_H #include #endif #include #include #include #include #include #include #include #include "lex_string.h" #include "m_string.h" #include "map_helpers.h" #include "my_bitmap.h" #include "my_compiler.h" #include "my_dbug.h" #include "my_sys.h" #include "my_systime.h" #include "my_thread.h" #include "mysql/components/services/log_builtins.h" #include "mysql/components/services/psi_stage_bits.h" #include "mysql/plugin.h" #include "mysql/psi/mysql_cond.h" #include "mysql/psi/mysql_file.h" #include "mysql/psi/mysql_mutex.h" #include "mysql/thread_type.h" #include "mysqld_error.h" #include "sql/binlog.h" #include "sql/binlog_reader.h" #include "sql/current_thd.h" #include "sql/debug_sync.h" #include "sql/log.h" #include "sql/mdl.h" #include "sql/mysqld.h" // key_mutex_slave_parallel_worker #include "sql/psi_memory_key.h" #include "sql/rpl_info_handler.h" #include "sql/rpl_msr.h" // For channel_map #include "sql/rpl_reporting.h" #include "sql/rpl_slave_commit_order_manager.h" // Commit_order_manager #include "sql/sql_error.h" #include "sql/sql_lex.h" #include "sql/table.h" #include "sql/transaction_info.h" #include "thr_mutex.h" #ifndef DBUG_OFF ulong w_rr = 0; uint mts_debug_concurrent_access = 0; #endif #define HASH_DYNAMIC_INIT 4 using std::max; using std::min; /** This function is called by both coordinator and workers. Upon receiving the STOP command, the workers will identify a maximum group index already executed (or under execution). All groups whose index are below or equal to the maximum group index will be applied by the workers before stopping. The workers with groups above the maximum group index will exit without applying these groups by setting their running status to "STOP_ACCEPTED". @param worker a pointer to the waiting Worker struct @param job_item a pointer to struct carrying a reference to an event @return true if STOP command gets accepted otherwise false is returned. */ bool handle_slave_worker_stop(Slave_worker *worker, Slave_job_item *job_item) { ulonglong group_index = 0; Relay_log_info *rli = worker->c_rli; mysql_mutex_lock(&rli->exit_count_lock); /* First, W calculates a group-"at-hands" index which is either the currently read ev group index, or the last executed group's one when the queue is empty. */ group_index = (job_item->data) ? rli->gaq->get_job_group(job_item->data->mts_group_idx)->total_seqno : worker->last_groups_assigned_index; /* The max updated index is being updated as long as exit_counter permits. That's stopped with the final W's increment of it. */ if (!worker->exit_incremented) { if (rli->exit_counter < rli->slave_parallel_workers) rli->max_updated_index = max(rli->max_updated_index, group_index); ++rli->exit_counter; worker->exit_incremented = true; DBUG_ASSERT(!is_mts_worker(current_thd)); } #ifndef DBUG_OFF else DBUG_ASSERT(is_mts_worker(current_thd)); #endif /* Now let's decide about the deferred exit to consider the empty queue and the counter value reached slave_parallel_workers. */ if (!job_item->data) { worker->running_status = Slave_worker::STOP_ACCEPTED; mysql_cond_signal(&worker->jobs_cond); mysql_mutex_unlock(&rli->exit_count_lock); return (true); } else if (rli->exit_counter == rli->slave_parallel_workers) { // over steppers should exit with accepting STOP if (group_index > rli->max_updated_index) { worker->running_status = Slave_worker::STOP_ACCEPTED; mysql_cond_signal(&worker->jobs_cond); mysql_mutex_unlock(&rli->exit_count_lock); return (true); } } mysql_mutex_unlock(&rli->exit_count_lock); return (false); } /** This function is called by both coordinator and workers. Both coordinator and workers contribute to max_updated_index. @param worker a pointer to the waiting Worker struct @param job_item a pointer to struct carrying a reference to an event @return true if STOP command gets accepted otherwise false is returned. */ bool set_max_updated_index_on_stop(Slave_worker *worker, Slave_job_item *job_item) { head_queue(&worker->jobs, job_item); if (worker->running_status == Slave_worker::STOP) { if (handle_slave_worker_stop(worker, job_item)) return true; } return false; } /* Please every time you add a new field to the worker slave info, update what follows. For now, this is just used to get the number of fields. */ const char *info_slave_worker_fields[] = { "id", /* These positions identify what has been executed. Notice that they are redudant and only the group_master_log_name and group_master_log_pos are really necessary. However, the additional information is kept to ease debugging. */ "group_relay_log_name", "group_relay_log_pos", "group_master_log_name", "group_master_log_pos", /* These positions identify what a worker knew about the coordinator at the time a job was assigned. Notice that they are redudant and are kept to ease debugging. */ "checkpoint_relay_log_name", "checkpoint_relay_log_pos", "checkpoint_master_log_name", "checkpoint_master_log_pos", /* Identify the greatest job, i.e. group, processed by a worker. */ "checkpoint_seqno", /* Maximum number of jobs that can be assigned to a worker. This information is necessary to read the next entry. */ "checkpoint_group_size", /* Bitmap used to identify what jobs were processed by a worker. */ "checkpoint_group_bitmap", /* Channel on which this workers are acting */ "channel_name"}; /* Number of records in the mts partition hash below which entries with zero usage are tolerated so could be quickly recycled. */ const ulong mts_partition_hash_soft_max = 16; /* index value of some outstanding slots of info_slave_worker_fields */ enum { LINE_FOR_CHANNEL = 12, }; const uint info_slave_worker_table_pk_field_indexes[] = { LINE_FOR_CHANNEL, 0, }; Slave_worker::Slave_worker(Relay_log_info *rli, #ifdef HAVE_PSI_INTERFACE PSI_mutex_key *param_key_info_run_lock, PSI_mutex_key *param_key_info_data_lock, PSI_mutex_key *param_key_info_sleep_lock, PSI_mutex_key *param_key_info_thd_lock, PSI_mutex_key *param_key_info_data_cond, PSI_mutex_key *param_key_info_start_cond, PSI_mutex_key *param_key_info_stop_cond, PSI_mutex_key *param_key_info_sleep_cond, #endif uint param_id, const char *param_channel) : Relay_log_info(false, #ifdef HAVE_PSI_INTERFACE param_key_info_run_lock, param_key_info_data_lock, param_key_info_sleep_lock, param_key_info_thd_lock, param_key_info_data_cond, param_key_info_start_cond, param_key_info_stop_cond, param_key_info_sleep_cond, #endif param_id + 1, param_channel, true), c_rli(rli), curr_group_exec_parts(key_memory_db_worker_hash_entry), id(param_id), checkpoint_relay_log_pos(0), checkpoint_master_log_pos(0), worker_checkpoint_seqno(0), running_status(NOT_RUNNING), exit_incremented(false) { /* In the future, it would be great if we use only one identifier. So when factoring out this code, please, consider this. */ DBUG_ASSERT(internal_id == id + 1); checkpoint_relay_log_name[0] = 0; checkpoint_master_log_name[0] = 0; mysql_mutex_init(key_mutex_slave_parallel_worker, &jobs_lock, MY_MUTEX_INIT_FAST); mysql_cond_init(key_cond_slave_parallel_worker, &jobs_cond); mysql_cond_init(key_cond_mts_gaq, &logical_clock_cond); } Slave_worker::~Slave_worker() { end_info(); if (jobs.inited_queue) { DBUG_ASSERT(jobs.m_Q.size() == jobs.size); jobs.m_Q.clear(); } mysql_mutex_destroy(&jobs_lock); mysql_cond_destroy(&jobs_cond); mysql_cond_destroy(&logical_clock_cond); mysql_mutex_lock(&info_thd_lock); info_thd = nullptr; mysql_mutex_unlock(&info_thd_lock); if (set_rli_description_event(nullptr)) { #ifndef DBUG_OFF bool set_rli_description_event_failed = false; #endif DBUG_ASSERT(set_rli_description_event_failed); } } /** Method is executed by Coordinator at Worker startup time to initialize members parly with values supplied by Coordinator through rli. @param rli Coordinator's Relay_log_info pointer @param i identifier of the Worker @return 0 success non-zero failure */ int Slave_worker::init_worker(Relay_log_info *rli, ulong i) { DBUG_TRACE; DBUG_ASSERT(!rli->info_thd->is_error()); Slave_job_item empty = Slave_job_item(); c_rli = rli; set_commit_order_manager(c_rli->get_commit_order_manager()); if (rli_init_info(false) || DBUG_EVALUATE_IF("inject_init_worker_init_info_fault", true, false)) return 1; if (!rli->is_privilege_checks_user_null()) { this->set_privilege_checks_user( rli->get_privilege_checks_username().c_str(), rli->get_privilege_checks_hostname().c_str()); } id = i; curr_group_exec_parts.clear(); relay_log_change_notified = false; // the 1st group to contain relaylog name checkpoint_notified = false; // the same as above master_log_change_notified = false; // W learns master log during 1st group exec fd_change_notified = false; // W is to learn master FD version same as above server_version = version_product(rli->slave_version_split); bitmap_shifted = 0; workers = c_rli->workers; // shallow copying is sufficient wq_empty_waits = wq_size_waits_cnt = groups_done = events_done = curr_jobs = 0; usage_partition = 0; end_group_sets_max_dbs = false; gaq_index = last_group_done_index = c_rli->gaq->size; // out of range last_groups_assigned_index = 0; DBUG_ASSERT(!jobs.inited_queue); jobs.avail = 0; jobs.len = 0; jobs.overfill = false; // todo: move into Slave_jobs_queue constructor jobs.waited_overfill = 0; jobs.entry = jobs.size = c_rli->mts_slave_worker_queue_len_max; jobs.inited_queue = true; curr_group_seen_gtid = false; #ifndef DBUG_OFF curr_group_seen_sequence_number = false; #endif