MySQL 5.6-innodb ioスレッド設定を増やす必要があるかどうかはどうすればわかりますか？
Mysqlサーバーをハイエンドシステム用に調整しようとしています。メモリが100 GBを超える16〜32コアホストを使用しています。
既存の設定を調べましたが、innodb_read/write_io_threadsを調整する必要があるかどうかはわかりません。現在はそれぞれ4つだけに設定されています。
| InnoDB | |
=====================================
2019-12-17 07:54:43 7f711dd6d700 INNODB MONITOR OUTPUT
=====================================
Per second averages calculated from the last 9 seconds
-----------------
BACKGROUND THREAD
-----------------
srv_master_thread loops: 2400188 srv_active, 0 srv_shutdown, 265 srv_idle
srv_master_thread log flush and writes: 894
----------
SEMAPHORES
----------
OS WAIT ARRAY INFO: reservation count 806244840
OS WAIT ARRAY INFO: signal count 1019059878
Mutex spin waits 10940244001, rounds 62338475851, OS waits 590825553
RW-shared spins 566475375, rounds 5765275559, OS waits 128474028
RW-excl spins 19695565, rounds 1326338619, OS waits 15787881
Spin rounds per wait: -32.06 mutex, 10.18 RW-shared, 67.34 RW-excl
--------
FILE I/O
--------
I/O thread 0 state: waiting for i/o request (insert buffer thread)
I/O thread 1 state: waiting for i/o request (log thread)
I/O thread 2 state: waiting for i/o request (read thread)
I/O thread 3 state: waiting for i/o request (read thread)
I/O thread 4 state: waiting for i/o request (read thread)
I/O thread 5 state: waiting for i/o request (read thread)
I/O thread 6 state: waiting for i/o request (write thread)
I/O thread 7 state: waiting for i/o request (write thread)
I/O thread 8 state: waiting for i/o request (write thread)
I/O thread 9 state: waiting for i/o request (write thread)
Pending normal aio reads: 0 [0, 0, 0, 0] , aio writes: 0 [0, 0, 0, 0] ,
ibuf aio reads: 0, log i/o's: 0, sync i/o's: 0
Pending flushes (fsync) log: 0; buffer pool: 0
29500680050 OS file reads, 1193269217 OS file writes, 193602148 OS fsyncs
117.54 reads/s, 19527 avg bytes/read, 342.96 writes/s, 37.77 fsyncs/s
mysql> show status like 'max_used_connections';
+----------------------+-------+
| Variable_name | Value |
+----------------------+-------+
| Max_used_connections | 174 |
+----------------------+-------+
Innodb ioスレッドがアイドル状態になっているように見えますが、接続されて実行を待機しているスレッドの数が多いため、直感に反します。
指標を間違って読んでいるだけですか？ ioスレッドの設定を上げる必要がありますか？
編集：
mysql> SHOW GLOBAL STATUS;
+-----------------------------------------------+--------------------------------------------------+
| Variable_name | Value |
+-----------------------------------------------+--------------------------------------------------+
| Aborted_clients | 106863 |
| Aborted_connects | 70 |
| Binlog_cache_disk_use | 0 |
| Binlog_cache_use | 0 |
| Binlog_stmt_cache_disk_use | 0 |
| Binlog_stmt_cache_use | 0 |
| Bytes_received | 1625547525701 |
| Bytes_sent | 2286003139405 |
| Com_admin_commands | 8499339 |
| Com_change_db | 1 |
| Com_commit | 590982562 |
| Com_delete | 107601707 |
| Com_help | 0 |
| Com_insert | 92217681 |
| Com_rollback | 471568007 |
| Com_rollback_to_savepoint | 0 |
| Com_savepoint | 0 |
| Com_select | 2839611448 |
| Com_set_option | 1393872258 |
| Com_signal | 0 |
| Com_show_databases | 17 |
| Com_show_engine_logs | 0 |
| Com_show_engine_mutex | 0 |
| Com_show_engine_status | 4 |
| Com_show_events | 0 |
| Com_show_errors | 0 |
| Com_show_fields | 369 |
| Com_show_function_code | 0 |
| Com_show_function_status | 0 |
| Com_show_grants | 0 |
| Com_show_keys | 111 |
| Com_show_status | 23 |
| Com_show_storage_engines | 0 |
| Com_show_table_status | 0 |
| Com_show_tables | 21 |
