diff options
Diffstat (limited to 'storage/innobase/dict/dict0defrag_bg.cc')
| -rw-r--r-- | storage/innobase/dict/dict0defrag_bg.cc | 434 |
1 files changed, 434 insertions, 0 deletions
diff --git a/storage/innobase/dict/dict0defrag_bg.cc b/storage/innobase/dict/dict0defrag_bg.cc new file mode 100644 index 00000000..bec6da8e --- /dev/null +++ b/storage/innobase/dict/dict0defrag_bg.cc @@ -0,0 +1,434 @@ +/***************************************************************************** + +Copyright (c) 2016, 2022, MariaDB Corporation. + +This program is free software; you can redistribute it and/or modify it under +the terms of the GNU General Public License as published by the Free Software +Foundation; version 2 of the License. + +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 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 Street, Fifth Floor, Boston, MA 02110-1335 USA + +*****************************************************************************/ + +/**************************************************//** +@file dict/dict0defrag_bg.cc +Defragmentation routines. + +Created 25/08/2016 Jan Lindström +*******************************************************/ + +#include "dict0dict.h" +#include "dict0stats.h" +#include "dict0stats_bg.h" +#include "dict0defrag_bg.h" +#include "btr0btr.h" +#include "srv0start.h" +#include "trx0trx.h" +#include "lock0lock.h" +#include "row0mysql.h" + +static mysql_mutex_t defrag_pool_mutex; + +/** Iterator type for iterating over the elements of objects of type +defrag_pool_t. */ +typedef defrag_pool_t::iterator defrag_pool_iterator_t; + +/** Pool where we store information on which tables are to be processed +by background defragmentation. */ +defrag_pool_t defrag_pool; + + +/*****************************************************************//** +Initialize the defrag pool, called once during thread initialization. */ +void +dict_defrag_pool_init(void) +/*=======================*/ +{ + ut_ad(!srv_read_only_mode); + mysql_mutex_init(0, &defrag_pool_mutex, nullptr); +} + +/*****************************************************************//** +Free the resources occupied by the defrag pool, called once during +thread de-initialization. */ +void +dict_defrag_pool_deinit(void) +/*=========================*/ +{ + ut_ad(!srv_read_only_mode); + + mysql_mutex_destroy(&defrag_pool_mutex); +} + +/*****************************************************************//** +Get an index from the auto defrag pool. The returned index id is removed +from the pool. +@return true if the pool was non-empty and "id" was set, false otherwise */ +static +bool +dict_stats_defrag_pool_get( +/*=======================*/ + table_id_t* table_id, /*!< out: table id, or unmodified if + list is empty */ + index_id_t* index_id) /*!< out: index id, or unmodified if + list is empty */ +{ + ut_ad(!srv_read_only_mode); + + mysql_mutex_lock(&defrag_pool_mutex); + + if (defrag_pool.empty()) { + mysql_mutex_unlock(&defrag_pool_mutex); + return(false); + } + + defrag_pool_item_t& item = defrag_pool.back(); + *table_id = item.table_id; + *index_id = item.index_id; + + defrag_pool.pop_back(); + + mysql_mutex_unlock(&defrag_pool_mutex); + + return(true); +} + +/*****************************************************************//** +Add an index in a table to the defrag pool, which is processed by the +background stats gathering thread. Only the table id and index id are +added to the list, so the table can be closed after being enqueued and +it will be opened when needed. If the table or index does not exist later +(has been DROPped), then it will be removed from the pool and skipped. */ +void +dict_stats_defrag_pool_add( +/*=======================*/ + const dict_index_t* index) /*!< in: table to add */ +{ + defrag_pool_item_t item; + + ut_ad(!srv_read_only_mode); + + mysql_mutex_lock(&defrag_pool_mutex); + + /* quit if already in the list */ + for (defrag_pool_iterator_t iter = defrag_pool.begin(); + iter != defrag_pool.end(); + ++iter) { + if ((*iter).table_id == index->table->id + && (*iter).index_id == index->id) { + mysql_mutex_unlock(&defrag_pool_mutex); + return; + } + } + + item.table_id = index->table->id; + item.index_id = index->id; + defrag_pool.push_back(item); + if (defrag_pool.size() == 1) { + /* Kick off dict stats optimizer work */ + dict_stats_schedule_now(); + } + mysql_mutex_unlock(&defrag_pool_mutex); +} + +/*****************************************************************//** +Delete a given index from the auto defrag pool. */ +void +dict_stats_defrag_pool_del( +/*=======================*/ + const dict_table_t* table, /*!