jobs.m_Q.resize(jobs.size, empty); DBUG_ASSERT(jobs.m_Q.size() == jobs.size); wq_overrun_cnt = excess_cnt = 0; underrun_level = (ulong)((rli->mts_worker_underrun_level * jobs.size) / 100.0); // overrun level is symmetric to underrun (as underrun to the full queue) overrun_level = jobs.size - underrun_level; /* create mts submode for each of the the workers. */ current_mts_submode = (rli->channel_mts_submode == MTS_PARALLEL_TYPE_DB_NAME) ? (Mts_submode *)new Mts_submode_database() : (Mts_submode *)new Mts_submode_logical_clock(); // workers and coordinator must be of the same type DBUG_ASSERT(rli->current_mts_submode->get_type() == current_mts_submode->get_type()); m_order_commit_deadlock = false; return 0; } /** A part of Slave worker iitializer that provides a minimum context for MTS recovery. @param is_gaps_collecting_phase clarifies what state the caller executes this method from. When it's @c true that is @c mts_recovery_groups() and Worker should restore the last session time info which is processed to collect gaps that is not executed transactions (groups). Such recovery Slave_worker intance is destroyed at the end of @c mts_recovery_groups(). Whet it's @c false Slave_worker is initialized for the run time nad should not read the last session time stale info. Its info will be ultimately reset once all gaps are executed to finish off recovery. @return 0 on success, non-zero for a failure */ int Slave_worker::rli_init_info(bool is_gaps_collecting_phase) { enum_return_check return_check = ERROR_CHECKING_REPOSITORY; DBUG_TRACE; if (inited) return 0; /* Worker bitmap size depends on recovery mode. If it is gaps collecting the bitmaps must be capable to accept up to MTS_MAX_BITS_IN_GROUP of bits. */ size_t num_bits = is_gaps_collecting_phase ? MTS_MAX_BITS_IN_GROUP : c_rli->checkpoint_group; /* This checks if the repository was created before and thus there will be values to be read. Please, do not move this call after the handler->init_info(). */ return_check = check_info(); if (return_check == ERROR_CHECKING_REPOSITORY || (return_check == REPOSITORY_DOES_NOT_EXIST && is_gaps_collecting_phase)) goto err; if (handler->init_info()) goto err; bitmap_init(&group_executed, nullptr, num_bits, false); bitmap_init(&group_shifted, nullptr, num_bits, false); if (is_gaps_collecting_phase && (DBUG_EVALUATE_IF("mts_slave_worker_init_at_gaps_fails", true, false) || read_info(handler))) { bitmap_free(&group_executed); bitmap_free(&group_shifted); goto err; } inited = 1; return 0; err: // todo: handler->end_info(uidx, nidx); inited = 0; LogErr(ERROR_LEVEL, ER_RPL_ERROR_READING_SLAVE_WORKER_CONFIGURATION); return 1; } void Slave_worker::end_info() { DBUG_TRACE; if (!inited) return; if (handler) handler->end_info(); if (inited) { bitmap_free(&group_executed); bitmap_free(&group_shifted); } inited = 0; } int Slave_worker::flush_info(const bool force) { DBUG_TRACE; if (!inited) return 0; /* We update the sync_period at this point because only here we now that we are handling a Slave_worker. This needs to be update every time we call flush because the option may be dinamically set. */ handler->set_sync_period(sync_relayloginfo_period); if (write_info(handler)) goto err; if (handler->flush_info(force)) goto err; return 0; err: LogErr(ERROR_LEVEL, ER_RPL_ERROR_WRITING_SLAVE_WORKER_CONFIGURATION); return 1; } bool Slave_worker::read_info(Rpl_info_handler *from) { DBUG_TRACE; ulong temp_group_relay_log_pos = 0; ulong temp_group_master_log_pos = 0; ulong temp_checkpoint_relay_log_pos = 0; ulong temp_checkpoint_master_log_pos = 0; ulong temp_checkpoint_seqno = 0; ulong nbytes = 0; uchar *buffer = (uchar *)group_executed.bitmap; int temp_internal_id = 0; if (from->prepare_info_for_read()) return true; if (!!from->get_info(&temp_internal_id, 0) || !!from->get_info(group_relay_log_name, sizeof(group_relay_log_name), "") || !!from->get_info(&temp_group_relay_log_pos, 0UL) || !!from->get_info(group_master_log_name, sizeof(group_master_log_name), "") || !!from->get_info(&temp_group_master_log_pos, 0UL) || !!from->get_info(checkpoint_relay_log_name, sizeof(checkpoint_relay_log_name), "") || !!from->get_info(&temp_checkpoint_relay_log_pos, 0UL) || !!from->get_info(checkpoint_master_log_name, sizeof(checkpoint_master_log_name), "") || !!from->get_info(&temp_checkpoint_master_log_pos, 0UL) || !!from->get_info(&temp_checkpoint_seqno, 0UL) || !!from->get_info(&nbytes, 0UL) || !!from->get_info(buffer, (size_t)nbytes, (uchar *)0) || /* default is empty string */ !!from->get_info(channel, sizeof(channel), "")) return true; DBUG_ASSERT(nbytes <= no_bytes_in_map(&group_executed)); internal_id = (uint)temp_internal_id; group_relay_log_pos = temp_group_relay_log_pos; group_master_log_pos = temp_group_master_log_pos; checkpoint_relay_log_pos = temp_checkpoint_relay_log_pos; checkpoint_master_log_pos = temp_checkpoint_master_log_pos; worker_checkpoint_seqno = temp_checkpoint_seqno; return false; } /* This function is used to make a copy of the worker object before we destroy it while STOP SLAVE. This new object is then used to report the worker status until next START SLAVE following which the new worker objetcs will be used. */ void Slave_worker::copy_values_for_PFS(ulong worker_id, en_running_state thd_running_status, THD *worker_thd, const Error &last_error, Gtid_monitoring_info *monitoring_info) { id = worker_id; running_status = thd_running_status; info_thd = worker_thd; m_last_error = last_error; monitoring_info->copy_info_to(get_gtid_monitoring_info()); } bool Slave_worker::set_info_search_keys(Rpl_info_handler *to) { DBUG_TRACE; /* primary keys are Id and channel_name */ if (to->set_info(0, (int)internal_id) || to->set_info(LINE_FOR_CHANNEL, channel)) return true; return false; } bool Slave_worker::write_info(Rpl_info_handler *to) { DBUG_TRACE; ulong nbytes = (ulong)no_bytes_in_map(&group_executed); uchar *buffer = (uchar *)group_executed.bitmap; DBUG_ASSERT(nbytes <= (c_rli->checkpoint_group + 7) / 8); if (to->prepare_info_for_write() || to->set_info((int)internal_id) || to->set_info(group_relay_log_name) || to->set_info((ulong)group_relay_log_pos) || to->set_info(group_master_log_name) || to->set_info((ulong)group_master_log_pos) || to->set_info(checkpoint_relay_log_name) || to->set_info((ulong)checkpoint_relay_log_pos) || to->set_info(checkpoint_master_log_name) || to->set_info((ulong)checkpoint_master_log_pos) || to->set_info(worker_checkpoint_seqno) || to->set_info(nbytes) || to->set_info(buffer, (size_t)nbytes) || to->set_info(channel)) return true; return false; } /** Clean up a part of Worker info table that is regarded in in gaps collecting at recovery. This worker won't contribute to recovery bitmap at future slave restart (see @c mts_recovery_groups). @return false as success true as failure */ bool Slave_worker::reset_recovery_info() { DBUG_TRACE; set_group_master_log_name(""); set_group_master_log_pos(0); return flush_info(true); } size_t Slave_worker::get_number_worker_fields() { return sizeof(info_slave_worker_fields) / sizeof(info_slave_worker_fields[0]); } void Slave_worker::set_nullable_fields(MY_BITMAP *nullable_fields) { bitmap_init(nullable_fields, nullptr, Slave_worker::get_number_worker_fields(), false); bitmap_clear_all(nullable_fields); } const char *Slave_worker::get_master_log_name() { Slave_job_group *ptr_g = c_rli->gaq->get_job_group(gaq_index); return (ptr_g->checkpoint_log_name != nullptr) ? ptr_g->checkpoint_log_name : checkpoint_master_log_name; } bool Slave_worker::commit_positions(Log_event *ev, Slave_job_group *ptr_g, bool force) { DBUG_TRACE; /* Initial value of checkpoint_master_log_name is learned from group_master_log_name. The latter can be passed to Worker at rare event of master binlog rotation. This initialization is needed to provide to Worker info on physical coordiates during execution of the very first group after a rotation. */ if (ptr_g->group_master_log_name != nullptr) { strmake(group_master_log_name, ptr_g->group_master_log_name, sizeof(group_master_log_name) - 1); my_free(ptr_g->group_master_log_name); ptr_g->group_master_log_name = nullptr; strmake(checkpoint_master_log_name, group_master_log_name, sizeof(checkpoint_master_log_name) - 1); } if (ptr_g->checkpoint_log_name != nullptr) { strmake(checkpoint_relay_log_name, ptr_g->checkpoint_relay_log_name, sizeof(checkpoint_relay_log_name) - 1); checkpoint_relay_log_pos = ptr_g->checkpoint_relay_log_pos; strmake(checkpoint_master_log_name, ptr_g->checkpoint_log_name, sizeof(checkpoint_master_log_name) - 1); checkpoint_master_log_pos = ptr_g->checkpoint_log_pos; my_free(ptr_g->checkpoint_log_name); ptr_g->checkpoint_log_name = nullptr; my_free(ptr_g->checkpoint_relay_log_name); ptr_g->checkpoint_relay_log_name = nullptr; bitmap_copy(&group_shifted, &group_executed); bitmap_clear_all(&group_executed); for (uint pos = ptr_g->shifted; pos < c_rli->checkpoint_group; pos++) { if (bitmap_is_set(&group_shifted, pos)) bitmap_set_bit(&group_executed, pos - ptr_g->shifted); } } /* Extracts an updated relay-log name to store in Worker's rli. */ if (ptr_g->group_relay_log_name) { DBUG_ASSERT(strlen(ptr_g->group_relay_log_name) + 1 <= sizeof(group_relay_log_name)); strmake(group_relay_log_name, ptr_g->group_relay_log_name, sizeof(group_relay_log_name) - 1); } DBUG_ASSERT(ptr_g->checkpoint_seqno <= (c_rli->checkpoint_group - 1)); bitmap_set_bit(&group_executed, ptr_g->checkpoint_seqno); worker_checkpoint_seqno = ptr_g->checkpoint_seqno; group_relay_log_pos = ev->future_event_relay_log_pos; group_master_log_pos = ev->common_header->log_pos; /* Directly accessing c_rli->get_group_master_log_name() does not represent a concurrency issue because the current code places a synchronization point when master rotates. */ strmake(group_master_log_name, c_rli->get_group_master_log_name(), sizeof(group_master_log_name) - 1); DBUG_PRINT("mts", ("Committing worker-id %lu group master log pos %llu " "group master log name %s checkpoint sequence number %lu.", id, group_master_log_pos, group_master_log_name, worker_checkpoint_seqno)); DBUG_EXECUTE_IF("mts_debug_concurrent_access", { mts_debug_concurrent_access++; };); return flush_info(force); } void Slave_worker::rollback_positions(Slave_job_group *ptr_g) { if (!is_transactional()) { bitmap_clear_bit(&group_executed, ptr_g->checkpoint_seqno); flush_info(false); } } static void free_entry(db_worker_hash_entry *entry) { THD *c_thd = current_thd; DBUG_TRACE; DBUG_PRINT("info", ("free_entry %s, %zu", entry->db, strlen(entry->db))); DBUG_ASSERT(c_thd->system_thread == SYSTEM_THREAD_SLAVE_SQL); /* Although assert is correct valgrind senses entry->worker can be freed. DBUG_ASSERT(entry->usage == 0 || !entry->worker || // last entry owner could have errored out entry->worker->running_status != Slave_worker::RUNNING); */ mts_move_temp_tables_to_thd(c_thd, entry->temporary_tables); entry->temporary_tables = nullptr; my_free(const_cast(entry->db)); my_free(entry); } bool init_hash_workers(Relay_log_info *rli) { DBUG_TRACE; rli->inited_hash_workers = true; mysql_mutex_init(key_mutex_slave_worker_hash, &rli->slave_worker_hash_lock, MY_MUTEX_INIT_FAST); mysql_cond_init(key_cond_slave_worker_hash, &rli->slave_worker_hash_cond); return false; } void destroy_hash_workers(Relay_log_info *rli) { DBUG_TRACE; if (rli->inited_hash_workers) { rli->mapping_db_to_worker.clear(); mysql_mutex_destroy(&rli->slave_worker_hash_lock); mysql_cond_destroy(&rli->slave_worker_hash_cond); rli->inited_hash_workers = false; } } /** Relocating temporary table reference into @c entry's table list head. Sources can be the coordinator's and the Worker's thd->temporary_tables. @param table TABLE instance pointer @param thd THD instance pointer of the source of relocation @param entry db_worker_hash_entry instance pointer @note thd->temporary_tables can become NULL @return the pointer to a table following the unlinked */ TABLE *mts_move_temp_table_to_entry(TABLE *table, THD *thd, db_worker_hash_entry *entry) { TABLE *ret = table->next; if (table->prev) { table->prev->next = table->next; if (table->prev->next) table->next->prev = table->prev; } else { /* removing the first item from the list */ DBUG_ASSERT(table == thd->temporary_tables); thd->temporary_tables = table->next; if (thd->temporary_tables) table->next->prev = 0; } table->next = entry->temporary_tables; table->prev = 0; if (table->next) table->next->prev = table; entry->temporary_tables = table; return ret; } /** Relocation of the list of temporary tables to thd->temporary_tables. @param thd THD instance pointer of the destination @param temporary_tables the source temporary_tables list @note destroying references to the source list, if necessary, is left to the caller. @return the post-merge value of thd->temporary_tables. */ TABLE *mts_move_temp_tables_to_thd(THD *thd, TABLE *temporary_tables) { DBUG_TRACE; TABLE *table = temporary_tables; if (!table) return nullptr; // accept only if this is the start of the list. DBUG_ASSERT(!table->prev); // walk along the source list and associate the tables with thd do { table->in_use = thd; } while (table->next && (table = table->next)); // link the former list against the tail of the source list if (thd->temporary_tables) thd->temporary_tables->prev = table; table->next = thd->temporary_tables; thd->temporary_tables = temporary_tables; return thd->temporary_tables; } /** Relocating references of temporary tables of a database of the entry argument from THD into the entry. @param thd THD pointer of the source temporary_tables list @param entry a pointer to db_worker_hash_entry record containing database descriptor and temporary_tables list. */ static void move_temp_tables_to_entry(THD *thd, db_worker_hash_entry *entry) { for (TABLE *table = thd->temporary_tables; table;) { if (strcmp(table->s->db.str, entry->db) == 0) { // table pointer is shifted inside the function table = mts_move_temp_table_to_entry(table, thd, entry); } else { table = table->next; } } } /** The function produces a reference to the struct of a Worker that has been or will be engaged to process the @c dbname -keyed partition (D). It checks a local to Coordinator CGAP list first and returns @c last_assigned_worker when found (todo: assert). Otherwise, the partition is appended to the current group list: CGAP .= D here .= is concatenate operation, and a possible D's Worker id is searched in Assigned Partition Hash (APH) that collects tuples (P, W_id, U, mutex, cond). In case not found, W_d := W_c unless W_c is NULL. When W_c is NULL it is assigned to a least occupied as defined by @c get_least_occupied_worker(). W_d := W_c := W_{least_occupied} APH .= a new (D, W_d, 1) In a case APH contains W_d == W_c, (assert U >= 1) update APH set U++ where APH.P = D The case APH contains a W_d != W_c != NULL assigned to D-partition represents the hashing conflict and is handled as the following: a. marks the record of APH with a flag requesting to signal in the cond var when `U' the usage counter drops to zero by the other Worker; b. waits for the other Worker to finish tasks on that partition and gets the signal; c. updates the APH record to point to the first Worker (naturally, U := 1), scheduled the event, and goes back into the parallel mode @param dbname pointer to c-string containing database name It can be empty string to indicate specific locking to faciliate sequential applying. @param rli pointer to Coordinators relay-log-info instance @param ptr_entry reference to a pointer to the resulted entry in the Assigne Partition Hash where the entry's pointer is stored at return. @param need_temp_tables if false migration of temporary tables not needed @param last_worker caller opts for this Worker, it must be rli->last_assigned_worker if one is determined. @note modifies CGAP, APH and unlinks @c dbname -keyd temporary tables from C's thd->temporary_tables to move them into the entry record. @return the pointer to a Worker struct */ Slave_worker *map_db_to_worker(const char *dbname, Relay_log_info *rli, db_worker_hash_entry **ptr_entry, bool need_temp_tables, Slave_worker *last_worker) { Slave_worker_array *workers = &rli->workers; THD *thd = rli->info_thd; DBUG_TRACE; DBUG_ASSERT(!rli->last_assigned_worker || rli->last_assigned_worker == last_worker); DBUG_ASSERT(is_mts_db_partitioned(rli)); if (!rli->inited_hash_workers) return nullptr; db_worker_hash_entry *entry = nullptr; size_t dblength = strlen(dbname); // Search in CGAP for (db_worker_hash_entry **it = rli->curr_group_assigned_parts.begin(); it != rli->curr_group_assigned_parts.end(); ++it) { entry = *it; if ((uchar)entry->db_len != dblength) continue; else if (strncmp(entry->db, const_cast(dbname), dblength) == 0) { *ptr_entry = entry; return last_worker; } } DBUG_PRINT("info", ("Searching for %s, %zu", dbname, dblength)); mysql_mutex_lock(&rli->slave_worker_hash_lock); std::string key(dbname, dblength); entry = find_or_nullptr(rli->mapping_db_to_worker, key); if (!entry) { /* The database name was not found which means that a worker never processed events from that database. In such case, we need to map the database to a worker my inserting an entry into the hash map. */ bool ret; char *db = nullptr; mysql_mutex_unlock(&rli->slave_worker_hash_lock); DBUG_PRINT("info", ("Inserting %s, %zu", dbname, dblength)); /* Allocate an entry to be inserted and if the operation fails an error is returned. */ if (!(db = (char *)my_malloc(key_memory_db_worker_hash_entry, dblength + 1, MYF(0)))) goto err; if (!