| Com_show_triggers | 0 |
| Com_show_variables | 342355 |
| Com_update | 841346886 |
| Compression | OFF |
| Connection_errors_accept | 0 |
| Connection_errors_internal | 0 |
| Connection_errors_max_connections | 0 |
| Connection_errors_peer_address | 0 |
| Connection_errors_select | 0 |
| Connection_errors_tcpwrap | 0 |
| Connections | 342450 |
| Created_tmp_disk_tables | 2334 |
| Created_tmp_files | 8 |
| Created_tmp_tables | 356072 |
| Delayed_errors | 0 |
| Delayed_insert_threads | 0 |
| Delayed_writes | 0 |
| Flush_commands | 1 |
| Handler_commit | 4470737313 |
| Handler_delete | 82094865 |
| Handler_discover | 0 |
| Handler_external_lock | 7759509648 |
| Handler_mrr_init | 0 |
| Handler_prepare | 0 |
| Handler_read_first | 1653297601 |
| Handler_read_key | 6492652384 |
| Handler_read_last | 0 |
| Handler_read_next | 5142902623 |
| Handler_read_prev | 0 |
| Handler_read_rnd | 3366143 |
| Handler_read_rnd_next | 3314986049 |
| Handler_rollback | 471332451 |
| Handler_savepoint | 0 |
| Handler_savepoint_rollback | 0 |
| Handler_update | 841346880 |
| Handler_write | 183314643 |
| Innodb_buffer_pool_dump_status | not started |
| Innodb_buffer_pool_load_status | Buffer pool(s) load completed at 191121 19:04:32 |
| Innodb_buffer_pool_pages_data | 509389 |
| Innodb_buffer_pool_bytes_data | 8345829376 |
| Innodb_buffer_pool_pages_dirty | 51724 |
| Innodb_buffer_pool_bytes_dirty | 847446016 |
| Innodb_buffer_pool_pages_flushed | 831165527 |
| Innodb_buffer_pool_pages_free | 6243 |
| Innodb_buffer_pool_pages_misc | 8652 |
| Innodb_buffer_pool_pages_total | 524284 |
| Innodb_buffer_pool_read_ahead_rnd | 0 |
| Innodb_buffer_pool_read_ahead | 0 |
| Innodb_buffer_pool_read_ahead_evicted | 18274 |
| Innodb_buffer_pool_read_requests | 116508588463 |
| Innodb_buffer_pool_reads | 2534236537 |
| Innodb_buffer_pool_wait_free | 0 |
| Innodb_buffer_pool_write_requests | 9553501411 |
| Innodb_data_fsyncs | 100038238 |
| Innodb_data_pending_fsyncs | 0 |
| Innodb_data_pending_reads | 0 |
| Innodb_data_pending_writes | 0 |
| Innodb_data_read | 46554305269760 |
| Innodb_data_reads | 2840557270 |
| Innodb_data_writes | 772657004 |
| Innodb_data_written | 28407884982784 |
| Innodb_dblwr_pages_written | 831165527 |
| Innodb_dblwr_writes | 19505074 |
| Innodb_have_atomic_builtins | ON |
| Innodb_log_waits | 0 |
| Innodb_log_write_requests | 2932109671 |
| Innodb_log_writes | 2358858 |
| Innodb_os_log_fsyncs | 2534641 |
| Innodb_os_log_pending_fsyncs | 0 |
| Innodb_os_log_pending_writes | 0 |
| Innodb_os_log_written | 1172130567680 |
| Innodb_page_size | 16384 |
| Innodb_pages_created | 9089369 |
| Innodb_pages_read | 2841543370 |
| Innodb_pages_written | 831165527 |
| Innodb_row_lock_current_waits | 0 |
| Innodb_row_lock_time | 0 |
| Innodb_row_lock_time_avg | 0 |
| Innodb_row_lock_time_max | 0 |
| Innodb_row_lock_waits | 0 |
| Innodb_rows_deleted | 82094865 |
| Innodb_rows_inserted | 175266694 |
| Innodb_rows_read | 10220852902 |
| Innodb_rows_updated | 841346880 |
| Innodb_num_open_files | 24 |
| Innodb_truncated_status_writes | 0 |
| Innodb_available_undo_logs | 128 |
| Key_blocks_not_flushed | 0 |
| Key_blocks_unused | 319666 |
| Key_blocks_used | 0 |
| Key_read_requests | 0 |
| Key_reads | 0 |
| Key_write_requests | 0 |
| Key_writes | 0 |
| Last_query_cost | 0.000000 |
| Last_query_partial_plans | 0 |
| Max_used_connections | 42 |
| Not_flushed_delayed_rows | 0 |
| Open_files | 17 |
| Open_streams | 0 |