<in: if given, remove + all entries for the table */ + const dict_index_t* index) /*!< in: if given, remove this index */ +{ + ut_a((table && !index) || (!table && index)); + ut_ad(!srv_read_only_mode); + ut_ad(dict_sys.frozen()); + + mysql_mutex_lock(&defrag_pool_mutex); + + defrag_pool_iterator_t iter = defrag_pool.begin(); + while (iter != defrag_pool.end()) { + if ((table && (*iter).table_id == table->id) + || (index + && (*iter).table_id == index->table->id + && (*iter).index_id == index->id)) { + /* erase() invalidates the iterator */ + iter = defrag_pool.erase(iter); + if (index) + break; + } else { + iter++; + } + } + + mysql_mutex_unlock(&defrag_pool_mutex); +} + +/*****************************************************************//** +Get the first index that has been added for updating persistent defrag +stats and eventually save its stats. */ +static void dict_stats_process_entry_from_defrag_pool(THD *thd) +{ + table_id_t table_id; + index_id_t index_id; + + ut_ad(!srv_read_only_mode); + + /* pop the first index from the auto defrag pool */ + if (!dict_stats_defrag_pool_get(&table_id, &index_id)) + /* no index in defrag pool */ + return; + + /* If the table is no longer cached, we've already lost the in + memory stats so there's nothing really to write to disk. */ + MDL_ticket *mdl= nullptr; + if (dict_table_t *table= + dict_table_open_on_id(table_id, false, DICT_TABLE_OP_OPEN_ONLY_IF_CACHED, + thd, &mdl)) + { + if (dict_index_t *index= !table->corrupted + ? dict_table_find_index_on_id(table, index_id) : nullptr) + if (index->is_btree()) + dict_stats_save_defrag_stats(index); + dict_table_close(table, false, thd, mdl); + } +} + +/** +Get the first index that has been added for updating persistent defrag +stats and eventually save its stats. */ +void dict_defrag_process_entries_from_defrag_pool(THD *thd) +{ + while (!defrag_pool.empty()) + dict_stats_process_entry_from_defrag_pool(thd); +} + +/*********************************************************************//** +Save defragmentation result. +@return DB_SUCCESS or error code */ +dberr_t dict_stats_save_defrag_summary(dict_index_t *index, THD *thd) +{ + if (index->is_ibuf()) + return DB_SUCCESS; + + MDL_ticket *mdl_table= nullptr, *mdl_index= nullptr; + dict_table_t *table_stats= dict_table_open_on_name(TABLE_STATS_NAME, false, + DICT_ERR_IGNORE_NONE); + if (table_stats) + { + dict_sys.freeze(SRW_LOCK_CALL); + table_stats= dict_acquire_mdl_shared<false>(table_stats, thd, &mdl_table); + dict_sys.unfreeze(); + } + if (!table_stats || strcmp(table_stats->name.m_name, TABLE_STATS_NAME)) + { +release_and_exit: + if (table_stats) + dict_table_close(table_stats, false, thd, mdl_table); + return DB_STATS_DO_NOT_EXIST; + } + + dict_table_t *index_stats= dict_table_open_on_name(INDEX_STATS_NAME, false, + DICT_ERR_IGNORE_NONE); + if (index_stats) + { + dict_sys.freeze(SRW_LOCK_CALL); + index_stats= dict_acquire_mdl_shared<false>(index_stats, thd, &mdl_index); + dict_sys.unfreeze(); + } + if (!index_stats) + goto release_and_exit; + if (strcmp(index_stats->name.m_name, INDEX_STATS_NAME)) + { + dict_table_close(index_stats, false, thd, mdl_index); + goto release_and_exit; + } + + trx_t *trx= trx_create(); + trx->mysql_thd= thd; + trx_start_internal(trx); + dberr_t ret= trx->read_only + ? DB_READ_ONLY + : lock_table_for_trx(table_stats, trx, LOCK_X); + if (ret == DB_SUCCESS) + ret= lock_table_for_trx(index_stats, trx, LOCK_X); + row_mysql_lock_data_dictionary(trx); + if (ret == DB_SUCCESS) + ret= dict_stats_save_index_stat(index, time(nullptr), "n_pages_freed", + index->stat_defrag_n_pages_freed, + nullptr, + "Number of pages freed during" + " last defragmentation run.", + trx); + if (ret == DB_SUCCESS) + trx->commit(); + else + trx->rollback(); + + if (table_stats) + dict_table_close(table_stats, true, thd, mdl_table); + if (index_stats) + dict_table_close(index_stats, true, thd, mdl_index); + + row_mysql_unlock_data_dictionary(trx); + trx->free(); + + return ret; +} + +/**************************************************************//** +Gets the number of reserved and used pages in a B-tree. +@return number of pages reserved, or ULINT_UNDEFINED if the index +is unavailable */ +static +ulint +btr_get_size_and_reserved( + dict_index_t* index, /*!