(entry = (db_worker_hash_entry *)my_malloc( key_memory_db_worker_hash_entry, sizeof(db_worker_hash_entry), MYF(0)))) { my_free(db); goto err; } my_stpcpy(db, dbname); entry->db = db; entry->db_len = strlen(db); entry->usage = 1; entry->temporary_tables = nullptr; /* Unless \exists the last assigned Worker, get a free worker based on a policy described in the function get_least_occupied_worker(). */ mysql_mutex_lock(&rli->slave_worker_hash_lock); entry->worker = (!last_worker) ? get_least_occupied_worker(rli, workers, nullptr) : last_worker; entry->worker->usage_partition++; if (rli->mapping_db_to_worker.size() > mts_partition_hash_soft_max) { /* remove zero-usage (todo: rare or long ago scheduled) records. Free the element if the usage of the hash entry is 0 or not. */ for (auto it = rli->mapping_db_to_worker.begin(); it != rli->mapping_db_to_worker.end();) { DBUG_ASSERT(!entry->temporary_tables || !entry->temporary_tables->prev); DBUG_ASSERT(!thd->temporary_tables || !thd->temporary_tables->prev); db_worker_hash_entry *entry = it->second.get(); if (entry->usage == 0) { mts_move_temp_tables_to_thd(thd, entry->temporary_tables); entry->temporary_tables = nullptr; it = rli->mapping_db_to_worker.erase(it); } else ++it; } } ret = !rli->mapping_db_to_worker .emplace(entry->db, unique_ptr_with_deleter( entry, free_entry)) .second; if (ret) { my_free(db); entry = nullptr; goto err; } DBUG_PRINT("info", ("Inserted %s, %zu", entry->db, strlen(entry->db))); } else { /* There is a record. Either */ if (entry->usage == 0) { entry->worker = (!last_worker) ? get_least_occupied_worker(rli, workers, nullptr) : last_worker; entry->worker->usage_partition++; entry->usage++; } else if (entry->worker == last_worker || !last_worker) { DBUG_ASSERT(entry->worker); entry->usage++; } else { // The case APH contains a W_d != W_c != NULL assigned to // D-partition represents // the hashing conflict and is handled as the following: PSI_stage_info old_stage; DBUG_ASSERT(last_worker != nullptr && rli->curr_group_assigned_parts.size() > 0); // future assignenment and marking at the same time entry->worker = last_worker; // loop while a user thread is stopping Coordinator gracefully do { thd->ENTER_COND( &rli->slave_worker_hash_cond, &rli->slave_worker_hash_lock, &stage_slave_waiting_worker_to_release_partition, &old_stage); mysql_cond_wait(&rli->slave_worker_hash_cond, &rli->slave_worker_hash_lock); } while (entry->usage != 0 && !thd->killed); mysql_mutex_unlock(&rli->slave_worker_hash_lock); thd->EXIT_COND(&old_stage); if (thd->killed) { entry = nullptr; goto err; } mysql_mutex_lock(&rli->slave_worker_hash_lock); entry->usage = 1; entry->worker->usage_partition++; } } /* relocation belonging to db temporary tables from C to W via entry */ if (entry->usage == 1 && need_temp_tables) { if (!entry->temporary_tables) { if (entry->db_len != 0) { move_temp_tables_to_entry(thd, entry); } else { entry->temporary_tables = thd->temporary_tables; thd->temporary_tables = nullptr; } } #ifndef DBUG_OFF else { // all entries must have been emptied from temps by the caller for (TABLE *table = thd->temporary_tables; table; table = table->next) { DBUG_ASSERT(0 != strcmp(table->s->db.str, entry->db)); } } #endif } mysql_mutex_unlock(&rli->slave_worker_hash_lock); DBUG_ASSERT(entry); err: if (entry) { DBUG_PRINT("info", ("Updating %s with worker %lu", entry->db, entry->worker->id)); rli->curr_group_assigned_parts.push_back(entry); *ptr_entry = entry; } return entry ? entry->worker : nullptr; } /** Get the least occupied worker. @param rli pointer to Relay_log_info of Coordinator @param ws dynarray of pointers to Slave_worker @param ev event for which we are searching for a worker @return a pointer to chosen Slave_worker instance */ Slave_worker *get_least_occupied_worker(Relay_log_info *rli, Slave_worker_array *ws, Log_event *ev) { return rli->current_mts_submode->get_least_occupied_worker(rli, ws, ev); } /** Deallocation routine to cancel out few effects of @c map_db_to_worker(). Involved into processing of the group APH tuples are updated. @c last_group_done_index member is set to the GAQ index of the current group. CGEP the Worker partition cache is cleaned up. @param ev a pointer to Log_event @param error error code after processing the event by caller. */ void Slave_worker::slave_worker_ends_group(Log_event *ev, int error) { DBUG_TRACE; Slave_job_group *ptr_g = nullptr; if (!error) { ptr_g = c_rli->gaq->get_job_group(gaq_index); DBUG_ASSERT(gaq_index == ev->mts_group_idx); /* It guarantees that the worker is removed from order commit queue when its transaction doesn't binlog anything. It will break innodb group commit, but it should rarely happen. */ if (get_commit_order_manager()) get_commit_order_manager()->report_commit(this); // first ever group must have relay log name DBUG_ASSERT(last_group_done_index != c_rli->gaq->size || ptr_g->group_relay_log_name != nullptr); DBUG_ASSERT(ptr_g->worker_id == id); /* DDL that has not yet updated the slave info repository does it now. */ if (ev->get_type_code() != binary_log::XID_EVENT && !is_committed_ddl(ev)) { commit_positions(ev, ptr_g, true); DBUG_EXECUTE_IF( "crash_after_commit_and_update_pos", sql_print_information("Crashing crash_after_commit_and_update_pos."); flush_info(true); DBUG_SUICIDE();); } ptr_g->group_master_log_pos = group_master_log_pos; ptr_g->group_relay_log_pos = group_relay_log_pos; ptr_g->done.store(1); last_group_done_index = gaq_index; last_groups_assigned_index = ptr_g->total_seqno; reset_gaq_index(); groups_done++; } else { if (running_status != STOP_ACCEPTED) { // tagging as exiting so Coordinator won't be able synchronize with it mysql_mutex_lock(&jobs_lock); running_status = ERROR_LEAVING; mysql_mutex_unlock(&jobs_lock); /* Fatal error happens, it notifies the following transaction to rollback */ if (get_commit_order_manager()) get_commit_order_manager()->report_rollback(this); // Killing Coordinator to indicate eventual consistency error mysql_mutex_lock(&c_rli->info_thd->LOCK_thd_data); c_rli->info_thd->awake(THD::KILL_QUERY); mysql_mutex_unlock(&c_rli->info_thd->LOCK_thd_data); } } /* Cleanup relating to the last executed group regardless of error. */ if (current_mts_submode->get_type() == MTS_PARALLEL_TYPE_DB_NAME) { for (size_t i = 0; i < curr_group_exec_parts.size(); i++) { db_worker_hash_entry *entry = curr_group_exec_parts[i]; mysql_mutex_lock(&c_rli->slave_worker_hash_lock); DBUG_ASSERT(entry); entry->usage--; DBUG_ASSERT(entry->usage >= 0); if (entry->usage == 0) { usage_partition--; /* The detached entry's temp table list, possibly updated, remains with the entry at least until time Coordinator will deallocate it from the hash, that is either due to stop or extra size of the hash. */ DBUG_ASSERT(usage_partition >= 0); DBUG_ASSERT(this->info_thd->temporary_tables == 0); DBUG_ASSERT(!entry->temporary_tables || !entry->temporary_tables->prev); if (entry->worker != this) // Coordinator is waiting { DBUG_PRINT("info", ("Notifying entry %p release by worker %lu", entry, this->id)); mysql_cond_signal(&c_rli->slave_worker_hash_cond); } } else DBUG_ASSERT(usage_partition != 0); mysql_mutex_unlock(&c_rli->slave_worker_hash_lock); } curr_group_exec_parts.clear(); curr_group_exec_parts.shrink_to_fit(); if (error) { // Awakening Coordinator that could be waiting for entry release mysql_mutex_lock(&c_rli->slave_worker_hash_lock); mysql_cond_signal(&c_rli->slave_worker_hash_cond); mysql_mutex_unlock(&c_rli->slave_worker_hash_lock); } } else // not DB-type scheduler { DBUG_ASSERT(current_mts_submode->get_type() == MTS_PARALLEL_TYPE_LOGICAL_CLOCK); /* Check if there're any waiter. If there're try incrementing lwm and signal to those who've got sasfied with the waiting condition. In a "good" "likely" execution branch the waiter set is expected to be empty. LWM is advanced by Coordinator asynchronously. Also lwm is advanced by a dependent Worker when it inserts its waiting request into the waiting list. */ Mts_submode_logical_clock *mts_submode = static_cast(c_rli->current_mts_submode); int64 min_child_waited_logical_ts = mts_submode->min_waited_timestamp.load(); DBUG_EXECUTE_IF("slave_worker_ends_group_before_signal_lwm", { const char act[] = "now WAIT_FOR worker_continue"; DBUG_ASSERT(!debug_sync_set_action(current_thd, STRING_WITH_LEN(act))); }); if (unlikely(error)) { mysql_mutex_lock(&c_rli->mts_gaq_LOCK); mts_submode->is_error = true; if (mts_submode->min_waited_timestamp != SEQ_UNINIT) mysql_cond_signal(&c_rli->logical_clock_cond); mysql_mutex_unlock(&c_rli->mts_gaq_LOCK); } else if (min_child_waited_logical_ts != SEQ_UNINIT) { mysql_mutex_lock(&c_rli->mts_gaq_LOCK); /* min_child_waited_logical_ts may include an old value, so we need to check it again after getting the lock. */ if (mts_submode->min_waited_timestamp != SEQ_UNINIT) { longlong curr_lwm = mts_submode->get_lwm_timestamp(c_rli, true); if (mts_submode->clock_leq(mts_submode->min_waited_timestamp, curr_lwm)) { /* There's a transaction that depends on the current. */ mysql_cond_signal(&c_rli->logical_clock_cond); } } mysql_mutex_unlock(&c_rli->mts_gaq_LOCK); } #ifndef DBUG_OFF curr_group_seen_sequence_number = false; #endif } curr_group_seen_gtid = false; } /** two index comparision to determine which of the two is ordered first. @note The caller makes sure the args are within the valid range, incl cases the queue is empty or full. @return true if the first arg identifies a queue entity ordered after one defined by the 2nd arg, false otherwise. */ template bool circular_buffer_queue::gt(ulong i, ulong k) { DBUG_ASSERT(i < size && k < size); DBUG_ASSERT(avail != entry); if (i >= entry) if (k >= entry) return i > k; else return false; else if (k >= entry) return true; else return i > k; } Slave_committed_queue::Slave_committed_queue(ulong max, uint n) : circular_buffer_queue(max), inited(false), last_done(key_memory_Slave_job_group_group_relay_log_name) { if (max >= (ulong)-1 || !inited_queue) return; else inited = true; last_done.resize(n); lwm.group_relay_log_name = (char *)my_malloc( key_memory_Slave_job_group_group_relay_log_name, FN_REFLEN + 1, MYF(0)); lwm.group_relay_log_name[0] = 0; lwm.sequence_number = SEQ_UNINIT; } #ifndef DBUG_OFF bool Slave_committed_queue::count_done(Relay_log_info *rli) { ulong i, k, cnt = 0; for (i = entry, k = 0; k < len; i = (i + 1) % size, k++) { Slave_job_group *ptr_g; ptr_g = &m_Q[i]; if (ptr_g->worker_id != MTS_WORKER_UNDEF && ptr_g->done) cnt++; } DBUG_ASSERT(cnt <= size); DBUG_PRINT("mts", ("Checking if it can simulate a crash:" " mts_checkpoint_group %u counter %lu parallel slaves %lu\n", opt_mts_checkpoint_group, cnt, rli->slave_parallel_workers)); return (cnt == (rli->slave_parallel_workers * opt_mts_checkpoint_group)); } #endif /** The queue is