| Open_table_definitions | 86 |
| Open_tables | 246 |
| Opened_files | 9475 |
| Opened_table_definitions | 86 |
| Opened_tables | 253 |
| Performance_schema_accounts_lost | 0 |
| Performance_schema_cond_classes_lost | 0 |
| Performance_schema_cond_instances_lost | 0 |
| Performance_schema_digest_lost | 0 |
| Performance_schema_file_classes_lost | 0 |
| Performance_schema_file_handles_lost | 0 |
| Performance_schema_file_instances_lost | 0 |
| Performance_schema_hosts_lost | 0 |
| Performance_schema_locker_lost | 0 |
| Performance_schema_mutex_classes_lost | 0 |
| Performance_schema_mutex_instances_lost | 0 |
| Performance_schema_rwlock_classes_lost | 0 |
| Performance_schema_rwlock_instances_lost | 0 |
| Performance_schema_session_connect_attrs_lost | 0 |
| Performance_schema_socket_classes_lost | 0 |
| Performance_schema_socket_instances_lost | 0 |
| Performance_schema_stage_classes_lost | 0 |
| Performance_schema_statement_classes_lost | 0 |
| Performance_schema_table_handles_lost | 0 |
| Performance_schema_table_instances_lost | 0 |
| Performance_schema_thread_classes_lost | 0 |
| Performance_schema_thread_instances_lost | 0 |
| Performance_schema_users_lost | 0 |
| Prepared_stmt_count | 0 |
| Qcache_free_blocks | 1 |
| Qcache_free_memory | 33536848 |
| Qcache_hits | 0 |
| Qcache_inserts | 0 |
| Qcache_lowmem_prunes | 0 |
| Qcache_not_cached | 2832134371 |
| Qcache_queries_in_cache | 0 |
| Qcache_total_blocks | 1 |
| Queries | 6346278252 |
| Questions | 6337778912 |
| Rsa_public_key | |
| Select_full_join | 111 |
| Select_full_range_join | 0 |
| Select_range | 111074254 |
| Select_range_check | 0 |
| Select_scan | 1062657891 |
| Slave_heartbeat_period | 0.000 |
| Slave_last_heartbeat | |
| Slave_open_temp_tables | 0 |
| Slave_received_heartbeats | 0 |
| Slave_retried_transactions | 0 |
| Slave_running | OFF |
| Slow_launch_threads | 0 |
| Slow_queries | 14115 |
| Sort_merge_passes | 48 |
| Sort_range | 5128 |
| Sort_rows | 1833044 |
| Sort_scan | 1 |
| Table_locks_immediate | 3878704926 |
| Table_locks_waited | 0 |
| Table_open_cache_hits | 3879758717 |
| Table_open_cache_misses | 253 |
| Table_open_cache_overflows | 0 |
| Tc_log_max_pages_used | 0 |
| Tc_log_page_size | 0 |
| Tc_log_page_waits | 0 |
| Threads_cached | 0 |
| Threads_connected | 41 |
| Threads_created | 167939 |
| Threads_running | 2 |
| Uptime | 2246778 |
| Uptime_since_flush_status | 2246778 |
+-----------------------------------------------+--------------------------------------------------+
"バックグラウンドのInnoDB I/Oスレッド数の構成" の段落3によると：
ハイエンドのI/Oサブシステムがあり、SHOW ENGINE INNODB STATUS出力に保留中の読み取り要求が64×innodb_read_io_threadsを超える場合は、innodb_read_io_threadsの値を増やすことでパフォーマンスを向上させることができます。
上記のSHOW ENGINE INNODB STATUS\Gを考えると、
Pending normal aio reads: 0 [0, 0, 0, 0] , aio writes: 0 [0, 0, 0, 0] ,
すべてのI/Oスレッドについて0があるため、その時点で保留中のスレッドはありません。 0ではなく2桁または3桁の数字が表示されるようになった場合、InnoDBで読み取りと書き込みが保留されます。
これは、グローバルステータスでも確認できます
| Innodb_data_pending_reads | 0
| Innodb_data_pending_writes | 0
示されているように、mysqldが最後に起動してから、InnoDBストレージエンジンで保留中の読み取りまたは書き込みが発生していません。
Innodb_data_pending_readsまたはInnodb_data_pending_writesを定期的に監視できます
SHOW ENGINE INNODB STATUSをポーリングして、Pending normal aioで非ゼロを探すこともできます。
個人的に、私は innodb_read_io_threads と innodb_write_io_threads の両方を8に上げて、Percona Serverのデフォルト値と一致させ、1日と呼びます。
Innodbバッファープールを適切に使用している。
Innodb_data_pending_readsは少し外れ値です。そのレベルを監視してください。ゼロでないことが多い場合は、innodb_read_io_threadsを8程度にすると、競合が減ります。
これはまだあなたのストレージハードウェアと同じくらい良いです。