< in: index */ + ulint flag, /*!< in: BTR_N_LEAF_PAGES or BTR_TOTAL_SIZE */ + ulint* used, /*!< out: number of pages used (<= reserved) */ + mtr_t* mtr) /*!< in/out: mini-transaction where index + is s-latched */ +{ + ulint dummy; + + ut_ad(mtr->memo_contains(index->lock, MTR_MEMO_SX_LOCK)); + ut_a(flag == BTR_N_LEAF_PAGES || flag == BTR_TOTAL_SIZE); + + if (index->page == FIL_NULL + || dict_index_is_online_ddl(index) + || !index->is_committed() + || !index->table->space) { + return(ULINT_UNDEFINED); + } + + dberr_t err; + buf_block_t* root = btr_root_block_get(index, RW_SX_LATCH, mtr, &err); + *used = 0; + if (!root) { + return ULINT_UNDEFINED; + } + + mtr->x_lock_space(index->table->space); + + ulint n = fseg_n_reserved_pages(*root, PAGE_HEADER + PAGE_BTR_SEG_LEAF + + root->page.frame, used, mtr); + if (flag == BTR_TOTAL_SIZE) { + n += fseg_n_reserved_pages(*root, + PAGE_HEADER + PAGE_BTR_SEG_TOP + + root->page.frame, &dummy, mtr); + *used += dummy; + } + + return(n); +} + +/*********************************************************************//** +Save defragmentation stats for a given index. +@return DB_SUCCESS or error code */ +dberr_t +dict_stats_save_defrag_stats( +/*============================*/ + dict_index_t* index) /*!< in: index */ +{ + if (index->is_ibuf()) + return DB_SUCCESS; + if (!index->is_readable()) + return dict_stats_report_error(index->table, true); + + const time_t now= time(nullptr); + mtr_t mtr; + ulint n_leaf_pages; + mtr.start(); + mtr_sx_lock_index(index, &mtr); + ulint n_leaf_reserved= btr_get_size_and_reserved(index, BTR_N_LEAF_PAGES, + &n_leaf_pages, &mtr); + mtr.commit(); + + if (n_leaf_reserved == ULINT_UNDEFINED) + return DB_SUCCESS; + + THD *thd= current_thd; + MDL_ticket *mdl_table= nullptr, *mdl_index= nullptr; + dict_table_t* table_stats= dict_table_open_on_name(TABLE_STATS_NAME, false, + DICT_ERR_IGNORE_NONE); + if (table_stats) + { + dict_sys.freeze(SRW_LOCK_CALL); + table_stats= dict_acquire_mdl_shared<false>(table_stats, thd, &mdl_table); + dict_sys.unfreeze(); + } + if (!table_stats || strcmp(table_stats->name.m_name, TABLE_STATS_NAME)) + { +release_and_exit: + if (table_stats) + dict_table_close(table_stats, false, thd, mdl_table); + return DB_STATS_DO_NOT_EXIST; + } + + dict_table_t *index_stats= dict_table_open_on_name(INDEX_STATS_NAME, false, + DICT_ERR_IGNORE_NONE); + if (index_stats) + { + dict_sys.freeze(SRW_LOCK_CALL); + index_stats= dict_acquire_mdl_shared<false>(index_stats, thd, &mdl_index); + dict_sys.unfreeze(); + } + if (!index_stats) + goto release_and_exit; + + if (strcmp(index_stats->name.m_name, INDEX_STATS_NAME)) + { + dict_table_close(index_stats, false, thd, mdl_index); + goto release_and_exit; + } + + trx_t *trx= trx_create(); + trx->mysql_thd= thd; + trx_start_internal(trx); + dberr_t ret= trx->read_only + ? DB_READ_ONLY + : lock_table_for_trx(table_stats, trx, LOCK_X); + if (ret == DB_SUCCESS) + ret= lock_table_for_trx(index_stats, trx, LOCK_X); + + row_mysql_lock_data_dictionary(trx); + + if (ret == DB_SUCCESS) + ret= dict_stats_save_index_stat(index, now, "n_page_split", + index->stat_defrag_n_page_split, nullptr, + "Number of new page splits on leaves" + " since last defragmentation.", trx); + + if (ret == DB_SUCCESS) + ret= dict_stats_save_index_stat(index, now, "n_leaf_pages_defrag", + n_leaf_pages, nullptr, + "Number of leaf pages when" + " this stat is saved to disk", trx); + + if (ret == DB_SUCCESS) + ret= dict_stats_save_index_stat(index, now, "n_leaf_pages_reserved", + n_leaf_reserved, nullptr, + "Number of pages reserved for" + " this index leaves" + " when this stat is saved to disk", trx); + + if (ret == DB_SUCCESS) + trx->commit(); + else + trx->rollback(); + + if (table_stats) + dict_table_close(table_stats, true, thd, mdl_table); + if (index_stats) + dict_table_close(index_stats, true, thd, mdl_index); + row_mysql_unlock_data_dictionary(trx); + trx->free(); + + return ret; +} |