processed from the head item by item to purge items representing committed groups. Progress in GAQ is assessed through comparision of GAQ index value with Worker's @c last_group_done_index. Purging breaks at a first discovered gap, that is an item that the assinged item->w_id'th Worker has not yet completed. The caller is supposed to be the checkpoint handler. A copy of the last discarded item containing the refreshed value of the committed low-water-mark is stored into @c lwm container member for further caller's processing. @c last_done is updated with the latest total_seqno for each Worker that was met during GAQ parse. @note dyn-allocated members of Slave_job_group such as group_relay_log_name as freed here. @return number of discarded items */ ulong Slave_committed_queue::move_queue_head(Slave_worker_array *ws) { DBUG_TRACE; ulong i, cnt = 0; for (i = entry; i != avail && !empty(); cnt++, i = (i + 1) % size) { Slave_worker *w_i; Slave_job_group *ptr_g; char grl_name[FN_REFLEN]; #ifndef DBUG_OFF if (DBUG_EVALUATE_IF("check_slave_debug_group", 1, 0) && cnt == opt_mts_checkpoint_period) return cnt; #endif grl_name[0] = 0; ptr_g = &m_Q[i]; /* The current job has not been processed or it was not even assigned, this means there is a gap. */ if (ptr_g->worker_id == MTS_WORKER_UNDEF || ptr_g->done.load() == 0) break; /* gap at i'th */ /* Worker-id domain guard */ static_assert(MTS_WORKER_UNDEF > MTS_MAX_WORKERS, ""); w_i = ws->at(ptr_g->worker_id); /* Memorizes the latest valid group_relay_log_name. */ if (ptr_g->group_relay_log_name) { strcpy(grl_name, ptr_g->group_relay_log_name); my_free(ptr_g->group_relay_log_name); /* It is important to mark the field as freed. */ ptr_g->group_relay_log_name = nullptr; } /* Removes the job from the (G)lobal (A)ssigned (Q)ueue. */ Slave_job_group g = Slave_job_group(); #ifndef DBUG_OFF ulong ind = #endif de_queue(&g); /* Stores the memorized name into the result struct. Note that we take care of the pointer first and then copy the other elements by assigning the structures. */ if (grl_name[0] != 0) { strcpy(lwm.group_relay_log_name, grl_name); } g.group_relay_log_name = lwm.group_relay_log_name; lwm = g; DBUG_ASSERT(ind == i); DBUG_ASSERT(!ptr_g->group_relay_log_name); DBUG_ASSERT(ptr_g->total_seqno == lwm.total_seqno); #ifndef DBUG_OFF { ulonglong l = last_done[w_i->id]; /* There must be some progress otherwise we should have exit the loop earlier. */ DBUG_ASSERT(l < ptr_g->total_seqno); } #endif /* This is used to calculate the last time each worker has processed events. */ last_done[w_i->id] = ptr_g->total_seqno; } DBUG_ASSERT(cnt <= size); return cnt; } /** Finds low-water mark of committed jobs in GAQ. That is an index below which all jobs are marked as done. Notice the first available index is returned when the queue does not have any incomplete jobs. That includes cases of the empty and the full of complete jobs queue. A mutex protecting from concurrent LWM change by move_queue_head() (by Coordinator) should be taken by the caller. @param [out] arg_g a double pointer to Slave job descriptor item last marked with done-as-true boolean. @param start_index a GAQ index to start/resume searching. Caller is to make sure the index points into assigned (occupied) range of circular buffer of GAQ. @return GAQ index of the last consecutive done job, or the GAQ size when none is found. */ ulong Slave_committed_queue::find_lwm(Slave_job_group **arg_g, ulong start_index) { Slave_job_group *ptr_g = nullptr; ulong i, k, cnt; DBUG_ASSERT(start_index <= size); if (empty()) return size; /* Loop continuation condition relies on (TODO: assert it) the start_index being in the running range: start_index \in [entry, avail - 1]. It satisfies any queue size including 1. It does not satisfy the empty queue case which is bailed out earlier above. */ for (i = start_index, cnt = 0; cnt < len - (start_index + size - entry) % size; i = (i + 1) % size, cnt++) { ptr_g = &m_Q[i]; if (ptr_g->done.load() == 0) { if (cnt == 0) return size; // the first node of the queue is not done break; } } ptr_g = &m_Q[k = (i + size - 1) % size]; *arg_g = ptr_g; return k; } /** Method should be executed at slave system stop to cleanup dynamically allocated items that remained as unprocessed by Coordinator and Workers in their regular execution course. */ void Slave_committed_queue::free_dynamic_items() { ulong i, k; for (i = entry, k = 0; k < len; i = (i + 1) % size, k++) { Slave_job_group *ptr_g = &m_Q[i]; if (ptr_g->group_relay_log_name) { my_free(ptr_g->group_relay_log_name); } if (ptr_g->checkpoint_log_name) { my_free(ptr_g->checkpoint_log_name); } if (ptr_g->checkpoint_relay_log_name) { my_free(ptr_g->checkpoint_relay_log_name); } if (ptr_g->group_master_log_name) { my_free(ptr_g->group_master_log_name); } } DBUG_ASSERT((avail == size /* full */ || entry == size /* empty */) || i == avail /* all occupied are processed */); } void Slave_worker::do_report(loglevel level, int err_code, const char *msg, va_list args) const { char buff_coord[MAX_SLAVE_ERRMSG]; char buff_gtid[Gtid::MAX_TEXT_LENGTH + 1]; const char *log_name = const_cast(this)->get_master_log_name(); ulonglong log_pos = const_cast(this)->get_master_log_pos(); bool is_group_replication_applier_channel = channel_map.is_group_replication_channel_name(c_rli->get_channel(), true); const Gtid_specification *gtid_next = &info_thd->variables.gtid_next; THD *thd = info_thd; gtid_next->to_string(global_sid_map, buff_gtid, true); if (level == ERROR_LEVEL && (!has_temporary_error(thd, err_code) || thd->get_transaction()->cannot_safely_rollback( Transaction_ctx::SESSION))) { char coordinator_errmsg[MAX_SLAVE_ERRMSG]; if (is_group_replication_applier_channel) { snprintf(coordinator_errmsg, MAX_SLAVE_ERRMSG, "Coordinator stopped because there were error(s) in the " "worker(s). " "The most recent failure being: Worker %u failed executing " "transaction '%s'. See error log and/or " "performance_schema.replication_applier_status_by_worker " "table for " "more details about this failure or others, if any.", internal_id, buff_gtid); } else { snprintf(coordinator_errmsg, MAX_SLAVE_ERRMSG, "Coordinator stopped because there were error(s) in the " "worker(s). " "The most recent failure being: Worker %u failed executing " "transaction '%s' at master log %s, end_log_pos %llu. " "See error log and/or " "performance_schema.replication_applier_status_by_worker " "table for " "more details about this failure or others, if any.", internal_id, buff_gtid, log_name, log_pos); } /* We want to update the errors in coordinator as well as worker. The fill_coord_err_buf() function update the error number, message and timestamp fields. This function is different from va_report() as va_report() also logs the error message in the log apart from updating the error fields. So, the worker does the job of reporting the error in the log. We just make coordinator aware of the error. */ c_rli->fill_coord_err_buf(level, err_code, coordinator_errmsg); } if (is_group_replication_applier_channel) { snprintf(buff_coord, sizeof(buff_coord), "Worker %u failed executing transaction '%s'", internal_id, buff_gtid); } else { snprintf(buff_coord, sizeof(buff_coord), "Worker %u failed executing transaction '%s' at " "master log %s, end_log_pos %llu", internal_id, buff_gtid, log_name, log_pos); } /* Error reporting by the worker. The worker updates its error fields as well as reports the error in the log. */ this->va_report(level, err_code, buff_coord, msg, args); } #ifndef DBUG_OFF static bool may_have_timestamp(Log_event *ev) { bool res = false; switch (ev->get_type_code()) { case binary_log::QUERY_EVENT: res = true; break; case binary_log::GTID_LOG_EVENT: res = true; break; default: break; } return res; } static int64 get_last_committed(Log_event *ev) { int64 res = SEQ_UNINIT; switch (ev->get_type_code()) { case binary_log::GTID_LOG_EVENT: res = static_cast(ev)->last_committed; break; default: break; } return res; } static int64 get_sequence_number(Log_event *ev) { int64 res = SEQ_UNINIT; switch (ev->get_type_code()) { case binary_log::GTID_LOG_EVENT: res = static_cast(ev)->sequence_number; break; default: break; } return res; } #endif /** MTS worker main routine. The worker thread loops in waiting for an event, executing it and fixing statistics counters. @return 0 success -1 got killed or an error happened during applying */ int Slave_worker::slave_worker_exec_event(Log_event *ev) { Relay_log_info *rli = c_rli; THD *thd = info_thd; int ret = 0; DBUG_TRACE; thd->server_id = ev->server_id; thd->set_time(); thd->lex->set_current_select(0); if (!ev->common_header->when.tv_sec) ev->common_header->when.tv_sec = static_cast(my_time(0)); ev->thd = thd; // todo: assert because up to this point, ev->thd == 0 ev->worker = this; #ifndef DBUG_OFF if (!is_mts_db_partitioned(rli) && may_have_timestamp(ev) && !curr_group_seen_sequence_number) { curr_group_seen_sequence_number = true; longlong lwm_estimate = static_cast(rli->current_mts_submode) ->estimate_lwm_timestamp(); int64 last_committed = get_last_committed(ev); int64 sequence_number = get_sequence_number(ev); /* The commit timestamp waiting condition: lwm_estimate < last_committed <=> last_committed \not <= lwm_estimate must have been satisfied by Coordinator. The first scheduled transaction does not have to wait for anybody. */ DBUG_ASSERT( rli->gaq->entry == ev->mts_group_idx || Mts_submode_logical_clock::clock_leq(last_committed, lwm_estimate)); DBUG_ASSERT(lwm_estimate != SEQ_UNINIT || rli->gaq->entry == ev->mts_group_idx); /* The current transaction's timestamp can't be less that lwm. */ DBUG_ASSERT(sequence_number == SEQ_UNINIT || !Mts_submode_logical_clock::clock_leq( sequence_number, static_cast( rli->current_mts_submode) ->estimate_lwm_timestamp())); } #endif // Address partioning only in database mode if (!is_gtid_event(ev) && is_mts_db_partitioned(rli)) { if (ev->contains_partition_info(end_group_sets_max_dbs)) { uint num_dbs = ev->mts_number_dbs(); if (num_dbs == OVER_MAX_DBS_IN_EVENT_MTS) num_dbs = 1; DBUG_ASSERT(num_dbs > 0); for (uint k = 0; k < num_dbs; k++) { bool found = false; for (size_t i = 0; i < curr_group_exec_parts.size() && !found; i++) { found = curr_group_exec_parts[i] == ev->mts_assigned_partitions[k]; } if (!found) { /* notice, can't assert DBUG_ASSERT(ev->mts_assigned_partitions[k]->worker == worker); since entry could be marked as wanted by other worker. */ curr_group_exec_parts.push_back(ev->mts_assigned_partitions[k]); } } end_group_sets_max_dbs = false; } } set_future_event_relay_log_pos(ev->future_event_relay_log_pos); set_master_log_pos(static_cast(ev->common_header->log_pos)); set_gaq_index(ev->mts_group_idx); ret = ev->do_apply_event_worker(this); return ret; } /** Sleep for a given amount of seconds or until killed. @param seconds The number of seconds to sleep. @retval True if the thread has been killed, false otherwise. */ bool Slave_worker::worker_sleep(ulong seconds) { bool ret = false; struct timespec abstime; mysql_mutex_t *lock = &jobs_lock; mysql_cond_t *cond = &jobs_cond; /* Absolute system time at which the sleep time expires. */ set_timespec(&abstime, seconds); mysql_mutex_lock(lock); info_thd->ENTER_COND(cond, lock, nullptr, nullptr); while (!(ret = info_thd->killed || running_status != RUNNING)) { int error = mysql_cond_timedwait(cond, lock, &abstime); if (is_timeout(error)) break; } mysql_mutex_unlock(lock); info_thd->EXIT_COND(nullptr); return ret; } /** It is called after an error happens. It checks if that is an temporary error and if the situation is allow to retry the transaction. Then it will retry the transaction if it is allowed. Retry policy and logic is similar to single-threaded slave. @param[in] start_relay_number The extension number of the relay log which includes the first event of the transaction. @param[in] start_relay_pos The offset of the transaction's first event. @param[in] end_relay_number The extension number of the relay log which includes the last event it should retry. @param[in] end_relay_pos The offset of the last event it should retry. @return false if succeeds, otherwise returns true. */ bool Slave_worker::retry_transaction(uint start_relay_number, my_off_t start_relay_pos, uint end_relay_number, my_off_t end_relay_pos) { THD *thd = info_thd; bool silent = false; DBUG_TRACE; if (slave_trans_retries == 0) return true; do { /* Simulate a lock deadlock error */ uint error = 0; if (found_order_commit_deadlock()) { /* This transaction was allowed to be executed in parallel with other that happened earlier according to binary log order. It was asked to be rolled back by the other transaction as it was holding a lock that is needed by the other transaction to progress, according to binary log order this configure a deadlock. At this point, this transaction *should* have no non-temporary errors. Having a non-temporary error may be a sign of: a) Slave has diverged from the master; b) There is an issue in the logical clock allowing a transaction to be applied in parallel with its dependencies (the two transactions are trying to change the same record in parallel). For (a), a retry of this transaction will produce the same error. For (b), this transaction might succeed upon retry, allowing the slave to progress without manual intervention, but it is a sign of problems in LC generation at the master. So, we will make the worker to retry this transaction only if there is no error or the error is a temporary error. */ Diagnostics_area *da = thd->get_stmt_da(); if (!thd->get_stmt_da()->is_error() || has_temporary_error(thd, da->is_error() ? da->mysql_errno() : error, &silent)) { error = ER_LOCK_DEADLOCK; } #ifndef DBUG_OFF else { /* The non-debug binary will not retry this transactions, stopping the SQL thread because of the non-temporary error. But, as this situation is not supposed to happen as described in the comment above, we will fail an assert to ease the issue investigation when it happens. */ if (DBUG_EVALUATE_IF("rpl_fake_cod_deadlock", 0, 1)) DBUG_ASSERT(false); } #endif } if (!has_temporary_error(thd, error, &silent) || thd->get_transaction()->cannot_safely_rollback( Transaction_ctx::SESSION)) return true; if (trans_retries >= slave_trans_retries) { thd->fatal_error(); c_rli->report(ERROR_LEVEL, thd->get_stmt_da()->mysql_errno(), "worker thread retried transaction %lu time(s) " "in vain, giving up. Consider raising the value of " "the slave_transaction_retries variable.", trans_retries); return true; } if (!silent) { trans_retries++; if (current_thd->rli_slave->is_processing_trx()) { // if the error code is zero, we get the top of the error stack uint transient_error = (error == 0) ? thd->get_stmt_da()->mysql_errno() : error; current_thd->rli_slave->retried_processing( transient_error, ER_THD_NONCONST(thd, transient_error), trans_retries); #ifndef DBUG_OFF if (trans_retries == 2 || trans_retries == 6) DBUG_EXECUTE_IF("rpl_ps_tables_worker_retry", { char const act[] = "now SIGNAL signal.rpl_ps_tables_worker_retry_pause " "WAIT_FOR signal.rpl_ps_tables_worker_retry_continue"; DBUG_ASSERT(opt_debug_sync_timeout > 0); // we can't add the usual DBUG_ASSERT here because thd->is_error() // is true (and that's OK) debug_sync_set_action(thd, STRING_WITH_LEN(act)); }); #endif } } mysql_mutex_lock(&c_rli->data_lock); c_rli->retried_trans++; mysql_mutex_unlock(&c_rli->data_lock); cleanup_context(thd, 1); reset_order_commit_deadlock(); worker_sleep(min(trans_retries, MAX_SLAVE_RETRY_PAUSE)); } while (read_and_apply_events(start_relay_number, start_relay_pos, end_relay_number, end_relay_pos)); return false; } /** Read events from relay logs and apply them. @param[in] start_relay_number The extension number of the relay log which includes the first event of the transaction. @param[in] start_relay_pos The offset of the transaction's first event. @param[in] end_relay_number The extension number of the relay log which includes the last event it should retry. @param[in] end_relay_pos The offset of the last event it should retry. @return false if succeeds, otherwise returns true. */ bool Slave_worker::read_and_apply_events(uint start_relay_number, my_off_t start_relay_pos, uint end_relay_number, my_off_t end_relay_pos) { DBUG_TRACE; Relay_log_info *rli = c_rli; char file_name[FN_REFLEN + 1]; uint file_number = start_relay_number; bool error = true; bool arrive_end = false; Relaylog_file_reader relaylog_file_reader(opt_slave_sql_verify_checksum); relay_log_number_to_name(start_relay_number, file_name); while (!arrive_end) { Log_event *ev = nullptr; if (!relaylog_file_reader.is_open()) { DBUG_PRINT("info", ("Open relay log %s", file_name)); if (relaylog_file_reader.open(file_name, start_relay_pos)) { LogErr(ERROR_LEVEL, ER_RPL_FAILED_TO_OPEN_RELAY_LOG, file_name, relaylog_file_reader.get_error_str()); goto end; } } /* If it is the last event, then set arrive_end as true */ arrive_end = (relaylog_file_reader.position() == end_relay_pos && file_number == end_relay_number); ev = relaylog_file_reader.read_event_object(); if (ev != nullptr) { /* It is a event belongs to the transaction */ if (!ev->is_mts_sequential_exec()) { int ret = 0; ev->future_event_relay_log_pos = relaylog_file_reader.position(); ev->mts_group_idx = gaq_index; if (is_mts_db_partitioned(rli) && ev->contains_partition_info(true)) assign_partition_db(ev); ret = slave_worker_exec_event(ev); if (ev->worker != nullptr) { delete ev; ev = nullptr; } if (ret != 0) goto end; } else { /* It is a Rotate_log_event, Format_description_log_event event or other type event doesn't belong to the transaction. */ delete ev; ev = nullptr; } } else { /* IO error happens if error_type is not READ_EOF, otherwise it arrives the end of the relay log */ if (relaylog_file_reader.get_error_type() != Binlog_read_error::READ_EOF) { LogErr(ERROR_LEVEL, ER_RPL_WORKER_CANT_READ_RELAY_LOG, rli->get_event_relay_log_name(), relaylog_file_reader.position()); goto end; } if (rli->relay_log.find_next_relay_log(file_name)) { LogErr(ERROR_LEVEL, ER_RPL_WORKER_CANT_FIND_NEXT_RELAY_LOG, file_name); goto end; } file_number = relay_log_name_to_number(file_name); relaylog_file_reader.close(); start_relay_pos = BIN_LOG_HEADER_SIZE; } } error = false; end: return error; } /* Find database entry from map_db_to_worker hash table. */ static db_worker_hash_entry *find_entry_from_db_map(const char *dbname, Relay_log_info *rli) { db_worker_hash_entry *entry = nullptr; mysql_mutex_lock(&rli->slave_worker_hash_lock); entry = find_or_nullptr(rli->mapping_db_to_worker, dbname); mysql_mutex_unlock(&rli->slave_worker_hash_lock); return entry; } /* Initialize Log_event::mts_assigned_partitions array. It is for transaction retry and is only called when retrying a transaction by workers. */ void Slave_worker::assign_partition_db(Log_event *ev) { Mts_db_names mts_dbs; int i; ev->get_mts_dbs(&mts_dbs, c_rli->rpl_filter); if (mts_dbs.num == OVER_MAX_DBS_IN_EVENT_MTS) ev->mts_assigned_partitions[0] = find_entry_from_db_map("", c_rli); else for (i = 0; i < mts_dbs.num; i++) ev->mts_assigned_partitions[i] = find_entry_from_db_map(mts_dbs.name[i], c_rli); } // returns the next available! (TODO: incompatible to circurla_buff method!!!) static int en_queue(Slave_jobs_queue *jobs, Slave_job_item *item) { if (jobs->avail == jobs->size) { DBUG_ASSERT(jobs->avail == jobs->m_Q.size()); return -1; } // store jobs->m_Q[jobs->avail] = *item; // pre-boundary cond if (jobs->entry == jobs->size) jobs->entry = jobs->avail; jobs->avail = (jobs->avail + 1) % jobs->size; jobs->len++; // post-boundary cond if (jobs->avail == jobs->entry) jobs->avail = jobs->size; DBUG_ASSERT(jobs->avail == jobs->entry || jobs->len == (jobs->avail >= jobs->entry) ? (jobs->avail - jobs->entry) : (jobs->size + jobs->avail - jobs->entry)); return jobs->avail; } /** return the value of @c data member of the head of the queue. */ void *head_queue(Slave_jobs_queue *jobs, Slave_job_item *ret) { if (jobs->entry == jobs->size) { DBUG_ASSERT(jobs->len == 0); ret->data = nullptr; // todo: move to caller return nullptr; } *ret = jobs->m_Q[jobs->entry]; DBUG_ASSERT(ret->data); // todo: move to caller return ret; } /** return a job item through a struct which point is supplied via argument. */ Slave_job_item *de_queue(Slave_jobs_queue *jobs, Slave_job_item *ret) { if (jobs->entry == jobs->size) { DBUG_ASSERT(jobs->len == 0); return nullptr; } *ret = jobs->m_Q[jobs->entry]; jobs->len--; // pre boundary cond if (jobs->avail == jobs->size) jobs->avail = jobs->entry; jobs->entry = (jobs->entry + 1) % jobs->size; // post boundary cond if (jobs->avail == jobs->entry) jobs->entry = jobs->size; DBUG_ASSERT(jobs->entry == jobs->size || (jobs->len == (jobs->avail >= jobs->entry) ? (jobs->avail - jobs->entry) : (jobs->size + jobs->avail - jobs->entry))); return ret; } /** Coordinator enqueues a job item into a Worker private queue. @param job_item a pointer to struct carrying a reference to an event @param worker a pointer to the assigned Worker struct @param rli a pointer to Relay_log_info of Coordinator @return false Success. true Thread killed or worker stopped while waiting for successful enqueue. */ bool append_item_to_jobs(slave_job_item *job_item, Slave_worker *worker, Relay_log_info *rli) { THD *thd = rli->info_thd; int ret = -1; size_t ev_size = job_item->data->common_header->data_written; ulonglong new_pend_size; PSI_stage_info old_stage; DBUG_ASSERT(thd == current_thd); mysql_mutex_lock(&rli->pending_jobs_lock); new_pend_size = rli->mts_pending_jobs_size + ev_size; bool big_event = (ev_size > rli->mts_pending_jobs_size_max); /* C waits basing on *data* sizes in the queues. If it is a big event (event size is greater than slave_pending_jobs_size_max but less than slave_max_allowed_packet), it will wait for all the jobs in the workers's queue to be completed. If it is normal event (event size is less than slave_pending_jobs_size_max), then it will wait for enough empty memory to keep the event in one of the workers's queue. NOTE: Receiver thread (I/O thread) is taking care of restricting the event size to slave_max_allowed_packet. If an event from the master is bigger than this value, IO thread will be stopped with error ER_NET_PACKET_TOO_LARGE. */ while ((!big_event && new_pend_size > rli->mts_pending_jobs_size_max) || (big_event && rli->mts_pending_jobs_size != 0)) { rli->mts_wq_oversize = true; rli->wq_size_waits_cnt++; // waiting due to the total size thd->ENTER_COND(&rli->pending_jobs_cond, &rli->pending_jobs_lock, &stage_slave_waiting_worker_to_free_events, &old_stage); mysql_cond_wait(&rli->pending_jobs_cond, &rli->pending_jobs_lock); mysql_mutex_unlock(&rli->pending_jobs_lock); thd->EXIT_COND(&old_stage); if (thd->killed) return true; if (rli->wq_size_waits_cnt % 10 == 1) LogErr(INFORMATION_LEVEL, ER_RPL_MTS_SLAVE_COORDINATOR_HAS_WAITED, rli->wq_size_waits_cnt, ev_size); mysql_mutex_lock(&rli->pending_jobs_lock); new_pend_size = rli->mts_pending_jobs_size + ev_size; } rli->pending_jobs++; rli->mts_pending_jobs_size = new_pend_size; rli->mts_events_assigned++; mysql_mutex_unlock(&rli->pending_jobs_lock); /* Sleep unless there is an underrunning Worker and the current Worker queue is empty or filled lightly (not more than underrun level). */ if (rli->mts_wq_underrun_w_id == MTS_WORKER_UNDEF && worker->jobs.len > worker->underrun_level) { /* todo: experiment with weight to get a good approximation formula. Max possible nap time is choosen 1 ms. The bigger the excessive overrun counter the longer the nap. */ ulong nap_weight = rli->mts_wq_excess_cnt + 1; /* Nap time is a product of a weight factor and the basic nap unit. The weight factor is proportional to the worker queues overrun excess counter. For example when there were only one overruning Worker the max nap_weight as 0.1 * worker->jobs.size would be about 1600 so the max nap time is approx 0.008 secs. Such value is not reachable because of min(). Notice, granularity of sleep depends on the resolution of the software clock, High-Resolution Timer (HRT) configuration. Without HRT the precision of wake-up through @c select() may be greater or equal 1 ms. So don't expect the nap last a prescribed fraction of 1 ms in such case. */ my_sleep(min(1000, nap_weight * rli->mts_coordinator_basic_nap)); rli->mts_wq_no_underrun_cnt++; } mysql_mutex_lock(&worker->jobs_lock); // possible WQ overfill while (worker->running_status == Slave_worker::RUNNING && !thd->killed && (ret = en_queue(&worker->jobs, job_item)) == -1) { thd->ENTER_COND(&worker->jobs_cond, &worker->jobs_lock, &stage_slave_waiting_worker_queue, &old_stage); worker->jobs.overfill = true; worker->jobs.waited_overfill++; rli->mts_wq_overfill_cnt++; mysql_cond_wait(&worker->jobs_cond, &worker->jobs_lock); mysql_mutex_unlock(&worker->jobs_lock); thd->EXIT_COND(&old_stage); mysql_mutex_lock(&worker->jobs_lock); } if (ret != -1) { worker->curr_jobs++; if (worker->jobs.len == 1) mysql_cond_signal(&worker->jobs_cond); mysql_mutex_unlock(&worker->jobs_lock); } else { mysql_mutex_unlock(&worker->jobs_lock); mysql_mutex_lock(&rli->pending_jobs_lock); rli->pending_jobs--; // roll back of the prev incr rli->mts_pending_jobs_size -= ev_size; mysql_mutex_unlock(&rli->pending_jobs_lock); } return (-1 != ret ? false : true); } /** Remove a job item from the given workers job queue. It also updates related status. param[in] job_item The job item will be removed param[in] worker The worker which job_item belongs to. param[in] rli slave's relay log info object. */ static void remove_item_from_jobs(slave_job_item *job_item, Slave_worker *worker, Relay_log_info *rli) { Log_event *ev = job_item->data; mysql_mutex_lock(&worker->jobs_lock); de_queue(&worker->jobs, job_item); /* possible overfill */ if (worker->jobs.len == worker->jobs.size - 1 && worker->jobs.overfill == true) { worker->jobs.overfill = false; // todo: worker->hungry_cnt++; mysql_cond_signal(&worker->jobs_cond); } mysql_mutex_unlock(&worker->jobs_lock); /* statistics */ /* todo: convert to rwlock/atomic write */ mysql_mutex_lock(&rli->pending_jobs_lock); rli->pending_jobs--; rli->mts_pending_jobs_size -= ev->common_header->data_written; DBUG_ASSERT(rli->mts_pending_jobs_size < rli->mts_pending_jobs_size_max); /* The positive branch is underrun: number of pending assignments is less than underrun level. Zero of jobs.len has to reset underrun w_id as the worker may get the next piece of assignement in a long time. */ if (worker->underrun_level > worker->jobs.len && worker->jobs.len != 0) { rli->mts_wq_underrun_w_id = worker->id; } else if (rli->mts_wq_underrun_w_id == worker->id) { // reset only own marking rli->mts_wq_underrun_w_id = MTS_WORKER_UNDEF; } /* Overrun handling. Incrementing the Worker private and the total excess counter corresponding to number of events filled above the overrun_level. The increment amount to the total counter is a difference between the current and the previous private excess (worker->wq_overrun_cnt). When the current queue length drops below overrun_level the global counter is decremented, the local is reset. */ if (worker->overrun_level < worker->jobs.len) { ulong last_overrun = worker->wq_overrun_cnt; ulong excess_delta; /* current overrun */ worker->wq_overrun_cnt = worker->jobs.len - worker->overrun_level; excess_delta = worker->wq_overrun_cnt - last_overrun; worker->excess_cnt += excess_delta; rli->mts_wq_excess_cnt += excess_delta; rli->mts_wq_overrun_cnt++; // statistics // guarding correctness of incrementing in case of the only one Worker DBUG_ASSERT(rli->workers.size() != 1 || rli->mts_wq_excess_cnt == worker->wq_overrun_cnt); } else if (worker->excess_cnt > 0) { // When level drops below the total excess is decremented by the // value of the worker's contribution to the total excess. rli->mts_wq_excess_cnt -= worker->excess_cnt; worker->excess_cnt = 0; worker->wq_overrun_cnt = 0; // and the local is reset DBUG_ASSERT(rli->mts_wq_excess_cnt >= 0); DBUG_ASSERT(rli->mts_wq_excess_cnt == 0 || rli->workers.size() > 1); } /* coordinator can be waiting */ if (rli->mts_pending_jobs_size < rli->mts_pending_jobs_size_max && rli->mts_wq_oversize) // TODO: unit/general test wq_oversize { rli->mts_wq_oversize = false; mysql_cond_signal(&rli->pending_jobs_cond); } mysql_mutex_unlock(&rli->pending_jobs_lock); worker->events_done++; } /** Worker's routine to wait for a new assignement through @c append_item_to_jobs() @param worker a pointer to the waiting Worker struct @param job_item a pointer to struct carrying a reference to an event @return NULL failure or a-pointer to an item. */ static struct slave_job_item *pop_jobs_item(Slave_worker *worker, Slave_job_item *job_item) { THD *thd = worker->info_thd; mysql_mutex_lock(&worker->jobs_lock); job_item->data = nullptr; while (!job_item->data && !thd->killed && (worker->running_status == Slave_worker::RUNNING || worker->running_status == Slave_worker::STOP)) { PSI_stage_info old_stage; if (set_max_updated_index_on_stop(worker, job_item)) break; if (job_item->data == nullptr) { worker->wq_empty_waits++; thd->ENTER_COND(&worker->jobs_cond, &worker->jobs_lock, &stage_slave_waiting_event_from_coordinator, &old_stage); mysql_cond_wait(&worker->jobs_cond, &worker->jobs_lock); mysql_mutex_unlock(&worker->jobs_lock); thd->EXIT_COND(&old_stage); mysql_mutex_lock(&worker->jobs_lock); } } if (job_item->data) worker->curr_jobs--; mysql_mutex_unlock(&worker->jobs_lock); thd_proc_info(worker->info_thd, "Executing event"); return job_item; } /** Report a not yet reported error to the coordinator if necessary. All issues detected when applying binary log events are reported using rli->report(), but when an issue is not reported by the log event being applied, there is a workaround at handle_slave_sql() to report the issue also using rli->report() for the STS applier (or the MTS coordinator). This function implements the workaround for a MTS worker. @param worker the worker to be evaluated. */ void report_error_to_coordinator(Slave_worker *worker) { THD *thd = worker->info_thd; /* It is possible that the worker had failed to apply the event but did not reported about the failure using rli->report(). An example of such cases are failures caused by setting GTID_NEXT variable with an unsupported GTID mode (GTID_SET when GTID_MODE = OFF, anonymous GTID when GTID_MODE = ON). */ if (thd->is_error()) { char const *const errmsg = thd->get_stmt_da()->message_text(); DBUG_PRINT("info", ("thd->get_stmt_da()->get_mysql_errno()=%d; " "worker->last_error.number=%d", thd->get_stmt_da()->mysql_errno(), worker->last_error().number)); if (worker->last_error().number == 0 && /* When another worker that should commit before the current worker being evaluated has failed and the commit order should be preserved the current worker was asked to roll back and would stop with the ER_SLAVE_WORKER_STOPPED_PREVIOUS_THD_ERROR not yet reported to the coordinator. Reporting this error to the coordinator would be a mistake and would mask the real issue that lead to the MTS stop as the coordinator reports only the last error reported to it as the cause of the MTS failure. So, we should skip reporting the error if it was reported because the current transaction had to be rolled back by a failure in a previous transaction in the commit order while the current transaction was waiting to be committed. */ thd->get_stmt_da()->mysql_errno() != ER_SLAVE_WORKER_STOPPED_PREVIOUS_THD_ERROR) { /* This function is reporting an error which was not reported while executing exec_relay_log_event(). */ worker->report(ERROR_LEVEL, thd->get_stmt_da()->mysql_errno(), "%s", errmsg); } } } /** apply one job group. @note the function maintains worker's CGEP and modifies APH, updates the current group item in GAQ via @c slave_worker_ends_group(). param[in] worker the worker which calls it. param[in] rli slave's relay log info object. return returns 0 if the group of jobs are applied successfully, otherwise returns an error code. */ int slave_worker_exec_job_group(Slave_worker *worker, Relay_log_info *rli) { struct slave_job_item item = {nullptr, 0, 0}; struct slave_job_item *job_item = &item; THD *thd = worker->info_thd; bool seen_gtid = false; bool seen_begin = false; int error = 0; Log_event *ev = nullptr; uint start_relay_number; my_off_t start_relay_pos; DBUG_TRACE; if (unlikely(worker->trans_retries > 0)) worker->trans_retries = 0; job_item = pop_jobs_item(worker, job_item); start_relay_number = job_item->relay_number; start_relay_pos = job_item->relay_pos; /* Current event with Worker associator. */ RLI_current_event_raii worker_curr_ev(worker, ev); while (1) { Slave_job_group *ptr_g; if (unlikely(thd->killed || worker->running_status == Slave_worker::STOP_ACCEPTED)) { DBUG_ASSERT(worker->running_status != Slave_worker::ERROR_LEAVING); // de-queueing and decrement counters is in the caller's exit branch error = -1; goto err; } ev = job_item->data; DBUG_ASSERT(ev != nullptr); DBUG_PRINT("info", ("W_%lu <- job item: %p data: %p thd: %p", worker->id, job_item, ev, thd)); /* Associate the freshly read event with worker. The binding also remains when the loop breaks at the group end event so a DDL Query_log_event as such a breaker would remain pinned to the Worker by the slave info table update and commit time, see slave_worker_ends_group(). */ worker_curr_ev.set_current_event(ev); if (is_gtid_event(ev)) seen_gtid = true; if (!seen_begin && ev->starts_group()) { seen_begin = true; // The current group is started with B-event worker->end_group_sets_max_dbs = true; } set_timespec_nsec(&worker->ts_exec[0], 0); // pre-exec worker->stats_read_time += diff_timespec(&worker->ts_exec[0], &worker->ts_exec[1]); /* Adapting to possible new Format_description_log_event */ ptr_g = rli->gaq->get_job_group(ev->mts_group_idx); if (ptr_g->new_fd_event) { error = worker->set_rli_description_event(ptr_g->new_fd_event); if (unlikely(error)) goto err; ptr_g->new_fd_event = nullptr; } error = worker->slave_worker_exec_event(ev); set_timespec_nsec(&worker->ts_exec[1], 0); // pre-exec worker->stats_exec_time += diff_timespec(&worker->ts_exec[1], &worker->ts_exec[0]); if (error || worker->found_order_commit_deadlock()) { error = worker->retry_transaction(start_relay_number, start_relay_pos, job_item->relay_number, job_item->relay_pos); if (error) goto err; } /* p-event or any other event of B-free (malformed) group can "commit" with logical clock scheduler. In that case worker id points to the only active "exclusive" Worker that processes such malformed group events one by one. WL#7592 refines the original assert disjunction formula with the final disjunct. */ DBUG_ASSERT(seen_begin || is_gtid_event(ev) || ev->get_type_code() == binary_log::QUERY_EVENT || is_mts_db_partitioned(rli) || worker->id == 0 || seen_gtid); if (ev->ends_group() || (!seen_begin && !is_gtid_event(ev) && (ev->get_type_code() == binary_log::QUERY_EVENT || /* break through by LC only in GTID off */ (!seen_gtid && !is_mts_db_partitioned(rli))))) break; remove_item_from_jobs(job_item, worker, rli); /* The event will be used later if worker is NULL, so it is not freed */ if (ev->worker != nullptr) delete ev; job_item = pop_jobs_item(worker, job_item); } DBUG_PRINT("info", (" commits GAQ index %lu, last committed %lu", ev->mts_group_idx, worker->last_group_done_index)); /* The group is applied successfully, so error should be 0 */ worker->slave_worker_ends_group(ev, 0); /* Check if the finished group started with a Gtid_log_event to update the monitoring information */ if (current_thd->rli_slave->is_processing_trx()) { DBUG_EXECUTE_IF("rpl_ps_tables", { const char act[] = "now SIGNAL signal.rpl_ps_tables_apply_before " "WAIT_FOR signal.rpl_ps_tables_apply_finish"; DBUG_ASSERT(opt_debug_sync_timeout > 0); DBUG_ASSERT(!debug_sync_set_action(current_thd, STRING_WITH_LEN(act))); };); if (ev->get_type_code() == binary_log::QUERY_EVENT && ((Query_log_event *)ev)->rollback_injected_by_coord) { /* If this was a rollback event injected by the coordinator because of a partial transaction in the relay log, we must not consider this transaction completed and, instead, clear the monitoring info. */ current_thd->rli_slave->clear_processing_trx(); } else { current_thd->rli_slave->finished_processing(); } DBUG_EXECUTE_IF("rpl_ps_tables", { const char act[] = "now SIGNAL signal.rpl_ps_tables_apply_after_finish " "WAIT_FOR signal.rpl_ps_tables_apply_continue"; DBUG_ASSERT(opt_debug_sync_timeout > 0); DBUG_ASSERT(!debug_sync_set_action(current_thd, STRING_WITH_LEN(act))); };); } #ifndef DBUG_OFF DBUG_PRINT("mts", ("Check_slave_debug_group worker %lu mts_checkpoint_group" " %u processed %lu debug %d\n", worker->id, opt_mts_checkpoint_group, worker->groups_done, DBUG_EVALUATE_IF("check_slave_debug_group", 1, 0))); if (DBUG_EVALUATE_IF("check_slave_debug_group", 1, 0) && opt_mts_checkpoint_group == worker->groups_done) { DBUG_PRINT("mts", ("Putting worker %lu in busy wait.", worker->id)); while (true) my_sleep(6000000); } #endif remove_item_from_jobs(job_item, worker, rli); delete ev; return 0; err: if (error) { report_error_to_coordinator(worker); DBUG_PRINT("info", ("Worker %lu is exiting: killed %i, error %i, " "running_status %d", worker->id, thd->killed.load(), thd->is_error(), worker->running_status)); worker->slave_worker_ends_group(ev, error); /* last done sets post exec */ } return error; } const char *Slave_worker::get_for_channel_str(bool upper_case) const { return c_rli->get_for_channel_str(upper_case); } const uint *Slave_worker::get_table_pk_field_indexes() { return info_slave_worker_table_pk_field_indexes; } uint Slave_worker::get_channel_field_index() { return LINE_FOR_CHANNEL; }